1
|
Andersson E, Schulz RW, Almeida F, Kleppe L, Skaftnesmo KO, Kjærner-Semb E, Crespo D, Fjelldal PG, Hansen TJ, Norberg B, Edvardsen RB, Wargelius A. Loss of Fshr Prevents Testicular Maturation in Atlantic Salmon (Salmo salar L.). Endocrinology 2024; 165:bqae013. [PMID: 38298132 PMCID: PMC10878062 DOI: 10.1210/endocr/bqae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 01/26/2024] [Accepted: 01/29/2024] [Indexed: 02/02/2024]
Abstract
Early puberty poses a significant challenge for male Atlantic salmon in aquaculture due to its negative impact on growth and welfare. The regulation of puberty in vertebrates involves 2 key reproductive hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and their gonadal receptors. In male mice lacking FSH receptor, testes size is reduced, but fertility is maintained, while medaka and zebrafish with a disrupted fshr gene exhibit near normal testis size and fertility. In these fishes both Fsh and Lh are present during puberty and Lh may rescue fertility, while in salmonid fish only Fsh is present in the circulation during puberty. Using CRISPR-Cas9, we produced crispants with a high prevalence of fshr mutations at the target site, which remained fertile, although more than half showed a testis development deviating from wild-type (wt) males. Crossing out these F0 crispants to each other produced a viable F1 generation showing frameshift (fshr-/-) or in-frame mutations (fshrif/if). Nearly all wt males matured while all fshr-/- males remained immature with small testes containing A spermatogonia as the furthest developed germ cell type and prepubertal plasma androgen levels. Also, the pituitary transcript levels of gnrhr2bba and lhb, but not for fshb, were reduced in the fshr-/- males compared with maturing males. More than half of the fshrif/if mutant males showed no or a delayed maturation. In conclusion, Atlantic salmon show the unique characteristic that loss of Fshr function alone results in male infertility, offering new opportunities to control precocious puberty or fertility in salmon.
Collapse
Affiliation(s)
- Eva Andersson
- Institute of Marine Research, NO-5817 Bergen, Norway
| | - Rüdiger W Schulz
- Institute of Marine Research, NO-5817 Bergen, Norway
- Science Faculty, Department Biology, Utrecht University, NL-3584 CH Utrecht, The Netherlands
| | | | - Lene Kleppe
- Institute of Marine Research, NO-5817 Bergen, Norway
| | | | | | - Diego Crespo
- Institute of Marine Research, NO-5817 Bergen, Norway
| | | | | | | | | | | |
Collapse
|
2
|
Yilmaz O, Jensen AM, Harboe T, Møgster M, Jensen RM, Mjaavatten O, Birkeland E, Spriet E, Sandven L, Furmanek T, Berven FS, Wargelius A, Norberg B. Quantitative proteome profiling reveals molecular hallmarks of egg quality in Atlantic halibut: impairments of transcription and protein folding impede protein and energy homeostasis during early development. BMC Genomics 2022; 23:635. [PMID: 36071374 PMCID: PMC9450261 DOI: 10.1186/s12864-022-08859-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022] Open
Abstract
Background Tandem mass tag spectrometry (TMT labeling-LC-MS/MS) was utilized to examine the global proteomes of Atlantic halibut eggs at the 1-cell-stage post fertilization. Comparisons were made between eggs judged to be of good quality (GQ) versus poor quality (BQ) as evidenced by their subsequent rates of survival for 12 days. Altered abundance of selected proteins in BQ eggs was confirmed by parallel reaction monitoring spectrometry (PRM-LC-MS/MS). Correspondence of protein levels to expression of related gene transcripts was examined via qPCR. Potential mitochondrial differences between GQ and BQ eggs were assessed by transmission electron microscopy (TEM) and measurements of mitochondrial DNA (mtDNA) levels. Results A total of 115 proteins were found to be differentially abundant between GQ and BQ eggs. Frequency distributions of these proteins indicated higher protein folding activity in GQ eggs compared to higher transcription and protein degradation activities in BQ eggs. BQ eggs were also significantly enriched with proteins related to mitochondrial structure and biogenesis. Quantitative differences in abundance of several proteins with parallel differences in their transcript levels were confirmed in egg samples obtained over three consecutive reproductive seasons. The observed disparities in global proteome profiles suggest impairment of protein and energy homeostasis related to unfolded protein response and mitochondrial stress in BQ eggs. TEM revealed BQ eggs to contain significantly higher numbers of mitochondria, but differences in corresponding genomic mtDNA (mt-nd5 and mt-atp6) levels were not significant. Mitochondria from BQ eggs were significantly smaller with a more irregular shape and a higher number of cristae than those from GQ eggs. Conclusion The results of this study indicate that BQ Atlantic halibut eggs are impaired at both transcription and translation levels leading to endoplasmic reticulum and mitochondrial disorders. Observation of these irregularities over three consecutive reproductive seasons in BQ eggs from females of diverse background, age and reproductive experience indicates that they are a hallmark of poor egg quality. Additional research is needed to discover when in oogenesis and under what circumstances these defects may arise. The prevalence of this suite of markers in BQ eggs of diverse vertebrate species also begs investigation. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08859-0.
Collapse
Affiliation(s)
- Ozlem Yilmaz
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway.
| | | | - Torstein Harboe
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
| | - Margareth Møgster
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
| | | | - Olav Mjaavatten
- Department of Biomedicine, The Proteomics Facility of the University of Bergen (PROBE), 5009, Bergen, Norway
| | - Even Birkeland
- Department of Biomedicine, The Proteomics Facility of the University of Bergen (PROBE), 5009, Bergen, Norway
| | - Endy Spriet
- Department of Biomedicine, The Molecular Imaging Center (MIC), University of Bergen, 5009, Bergen, Norway
| | - Linda Sandven
- Department of Biomedicine, The Molecular Imaging Center (MIC), University of Bergen, 5009, Bergen, Norway
| | - Tomasz Furmanek
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - Frode S Berven
- Department of Biomedicine, The Proteomics Facility of the University of Bergen (PROBE), 5009, Bergen, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817, Bergen, Norway
| | - Birgitta Norberg
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
| |
Collapse
|
3
|
Crespo D, Skaftnesmo KO, Kjærner-Semb E, Yilmaz O, Norberg B, Olausson S, Vogelsang P, Bogerd J, Kleppe L, Edvardsen RB, Andersson E, Wargelius A, Hansen TJ, Fjelldal PG, Schulz RW. Pituitary Gonadotropin Gene Expression During Induced Onset of Postsmolt Maturation in Male Atlantic Salmon: In Vivo and Tissue Culture Studies. Front Endocrinol (Lausanne) 2022; 13:826920. [PMID: 35370944 PMCID: PMC8964956 DOI: 10.3389/fendo.2022.826920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/17/2022] [Indexed: 12/25/2022] Open
Abstract
Precocious male maturation causes reduced welfare and increased production costs in Atlantic salmon (Salmo salar) aquaculture. The pituitary produces and releases follicle-stimulating hormone (Fsh), the gonadotropin triggering puberty in male salmonids. However, little is known about how Fsh production is regulated in Atlantic salmon. We examined, in vivo and ex vivo, transcriptional changes of gonadotropin-related genes accompanying the initial steps of testis maturation, in pituitaries of males exposed to photoperiod and temperature conditions promoting maturation (constant light and 16°C). Pituitary fshb, lhb and gnrhr2bba transcripts increased in vivo in maturing males (gonado-somatic index > 0.1%). RNA sequencing (RNAseq) analysis using pituitaries from genetically similar males carrying the same genetic predisposition to mature, but differing by responding or not responding to stimulatory environmental conditions, revealed 144 differentially expressed genes, ~2/3rds being up-regulated in responders, including fshb and other pituitary hormones, steroid-related and other puberty-associated transcripts. Functional enrichment analyses confirmed gene involvement in hormone/steroid production and gonad development. In ex vivo studies, whole pituitaries were exposed to a selection of hormones and growth factors. Gonadotropin-releasing hormone (Gnrh), 17β-estradiol (E2) and 11-ketotestosterone (11-KT) up-regulated gnrhr2bba and lhb, while fshb was up-regulated by Gnrh but down-regulated by 11-KT in pituitaries from immature males. Also pituitaries from maturing males responded to Gnrh and sex steroids by increased gnrhr2bba and lhb transcript levels, but fshb expression remained unchanged. Growth factors (inhibin A, activin A and insulin-like growth factor 1) did not change gnrhr2bba, lhb or fshb transcript levels in pituitaries either from immature or maturing males. Additional pituitary ex vivo studies on candidates identified by RNAseq showed that these transcripts were preferentially regulated by Gnrh and sex steroids, but not by growth factors, and that Gnrh/sex steroids were less effective when incubating pituitaries from maturing males. Our results suggest that a yet to be characterized mechanism up-regulating fshb expression in the salmon pituitary is activated in response to stimulatory environmental conditions prior to morphological signs of testis maturation, and that the transcriptional program associated with this mechanism becomes unresponsive or less responsive to most stimulators ex vivo once males had entered pubertal developmental in vivo.
Collapse
Affiliation(s)
- Diego Crespo
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
- *Correspondence: Diego Crespo,
| | - Kai Ove Skaftnesmo
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Erik Kjærner-Semb
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Ozlem Yilmaz
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Austevoll Research Station, Storebø, Norway
| | - Birgitta Norberg
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Austevoll Research Station, Storebø, Norway
| | - Sara Olausson
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Austevoll Research Station, Storebø, Norway
| | - Petra Vogelsang
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Jan Bogerd
- Reproductive Biology Group, Division Developmental Biology, Department Biology, Science Faculty, Utrecht University, Utrecht, Netherlands
| | - Lene Kleppe
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Rolf B. Edvardsen
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Eva Andersson
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Anna Wargelius
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
| | - Tom J. Hansen
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Matre Research Station, Matredal, Norway
| | - Per Gunnar Fjelldal
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Matre Research Station, Matredal, Norway
| | - Rüdiger W. Schulz
- Research Group Reproduction and Developmental Biology, Institute of Marine Research, Bergen, Norway
- Reproductive Biology Group, Division Developmental Biology, Department Biology, Science Faculty, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
4
|
Straume AH, Kjærner-Semb E, Skaftnesmo KO, Güralp H, Lillico S, Wargelius A, Edvardsen RB. Single nucleotide replacement in the Atlantic salmon genome using CRISPR/Cas9 and asymmetrical oligonucleotide donors. BMC Genomics 2021; 22:563. [PMID: 34294050 PMCID: PMC8296724 DOI: 10.1186/s12864-021-07823-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/17/2021] [Indexed: 12/12/2022] Open
Abstract
Background New breeding technologies (NBT) using CRISPR/Cas9-induced homology directed repair (HDR) has the potential to expedite genetic improvement in aquaculture. The long generation time in Atlantic salmon makes breeding an unattractive solution to obtain homozygous mutants and improving the rates of perfect HDR in founder (F0) fish is thus required. Genome editing can represent small DNA changes down to single nucleotide replacements (SNR). This enables edits such as premature stop codons or single amino acid changes and may be used to obtain fish with traits favorable to aquaculture, e.g. disease resistance. A method for SNR has not yet been demonstrated in salmon. Results Using CRISPR/Cas9 and asymmetrical ODNs, we were able to perform precise SNR and introduce a premature stop codon in dnd in F0 salmon. Deep sequencing demonstrated up to 59.2% efficiency in single embryos. In addition, using the same asymmetrical ODN design, we inserted a FLAG element into slc45a2 and dnd, showing high individual perfect HDR efficiencies (up to 36.7 and 32.7%, respectively). Conclusions In this work, we demonstrate that precise SNR and knock-in (KI) can be performed in F0 salmon embryos using asymmetrical oligonucleotide (ODN) donors. We suggest that HDR-induced SNR can be applied as a powerful NBT, allowing efficient introgression of favorable alleles and bypassing challenges associated with traditional selective breeding. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07823-8.
Collapse
Affiliation(s)
- Anne Hege Straume
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Erik Kjærner-Semb
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kai Ove Skaftnesmo
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Hilal Güralp
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Simon Lillico
- The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | | |
Collapse
|
5
|
Skaftnesmo KO, Crespo D, Kleppe L, Andersson E, Edvardsen RB, Norberg B, Fjelldal PG, Hansen TJ, Schulz RW, Wargelius A. Loss of stra8 Increases Germ Cell Apoptosis but Is Still Compatible With Sperm Production in Atlantic Salmon ( Salmo salar). Front Cell Dev Biol 2021; 9:657192. [PMID: 33942021 PMCID: PMC8087537 DOI: 10.3389/fcell.2021.657192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/29/2021] [Indexed: 12/03/2022] Open
Abstract
Entering meiosis strictly depends on stimulated by retinoic acid 8 (Stra8) gene function in mammals. This gene is missing in a number of fish species, including medaka and zebrafish, but is present in the majority of fishes, including Atlantic salmon. Here, we have examined the effects of removing stra8 on male fertility in Atlantic salmon. As in mammals, stra8 expression was restricted to germ cells in the testis, transcript levels increased during the start of puberty, and decreased when blocking the production of retinoic acid. We targeted the salmon stra8 gene with two gRNAs one of these were highly effective and produced numerous mutations in stra8, which led to a loss of wild-type (WT) stra8 expression in F0 salmon testis. In maturing stra8 crispants, the spermatogenetic tubuli were partially disorganized and displayed a sevenfold increase in germ cell apoptosis, in particular among type B spermatogonia and spermatocytes. The production of spermatogenic cysts, on the other hand, increased in maturing stra8 crispants. Gene expression analysis revealed unchanged (lin28a, ret) or reduced levels (egr1, dusp4) of transcripts associated with undifferentiated spermatogonia. Decreased expression was recorded for some genes expressed in differentiating spermatogonia including dmrt1 and ccnd2 or in spermatocytes, such as ccna1. Different from Stra8-deficient mammals, a large number of germ cells completed spermatogenesis, sperm was produced and fertilization rates were similar in WT and crispant males. While loss of stra8 increased germ cell apoptosis during salmon spermatogenesis, crispants compensated this cell loss by an elevated production of spermatogenic cysts, and were able to produce functional sperm. It appears that also in a fish species with a stra8 gene in the genome, the critical relevance this gene has attained for mammalian spermatogenesis is not yet given, although detrimental effects of the loss of stra8 were clearly visible during maturation.
Collapse
Affiliation(s)
- Kai O Skaftnesmo
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway
| | - Diego Crespo
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway
| | - Lene Kleppe
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway
| | - Eva Andersson
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway
| | - Birgitta Norberg
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Austevoll Research Station, Storebø, Norway
| | - Per Gunnar Fjelldal
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Matre Research Station, Matredal, Norway
| | - Tom J Hansen
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Matre Research Station, Matredal, Norway
| | - Rüdiger W Schulz
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway.,Reproductive Biology Group, Division Developmental Biology, Department Biology, Science Faculty, Utrecht University, Utrecht, Netherlands
| | - Anna Wargelius
- Institute of Marine Research, Research Group Reproduction and Developmental Biology, Bergen, Norway
| |
Collapse
|
6
|
Feron R, Pan Q, Wen M, Imarazene B, Jouanno E, Anderson J, Herpin A, Journot L, Parrinello H, Klopp C, Kottler VA, Roco AS, Du K, Kneitz S, Adolfi M, Wilson CA, McCluskey B, Amores A, Desvignes T, Goetz FW, Takanashi A, Kawaguchi M, Detrich HW, Oliveira MA, Nóbrega RH, Sakamoto T, Nakamoto M, Wargelius A, Karlsen Ø, Wang Z, Stöck M, Waterhouse RM, Braasch I, Postlethwait JH, Schartl M, Guiguen Y. RADSex: A computational workflow to study sex determination using restriction site-associated DNA sequencing data. Mol Ecol Resour 2021; 21:1715-1731. [PMID: 33590960 DOI: 10.1111/1755-0998.13360] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/13/2022]
Abstract
The study of sex determination and sex chromosome organization in nonmodel species has long been technically challenging, but new sequencing methodologies now enable precise and high-throughput identification of sex-specific genomic sequences. In particular, restriction site-associated DNA sequencing (RAD-Seq) is being extensively applied to explore sex determination systems in many plant and animal species. However, software specifically designed to search for and visualize sex-biased markers using RAD-Seq data is lacking. Here, we present RADSex, a computational analysis workflow designed to study the genetic basis of sex determination using RAD-Seq data. RADSex is simple to use, requires few computational resources, makes no prior assumptions about the type of sex-determination system or structure of the sex locus, and offers convenient visualization through a dedicated R package. To demonstrate the functionality of RADSex, we re-analysed a published data set of Japanese medaka, Oryzias latipes, where we uncovered a previously unknown Y chromosome polymorphism. We then used RADSex to analyse new RAD-Seq data sets from 15 fish species spanning multiple taxonomic orders. We identified the sex determination system and sex-specific markers in six of these species, five of which had no known sex-markers prior to this study. We show that RADSex greatly facilitates the study of sex determination systems in nonmodel species thanks to its speed of analyses, low resource usage, ease of application and visualization options. Furthermore, our analysis of new data sets from 15 species provides new insights on sex determination in fish.
Collapse
Affiliation(s)
- Romain Feron
- INRAE, LPGP, Rennes, France.,Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Qiaowei Pan
- INRAE, LPGP, Rennes, France.,Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Ming Wen
- INRAE, LPGP, Rennes, France.,State Key Laboratory of Developmental Biology of Freshwater Fish, College of Life Science, Hunan Normal University, Changsha, China
| | | | | | - Jennifer Anderson
- INRAE, LPGP, Rennes, France.,Department of Organismal Biology, Systematic Biology, Uppsala University, Uppsala, Sweden
| | | | - Laurent Journot
- Institut de Génomique Fonctionnelle, IGF, CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Hugues Parrinello
- Institut de Génomique Fonctionnelle, IGF, CNRS, INSERM, Univ. Montpellier, Montpellier, France
| | - Christophe Klopp
- SIGENAE, Mathématiques et Informatique Appliquées de Toulouse, INRAE, Castanet Tolosan, France
| | - Verena A Kottler
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Alvaro S Roco
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Kang Du
- Department of Chemistry and Biochemistry, The Xiphophorus Genetic Stock Center, Texas State University, San Marcos, TX, USA.,Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Susanne Kneitz
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Mateus Adolfi
- Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | | | | | - Angel Amores
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | - Thomas Desvignes
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | - Frederick W Goetz
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, USA
| | - Ato Takanashi
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo, Japan
| | - Mari Kawaguchi
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Tokyo, Japan
| | - Harry William Detrich
- Department of Marine and Environmental Sciences, Marine Science Center, Northeastern University, Nahant, MA, USA
| | - Marcos A Oliveira
- Reproductive and Molecular Biology Group, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, Brazil
| | - Rafael H Nóbrega
- Reproductive and Molecular Biology Group, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, Brazil
| | - Takashi Sakamoto
- Department of Aquatic Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Masatoshi Nakamoto
- Department of Aquatic Marine Biosciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | | | | | - Zhongwei Wang
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany.,Institute of Hydrobiology, Chinese Academy of Sciences, Beijing, China
| | - Matthias Stöck
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Berlin, Germany
| | - Robert M Waterhouse
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Ingo Braasch
- Department of Integrative Biology, Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI, USA
| | | | - Manfred Schartl
- Department of Chemistry and Biochemistry, The Xiphophorus Genetic Stock Center, Texas State University, San Marcos, TX, USA.,Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | | |
Collapse
|
7
|
Kjærner‐Semb E, Edvardsen RB, Ayllon F, Vogelsang P, Furmanek T, Rubin CJ, Veselov AE, Nilsen TO, McCormick SD, Primmer CR, Wargelius A. Comparison of anadromous and landlocked Atlantic salmon genomes reveals signatures of parallel and relaxed selection across the Northern Hemisphere. Evol Appl 2021; 14:446-461. [PMID: 33664787 PMCID: PMC7896726 DOI: 10.1111/eva.13129] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 12/21/2022] Open
Abstract
Most Atlantic salmon (Salmo salar L.) populations follow an anadromous life cycle, spending early life in freshwater, migrating to the sea for feeding, and returning to rivers to spawn. At the end of the last ice age ~10,000 years ago, several populations of Atlantic salmon became landlocked. Comparing their genomes to their anadromous counterparts can help identify genetic variation related to either freshwater residency or anadromy. The objective of this study was to identify consistently divergent loci between anadromous and landlocked Atlantic salmon strains throughout their geographical distribution, with the long-term aim of identifying traits relevant for salmon aquaculture, including fresh and seawater growth, omega-3 metabolism, smoltification, and disease resistance. We used a Pool-seq approach (n = 10-40 individuals per population) to sequence the genomes of twelve anadromous and six landlocked Atlantic salmon populations covering a large part of the Northern Hemisphere and conducted a genomewide association study to identify genomic regions having been under different selection pressure in landlocked and anadromous strains. A total of 28 genomic regions were identified and included cadm1 on Chr 13 and ppargc1a on Chr 18. Seven of the regions additionally displayed consistently reduced heterozygosity in fish obtained from landlocked populations, including the genes gpr132, cdca4, and sertad2 on Chr 15. We also found 16 regions, including igf1 on Chr 17, which consistently display reduced heterozygosity in the anadromous populations compared to the freshwater populations, indicating relaxed selection on traits associated with anadromy in landlocked salmon. In conclusion, we have identified 37 regions which may harbor genetic variation relevant for improving fish welfare and quality in the salmon farming industry and for understanding life-history traits in fish.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Alexey E. Veselov
- Institute of Biology of the Karelian Research CentrePetrozavodskRussia
| | - Tom Ole Nilsen
- Department of Biological SciencesUniversity of BergenBergenNorway
| | - Stephen D. McCormick
- Conte Anadromous Fish Research LaboratoryU.S. Geological Survey, Leetown Science CenterTurners FallsMAUSA
| | - Craig R. Primmer
- Organismal and Evolutionary Biology Research ProgramFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | | |
Collapse
|
8
|
Jin Y, Datsomor AK, Olsen RE, Vik JO, Torgersen JS, Edvardsen RB, Wargelius A, Winge P, Grammes F. Targeted mutagenesis of ∆5 and ∆6 fatty acyl desaturases induce dysregulation of lipid metabolism in Atlantic salmon (Salmo salar). BMC Genomics 2020; 21:805. [PMID: 33213387 PMCID: PMC7678299 DOI: 10.1186/s12864-020-07218-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023] Open
Abstract
Background With declining wild fish populations, farmed salmon has gained popularity as a source for healthy long-chain highly unsaturated fatty acids (LC-HUFA). However, the introduction of plant oil in farmed salmon feeds has reduced the content of these beneficial LC-HUFA. The synthetic capability for LC-HUFAs depends upon the dietary precursor fatty acids and the genetic potential, thus there is a need for in-depth understanding of LC-HUFA synthetic genes and their interactions with other genes involved in lipid metabolism. Several key genes of LC-HUFA synthesis in salmon belong to the fatty acid desaturases 2 (fads2) family. The present study applied whole transcriptome analysis on two CRISPR-mutated salmon strains (crispants), 1) Δ6abc/5Mt with mutations in Δ5fads2, Δ6fads2-a, Δ6fads2-b and Δ6fads2-c genes, and 2) Δ6bcMt with mutations in Δ6fads2-b and Δ6fads2-c genes. Our purpose is to evaluate the genetic effect fads2 mutations have on other lipid metabolism pathways in fish, as well as to investigate mosaicism in a commercial species with a very long embryonal period. Results Both Δ6abc/5Mt and Δ6bcMt crispants demonstrated high percentage of indels within all intended target genes, though different indel types and percentage were observed between individuals. The Δ6abc/5Mt fish displayed several disruptive indels which resulted in over 100 differentially expressed genes (DEGs) enriched in lipid metabolism pathways in liver. This includes up-regulation of srebp1 genes which are known key transcription regulators of lipid metabolism as well as a number of down-stream genes involved in fatty acid de-novo synthesis, fatty acid β-oxidation and lipogenesis. Both elovl5 and elovl2 genes were not changed, suggesting that the genes were not targeted by Srebp1. The mutation of Δ6bcMt surprisingly resulted in over 3000 DEGs which were enriched in factors encoding genes involved in mRNA regulation and stability. Conclusions CRISPR-Cas9 can efficiently mutate multiple fads2 genes simultaneously in salmon. The results of the present study have provided new information on the transcriptional regulations of lipid metabolism genes after reduction of LC-HUFA synthesis pathways in salmon. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07218-1.
Collapse
Affiliation(s)
- Yang Jin
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, N-1432, Aas, Norway
| | - Alex K Datsomor
- Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Rolf E Olsen
- Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Jon Olav Vik
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432, Aas, Norway
| | | | | | | | - Per Winge
- Department of Biology, Norwegian University of Science and Technology, N-7491, Trondheim, Norway
| | - Fabian Grammes
- Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, N-1432, Aas, Norway. .,AquaGen AS, Post box 1240, Torgard, N-7462, Trondheim, Norway.
| |
Collapse
|
9
|
Fjelldal PG, Hansen TJ, Wargelius A, Ayllon F, Glover KA, Schulz RW, Fraser TWK. Development of supermale and all-male Atlantic salmon to research the vgll3 allele - puberty link. BMC Genet 2020; 21:123. [PMID: 33183224 PMCID: PMC7664053 DOI: 10.1186/s12863-020-00927-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/27/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Farmed Atlantic salmon are one of the most economically significant global aquaculture products. Early sexual maturation of farmed males represents a significant challenge to this industry and has been linked with the vgll3 genotype. However, tools to aid research of this topic, such as all-male and clonal fish, are still lacking. The present 6-year study examined if all-male production is possible in Atlantic salmon, a species with heteromorphic sex chromosomes (males being XY, females XX), and if all-male fish can be applied to further explore the vgll3 contribution on the likelihood of early maturation. RESULTS Estrogen treatment of mixed sex yolk sac larvae gave rise to one sexually mature hermaphrodite with a male genotype (XY) that was used to produce both self-fertilized offspring and androgenetic double haploid (dh) offspring following egg activation with UV treated sperm and pressure shock to block the first mitotic division. There were YY supermales among both offspring types, which were crossed with dh females. Between 1 and 8% of the putative all-male offspring from the eight crosses with self-fertilized supermales were found to have ovaries, and 95% of these phenotypic females were also genetically female. None of the offspring from the one dh supermale cross had ovaries. When assessing the general contribution of the vgll3 locus on the likelihood of early post-smolt sexual maturation (jacking) in the all-male populations we found individuals that were homozygous for the early maturing genotype (97%) were more likely to enter puberty than individuals that were homozygous for the late maturing genotype (26%). However, the likelihood of jacking within individuals with an early/late heterozygous genotype was higher when the early allele came from the dam (94%) compared to the sire (45%). CONCLUSIONS The present results show that supermale Atlantic salmon are viable and fertile and can be used as a research tool to study important aspects of sexual maturation, such as to further explore the sex dependent parental genetic contribution to age at puberty in Atlantic salmon. In addition, we report the production of viable double haploid supermale fish.
Collapse
Affiliation(s)
- Per Gunnar Fjelldal
- Institute of Marine Research (IMR), Matre Aquaculture Research Station, 5984 Matredal, Norway
| | - Tom J. Hansen
- Institute of Marine Research (IMR), Matre Aquaculture Research Station, 5984 Matredal, Norway
| | - Anna Wargelius
- Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| | - Fernando Ayllon
- Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| | - Kevin A. Glover
- Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| | - Rüdiger W. Schulz
- Reproductive Biology Group, Division Developmental Biology, Department of Biology, Faculty of Sciences, Utrecht University, Utrecht, The Netherlands
| | - Thomas W. K. Fraser
- Institute of Marine Research (IMR), Matre Aquaculture Research Station, 5984 Matredal, Norway
| |
Collapse
|
10
|
Ayllon F, Solberg MF, Besnier F, Fjelldal PG, Hansen TJ, Wargelius A, Edvardsen RB, Glover KA. Autosomal sdY Pseudogenes Explain Discordances Between Phenotypic Sex and DNA Marker for Sex Identification in Atlantic Salmon. Front Genet 2020; 11:544207. [PMID: 33173531 PMCID: PMC7591749 DOI: 10.3389/fgene.2020.544207] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 09/17/2020] [Indexed: 11/13/2022] Open
Abstract
Despite the key role that sex-determination plays in evolutionary processes, it is still poorly understood in many species. In salmonids, which are among the best studied fishes, the master sex-determining gene sexually dimorphic on the Y-chromosome (sdY) has been identified. However, sdY displays unexplained discordance to the phenotypic sex, with a variable frequency of phenotypic females being reported as genetic males. Multiple sex determining loci in Atlantic salmon have also been reported, possibly as a result of recent transposition events in this species. We hypothesized the existence of an autosomal copy of sdY, causing apparent discordance between phenotypic and genetic sex, that is transmitted in accordance with autosomal inheritance. To test this, we developed a qPCR methodology to detect the total number of sdY copies present in the genome. Based on the observed phenotype/genotype frequencies and linkage analysis among 2,025 offspring from 64 pedigree-controlled families of accurately phenotyped Atlantic salmon, we identified both males and females carrying one or two autosomal copies of sdY in addition to the Y-specific copy present in males. Patterns across families were highly consistent with autosomal inheritance. These autosomal sdY copies appear to have lost the ability to function as a sex determining gene and were only occasionally assigned to the actual sex chromosome in any of the affected families.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Kevin Alan Glover
- Institute of Marine Research, Bergen, Norway.,Department of Biological Sciences, University of Bergen, Bergen, Norway
| |
Collapse
|
11
|
Kleppe L, Edvardsen RB, Furmanek T, Andersson E, Skaftnesmo KO, Thyri Segafredo F, Wargelius A. Transcriptomic analysis of dead end knockout testis reveals germ cell and gonadal somatic factors in Atlantic salmon. BMC Genomics 2020; 21:99. [PMID: 32000659 PMCID: PMC6993523 DOI: 10.1186/s12864-020-6513-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 01/20/2020] [Indexed: 02/06/2023] Open
Abstract
Background Sustainability challenges are currently hampering an increase in salmon production. Using sterile salmon can solve problems with precocious puberty and genetic introgression from farmed escapees to wild populations. Recently sterile salmon was produced by knocking out the germ cell-specific dead end (dnd). Several approaches may be applied to inhibit Dnd function, including gene knockout, knockdown or immunization. Since it is challenging to develop a successful treatment against a gene product already existing in the body, alternative targets are being explored. Germ cells are surrounded by, and dependent on, gonadal somatic cells. Targeting genes essential for the survival of gonadal somatic cells may be good alternative targets for sterility treatments. Our aim was to identify and characterize novel germ cell and gonadal somatic factors in Atlantic salmon. Results We have for the first time analysed RNA-sequencing data from germ cell-free (GCF)/dnd knockout and wild type (WT) salmon testis and searched for genes preferentially expressed in either germ cells or gonadal somatic cells. To exclude genes with extra-gonadal expression, our dataset was merged with available multi-tissue transcriptome data. We identified 389 gonad specific genes, of which 194 were preferentially expressed within germ cells, and 11 were confined to gonadal somatic cells. Interestingly, 5 of the 11 gonadal somatic transcripts represented genes encoding secreted TGF-β factors; gsdf, inha, nodal and two bmp6-like genes, all representative vaccine targets. Of these, gsdf and inha had the highest transcript levels. Expression of gsdf and inha was further confirmed to be gonad specific, and their spatial expression was restricted to granulosa and Sertoli cells of the ovary and testis, respectively. Finally, we show that inha expression increases with puberty in both ovary and testis tissue, while gsdf expression does not change or decreases during puberty in ovary and testis tissue, respectively. Conclusions This study contributes with transcriptome data on salmon testis tissue with and without germ cells. We provide a list of novel and known germ cell- and gonad somatic specific transcripts, and show that the expression of two highly active gonadal somatic secreted TGF-β factors, gsdf and inha, are located within granulosa and Sertoli cells.
Collapse
Affiliation(s)
- Lene Kleppe
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| | | | - Tomasz Furmanek
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Eva Andersson
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kai Ove Skaftnesmo
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | | | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| |
Collapse
|
12
|
Straume AH, Kjærner-Semb E, Ove Skaftnesmo K, Güralp H, Kleppe L, Wargelius A, Edvardsen RB. Indel locations are determined by template polarity in highly efficient in vivo CRISPR/Cas9-mediated HDR in Atlantic salmon. Sci Rep 2020; 10:409. [PMID: 31941961 PMCID: PMC6962318 DOI: 10.1038/s41598-019-57295-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 12/19/2019] [Indexed: 01/20/2023] Open
Abstract
Precise gene editing such as CRISPR/Cas9-mediated homology directed repair (HDR) can increase our understanding of gene function and improve traits of importance for aquaculture. This fine-tuned technology has not been developed for farmed fish including Atlantic salmon. We performed knock-in (KI) of a FLAG element in the slc45a2 gene in salmon using sense (S), anti-sense (AS) and double-stranded (ds) oligodeoxynucleotide (ODN) templates with short (24/48/84 bp) homology arms. We show in vivo ODN integration in almost all the gene edited animals, and demonstrate perfect HDR rates up to 27% in individual F0 embryos, much higher than reported previously in any fish. HDR efficiency was dependent on template concentration, but not homology arm length. Analysis of imperfect HDR variants suggest that repair occurs by synthesis-dependent strand annealing (SDSA), as we show for the first time in any species that indel location is dependent on template polarity. Correct ODN polarity can be used to avoid 5'-indels interrupting the reading frame of an inserted sequence and be of importance for HDR template design in general.
Collapse
Affiliation(s)
- Anne Hege Straume
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Erik Kjærner-Semb
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kai Ove Skaftnesmo
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Hilal Güralp
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Lene Kleppe
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | | |
Collapse
|
13
|
Gratacap RL, Wargelius A, Edvardsen RB, Houston RD. Potential of Genome Editing to Improve Aquaculture Breeding and Production. Trends Genet 2019; 35:672-684. [PMID: 31331664 DOI: 10.1016/j.tig.2019.06.006] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/21/2019] [Accepted: 06/26/2019] [Indexed: 02/02/2023]
Abstract
Aquaculture is the fastest growing food production sector and is rapidly becoming the primary source of seafood for human diets. Selective breeding programs are enabling genetic improvement of production traits, such as disease resistance, but progress is limited by the heritability of the trait and generation interval of the species. New breeding technologies, such as genome editing using CRISPR/Cas9 have the potential to expedite sustainable genetic improvement in aquaculture. Genome editing can rapidly introduce favorable changes to the genome, such as fixing alleles at existing trait loci, creating de novo alleles, or introducing alleles from other strains or species. The high fecundity and external fertilization of most aquaculture species can facilitate genome editing for research and application at a scale that is not possible in farmed terrestrial animals.
Collapse
Affiliation(s)
- Remi L Gratacap
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK
| | - Anna Wargelius
- Institute of Marine Research, PO Box 1870, Nordnes, NO-5817 Bergen, Norway
| | | | - Ross D Houston
- The Roslin Institute, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK.
| |
Collapse
|
14
|
Ayllon F, Solberg MF, Glover KA, Mohammadi F, Kjærner-Semb E, Fjelldal PG, Andersson E, Hansen T, Edvardsen RB, Wargelius A. The influence of vgll3 genotypes on sea age at maturity is altered in farmed mowi strain Atlantic salmon. BMC Genet 2019; 20:44. [PMID: 31060499 PMCID: PMC6501413 DOI: 10.1186/s12863-019-0745-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/25/2019] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND In Atlantic salmon in the wild, age at maturity is strongly influenced by the vgll3 locus. Under farming conditions, light, temperature and feeding regimes are known significantly advance or delay age at maturity. However, the potential influence of the vgll3 locus on the maturation of salmon reared under farming conditions has been rarely investigated, especially in females. RESULTS Here, we reared domesticated salmon (mowi strain) with different vgll3 genotypes under standard farming conditions until they matured at either one, two or more than two sea winters. Interestingly, and in contrast to previous findings in the wild, we were not able to identify a link between vgll3 and age at maturity in females when reared under farming conditions. For males however, we found that the probability of delaying maturation from one to two sea winters was significantly lower in fish homozygous for the early allele compared to homozygous fish for the late allele, while the probability for heterozygous fish was intermediate. These data also contrast to previous findings in the wild where the early allele has been reported as dominant. However, we found that the probability of males delaying maturation from two to three sea winters was regulated in the same manner as the wild. CONCLUSIONS Collectively, our data suggest that increased growth rates in mowi salmon, caused by high feed intake and artificial light and temperature regimes together with other possible genetic/epigenetic components, may significantly influence the impact that the vgll3 locus has on age at maturity, especially in females. In turn, our results show that the vgll3 locus can only to a large extent be used in selective breeding to control age at maturation in mowi males. In summary, we here show that in contrast to the situation in wild salmon, under farming conditions vgll3 does not seem to influence age at maturity in mowi females whereas in mowi males, maturing as one or two sea winters it alters the early allele effect from dominant to intermediate.
Collapse
Affiliation(s)
- Fernando Ayllon
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Monica F Solberg
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kevin A Glover
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Institute of Biology, University of Bergen, Bergen, Norway
| | - Faezeh Mohammadi
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Erik Kjærner-Semb
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Per Gunnar Fjelldal
- Institute of Marine research (IMR), Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Eva Andersson
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Tom Hansen
- Institute of Marine research (IMR), Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| |
Collapse
|
15
|
Bui S, Dalvin S, Dempster T, Skulstad OF, Edvardsen RB, Wargelius A, Oppedal F. Susceptibility, behaviour, and retention of the parasitic salmon louse (Lepeophtheirus salmonis) differ with Atlantic salmon population origin. J Fish Dis 2018; 41:431-442. [PMID: 28921589 DOI: 10.1111/jfd.12707] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 07/18/2017] [Accepted: 07/25/2017] [Indexed: 06/07/2023]
Abstract
Atlantic salmon populations across the world have diverse ecological and evolutionary histories, from wild anadromous or landlocked, to domestication and genetic modification. The natural host behaviours confer protection from infestation by ectoparasitic salmon lice Lepeophtheirus salmonis, yet whether genetic origin results in different behaviours and thus susceptibility to infestation is unknown. In common garden experiments, we tested antiparasite behaviours, susceptibility and retention of salmon lice in wild anadromous, wild landlocked, domesticated and genetically modified domesticated strains. Within domesticated strains, we tested two infestation histories (previously infested and naïve) and a new phenotype (albino colouring). Farmed stocks initially acquired 24%-44% higher levels of parasite density than the wild and landlocked strains. Burst swimming and displacement behaviours were higher in the domesticated groups, and jumping was more prevalent in the domesticated strains. At 34 days post-infestation, domesticated strains and the wild anadromous strain did not differ significantly from each other; however, landlocked salmon had increased infestation levels considerably. Domesticated strains lost ~20% (±9.9%-16.5%; 95% CI) of their initial parasite load, while parasite load increased by 5.5% (±30.1%) for wild salmon and 20.1% (±28.5%) in landlocked salmon. This study provides early evidence for diverged host-parasite interactions associated with domestication in this system.
Collapse
Affiliation(s)
- S Bui
- Sustainable Aquaculture Laboratory - Temperate and Tropical (SALTT), School of BioSciences, University of Melbourne, Parkville, Vic, Australia
- Institute of Marine Research, Bergen, Norway
| | - S Dalvin
- Institute of Marine Research, Bergen, Norway
| | - T Dempster
- Sustainable Aquaculture Laboratory - Temperate and Tropical (SALTT), School of BioSciences, University of Melbourne, Parkville, Vic, Australia
- Institute of Marine Research, Bergen, Norway
| | | | | | - A Wargelius
- Institute of Marine Research, Bergen, Norway
| | - F Oppedal
- Institute of Marine Research, Bergen, Norway
| |
Collapse
|
16
|
Kjærner-Semb E, Ayllon F, Kleppe L, Sørhus E, Skaftnesmo K, Furmanek T, Segafredo FT, Thorsen A, Fjelldal PG, Hansen T, Taranger GL, Andersson E, Schulz RW, Wargelius A, Edvardsen RB. Vgll3 and the Hippo pathway are regulated in Sertoli cells upon entry and during puberty in Atlantic salmon testis. Sci Rep 2018; 8:1912. [PMID: 29382956 PMCID: PMC5789820 DOI: 10.1038/s41598-018-20308-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/16/2018] [Indexed: 01/07/2023] Open
Abstract
Vgll3 is linked to age at maturity in Atlantic salmon (Salmo salar). However, the molecular mechanisms involving Vgll3 in controlling timing of puberty as well as relevant tissue and cell types are currently unknown. Vgll3 and the associated Hippo pathway has been linked to reduced proliferation activity in different tissues. Analysis of gene expression reveals for the first time that vgll3 and several members of the Hippo pathway were down-regulated in salmon testis during onset of puberty and remained repressed in maturing testis. In the gonads, we found expression in Sertoli and granulosa cells in males and females, respectively. We hypothesize that vgll3 negatively regulates Sertoli cell proliferation in testis and therefore acts as an inhibitor of pubertal testis growth. Gonadal expression of vgll3 is located to somatic cells that are in direct contact with germ cells in both sexes, however our results indicate sex-biased regulation of vgll3 during puberty.
Collapse
Affiliation(s)
- Erik Kjærner-Semb
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway. .,Department of Biology, University of Bergen, Bergen, Norway.
| | - Fernando Ayllon
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Lene Kleppe
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Elin Sørhus
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kai Skaftnesmo
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Tomasz Furmanek
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Frida T Segafredo
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Anders Thorsen
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Per Gunnar Fjelldal
- Institute of Marine research, Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Tom Hansen
- Institute of Marine research, Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Geir Lasse Taranger
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Eva Andersson
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Rüdiger W Schulz
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Department Biology, Utrecht University, Science Faculty, Padualaan 8, NL-3584 CH, Utrecht, The Netherlands
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| |
Collapse
|
17
|
Skaftnesmo KO, Edvardsen RB, Furmanek T, Crespo D, Andersson E, Kleppe L, Taranger GL, Bogerd J, Schulz RW, Wargelius A. Integrative testis transcriptome analysis reveals differentially expressed miRNAs and their mRNA targets during early puberty in Atlantic salmon. BMC Genomics 2017; 18:801. [PMID: 29047327 PMCID: PMC5648517 DOI: 10.1186/s12864-017-4205-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/09/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Our understanding of the molecular mechanisms implementing pubertal maturation of the testis in vertebrates is incomplete. This topic is relevant in Atlantic salmon aquaculture, since precocious male puberty negatively impacts animal welfare and growth. We hypothesize that certain miRNAs modulate mRNAs relevant for the initiation of puberty. To explore which miRNAs regulate mRNAs during initiation of puberty in salmon, we performed an integrated transcriptome analysis (miRNA and mRNA-seq) of salmon testis at three stages of development: an immature, long-term quiescent stage, a prepubertal stage just before, and a pubertal stage just after the onset of single cell proliferation activity in the testis. RESULTS Differentially expressed miRNAs clustered into 5 distinct expression profiles related to the immature, prepubertal and pubertal salmon testis. Potential mRNA targets of these miRNAs were predicted with miRmap and filtered for mRNAs displaying negatively correlated expression patterns. In summary, this analysis revealed miRNAs previously known to be regulated in immature vertebrate testis (miR-101, miR-137, miR-92b, miR-18a, miR-20a), but also miRNAs first reported here as regulated in the testis (miR-new289, miR-30c, miR-724, miR-26b, miR-new271, miR-217, miR-216a, miR-135a, miR-new194 and the novel predicted n268). By KEGG enrichment analysis, progesterone signaling and cell cycle pathway genes were found regulated by these differentially expressed miRNAs. During the transition into puberty we found differential expression of miRNAs previously associated (let7a/b/c), or newly associated (miR-15c, miR-2184, miR-145 and the novel predicted n7a and b) with this stage. KEGG enrichment analysis revealed that mRNAs of the Wnt, Hedgehog and Apelin signaling pathways were potential regulated targets during the transition into puberty. Likewise, several regulated miRNAs in the pubertal stage had earlier been associated (miR-20a, miR-25, miR-181a, miR-202, let7c/d/a, miR-125b, miR-222a/b, miR-190a) or have now been found connected (miR-2188, miR-144, miR-731, miR-8157 and the novel n2) to the initiation of puberty. CONCLUSIONS This study has - for the first time - linked testis maturation to specific miRNAs and their inversely correlated expressed targets in Atlantic salmon. The study indicates a broad functional conservation of already known miRNAs and associated pathways involved in the transition into puberty in vertebrates. The analysis also reveals miRNAs not previously associated with testis tissue or its maturation, which calls for further functional studies in the testis.
Collapse
Affiliation(s)
- K O Skaftnesmo
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway.
| | - R B Edvardsen
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway
| | - T Furmanek
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway
| | - D Crespo
- Reproductive Biology group, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - E Andersson
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway
| | - L Kleppe
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway
| | - G L Taranger
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway
| | - J Bogerd
- Reproductive Biology group, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - R W Schulz
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway.,Reproductive Biology group, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - A Wargelius
- Institute of Marine Research, Postboks 1870 Nordnes, 5817, Bergen, Norway
| |
Collapse
|
18
|
Kleppe L, Andersson E, Skaftnesmo KO, Edvardsen RB, Fjelldal PG, Norberg B, Bogerd J, Schulz RW, Wargelius A. Sex steroid production associated with puberty is absent in germ cell-free salmon. Sci Rep 2017; 7:12584. [PMID: 28974703 PMCID: PMC5626747 DOI: 10.1038/s41598-017-12936-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/20/2017] [Indexed: 11/09/2022] Open
Abstract
In all vertebrates studied so far, germ cells are not required for pubertal maturation of the gonadal steroidogenic system, subsequent development of secondary sex characteristics and reproductive behavior. To explore if the absence of germ cells affects puberty or growth in Atlantic salmon, germ cell-free (GCF), dnd knockout and wild type (WT) postsmolts were stimulated to enter puberty. No GCF fish entered puberty, whereas 66.7% (males) and 30% (females) WT fish completed or entered puberty, respectively. Expression of genes related to steroidogenesis (star, cyp17a1, cyp11β, cyp19a1a), gonadal somatic cells (insl3, amh, igf3), oocytes (bmp15), gonadotropin receptors (fshr, lhcgr), and pituitary gonadotropic cells (fshb, lhb, gnrhr4) showed an immature status and failure to up-regulate gonadal sex steroid production in male and female GCF fish was also reflected in low or undetectable plasma sex steroids (11-ketotestosterone, estradiol-17β and testosterone). A gender difference (high in females, low in males) was found in the expression of star and cyp17a1 in GCF fish. No clear difference in growth was detected between GCF and immature WT fish, while growth was compromised in maturing WT males. We demonstrate for the first time in a vertebrate that germ cells are required for pubertal activation of the somatic steroidogenic cells.
Collapse
Affiliation(s)
- Lene Kleppe
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| | - Eva Andersson
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kai Ove Skaftnesmo
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Per Gunnar Fjelldal
- Institute of Marine Research, Matre Aquaculture Research Station, 5984, Matredal, Norway
| | - Birgitta Norberg
- Institute of Marine Research, Austevoll Research Station, 5392, Storebø, Norway
| | - Jan Bogerd
- Utrecht University, Faculty of Science, Department of Biology, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Rüdiger W Schulz
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Utrecht University, Faculty of Science, Department of Biology, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| |
Collapse
|
19
|
Macqueen DJ, Primmer CR, Houston RD, Nowak BF, Bernatchez L, Bergseth S, Davidson WS, Gallardo-Escárate C, Goldammer T, Guiguen Y, Iturra P, Kijas JW, Koop BF, Lien S, Maass A, Martin SAM, McGinnity P, Montecino M, Naish KA, Nichols KM, Ólafsson K, Omholt SW, Palti Y, Plastow GS, Rexroad CE, Rise ML, Ritchie RJ, Sandve SR, Schulte PM, Tello A, Vidal R, Vik JO, Wargelius A, Yáñez JM. Functional Annotation of All Salmonid Genomes (FAASG): an international initiative supporting future salmonid research, conservation and aquaculture. BMC Genomics 2017; 18:484. [PMID: 28655320 PMCID: PMC5488370 DOI: 10.1186/s12864-017-3862-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 06/14/2017] [Indexed: 11/21/2022] Open
Abstract
We describe an emerging initiative - the 'Functional Annotation of All Salmonid Genomes' (FAASG), which will leverage the extensive trait diversity that has evolved since a whole genome duplication event in the salmonid ancestor, to develop an integrative understanding of the functional genomic basis of phenotypic variation. The outcomes of FAASG will have diverse applications, ranging from improved understanding of genome evolution, to improving the efficiency and sustainability of aquaculture production, supporting the future of fundamental and applied research in an iconic fish lineage of major societal importance.
Collapse
Affiliation(s)
- Daniel J. Macqueen
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ UK
| | - Craig R. Primmer
- Department of Biology, University of Turku, 20014 Turku, Finland
| | - Ross D. Houston
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Midlothian, EH25 9RG UK
| | - Barbara F. Nowak
- Institute for Marine and Antarctic Studies, University of Tasmania, Launceston, TAS Australia
| | - Louis Bernatchez
- Département de biologie, Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, G1V 0A6 Canada
| | - Steinar Bergseth
- The Research Council of Norway, Drammensveien 288, P.O. Box 564, NO-1327 Lysaker, Norway
| | - William S. Davidson
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6 Canada
| | - Cristian Gallardo-Escárate
- Laboratory of Biotechnology and Aquatic Genomics, Interdisciplinary Center for Aquaculture Research, Department of Oceanography, Universidad de Concepción, 4030000 Concepción, Chile
| | - Tom Goldammer
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Fish Genetics Unit, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany
| | - Yann Guiguen
- INRA, UR1037 Fish Physiology and Genomics, Rennes, France
| | - Patricia Iturra
- Human Genetics Program ICBM Faculty of Medicine, University of Chile, Santiago, Chile
| | | | - Ben F. Koop
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5 Canada
| | - Sigbjørn Lien
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Alejandro Maass
- Center for Mathematical Modelling, Department of Mathematical Engineering, University of Chile, 8370456 Santiago, Chile
- Center for Genome Regulation, University of Chile, 8370456 Santiago, Chile
| | - Samuel A. M. Martin
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ UK
| | - Philip McGinnity
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Martin Montecino
- Center for Biomedical Research, Universidad Andres Bello, 8370146 Santiago, Chile
- FONDAP Center for Genome Regulation, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, 8370146 Santiago, Chile
| | - Kerry A. Naish
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195 USA
| | - Krista M. Nichols
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Blvd E, Seattle, WA 98112 USA
| | | | - Stig W. Omholt
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
- NTNU - Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Yniv Palti
- National Center for Cool and Cold Water Aquaculture, USDA ARS, 11861 Leetown Road, Kearneysville, WV 25430 USA
| | - Graham S. Plastow
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB Canada
| | - Caird E. Rexroad
- Office of National Programs, USDA ARS, 5601 Sunnyside Avenue, Beltsville, MD 20705-5148 USA
| | - Matthew L. Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, 1 Marine Lab Road, St. John’s, NL A1C 5S7 Canada
| | - Rachael J. Ritchie
- Genome British Columbia, Suite 400 – 575, West 8th Avenue, Vancouver, BC V5Z 0C4 Canada
| | - Simen R. Sandve
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Patricia M. Schulte
- Department of Zoology, University of British Columbia, 6270 University Blvd, Vancouver, BC V6T 1Z4 Canada
| | - Alfredo Tello
- Instituto Tecnológico del Salmón S.A., INTESAL de SalmonChile, Puerto Montt, Chile
| | - Rodrigo Vidal
- Laboratory of Molecular Ecology, Genomics, and Evolutionary Studies, Department of Biology, University of Santiago, 9170022 Santiago, Chile
| | - Jon Olav Vik
- Centre for Integrative Genetics (CIGENE), Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway
| | - Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817 Bergen, Norway
| | - José Manuel Yáñez
- Faculty of Veterinary and Animal Sciences, University of Chile, Av. Santa Rosa 11735, Santiago, Chile & Aquainnovo, Cardonal s/n, Puerto Montt, Chile
| |
Collapse
|
20
|
Reimer T, Dempster T, Wargelius A, Fjelldal PG, Hansen T, Glover KA, Solberg MF, Swearer SE. Rapid growth causes abnormal vaterite formation in farmed fish otoliths. J Exp Biol 2017; 220:2965-2969. [DOI: 10.1242/jeb.148056] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 06/01/2017] [Indexed: 01/06/2023]
Abstract
Sagittal otoliths are essential components of the sensory organs that enable all teleost fish to hear and maintain balance, and are primarily composed of calcium carbonate. A deformity, where aragonite (the normal crystal form) is replaced with vaterite, was first noted over 50 years ago but its underlying cause is unresolved. We evaluated the prevalence of vateritic otoliths from two captive rearing studies which suggested that fast growth, due to environmental rather than genetic control, led to vaterite development. We then tested this by varying light and temperature to create phenotypes with different growth rates, which resulted in fast growers (5x larger) having 3 times more vaterite than slow growers. A decrease in either the ratio of otolith matrix proteins (otolin-1/OMM-64) or [Ca2+]/[CO32–] may explain why fast growth causes vaterite deposition. As vaterite decreases hearing sensitivity, reducing growth rates in hatcheries may improve the welfare of farmed fish and increase the success of conservation efforts.
Collapse
Affiliation(s)
- T. Reimer
- School of BioSciences, University of Melbourne, Victoria 3010, Australia
| | - T. Dempster
- School of BioSciences, University of Melbourne, Victoria 3010, Australia
| | - A. Wargelius
- Section of Molecular Biology, Institute of Marine Research (IMR), Bergen, Norway
| | - P. G. Fjelldal
- Institute of Marine Research (IMR), Matre Research Station, 5984 Matredal, Norway
| | - T. Hansen
- Institute of Marine Research (IMR), Matre Research Station, 5984 Matredal, Norway
| | - K. A. Glover
- Population Genetics Research Group, Institute of Marine Research (IMR), Bergen, Norway
- Sea Lice Research Centre, Department of Biology, University of Bergen, Norway
| | - M. F. Solberg
- Population Genetics Research Group, Institute of Marine Research (IMR), Bergen, Norway
| | - S. E. Swearer
- School of BioSciences, University of Melbourne, Victoria 3010, Australia
| |
Collapse
|
21
|
Kleppe L, Edvardsen RB, Furmanek T, Andersson E, Juanchich A, Wargelius A. bmp15l,figla,smc1bl, andlarp6lare preferentially expressed in germ cells in Atlantic salmon (Salmo salarL.). Mol Reprod Dev 2016; 84:76-87. [DOI: 10.1002/mrd.22755] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/02/2016] [Indexed: 11/11/2022]
|
22
|
Kjærner-Semb E, Ayllon F, Furmanek T, Wennevik V, Dahle G, Niemelä E, Ozerov M, Vähä JP, Glover KA, Rubin CJ, Wargelius A, Edvardsen RB. Atlantic salmon populations reveal adaptive divergence of immune related genes - a duplicated genome under selection. BMC Genomics 2016; 17:610. [PMID: 27515098 PMCID: PMC4982270 DOI: 10.1186/s12864-016-2867-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 06/30/2016] [Indexed: 12/31/2022] Open
Abstract
Background Populations of Atlantic salmon display highly significant genetic differences with unresolved molecular basis. These differences may result from separate postglacial colonization patterns, diversifying natural selection and adaptation, or a combination. Adaptation could be influenced or even facilitated by the recent whole genome duplication in the salmonid lineage which resulted in a partly tetraploid species with duplicated genes and regions. Results In order to elucidate the genes and genomic regions underlying the genetic differences, we conducted a genome wide association study using whole genome resequencing data from eight populations from Northern and Southern Norway. From a total of ~4.5 million sequencing-derived SNPs, more than 10 % showed significant differentiation between populations from these two regions and ten selective sweeps on chromosomes 5, 10, 11, 13–15, 21, 24 and 25 were identified. These comprised 59 genes, of which 15 had one or more differentiated missense mutation. Our analysis showed that most sweeps have paralogous regions in the partially tetraploid genome, each lacking the high number of significant SNPs found in the sweeps. The most significant sweep was found on Chr 25 and carried several missense mutations in the antiviral mx genes, suggesting that these populations have experienced differing viral pressures. Interestingly the second most significant sweep, found on Chr 5, contains two genes involved in the NF-KB pathway (nkap and nkrf), which is also a known pathogen target that controls a large number of processes in animals. Conclusion Our results show that natural selection acting on immune related genes has contributed to genetic divergence between salmon populations in Norway. The differences between populations may have been facilitated by the plasticity of the salmon genome. The observed signatures of selection in duplicated genomic regions suggest that the recently duplicated genome has provided raw material for evolutionary adaptation. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2867-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Erik Kjærner-Semb
- Institute of Marine Research, Bergen, Norway. .,Department of Biology, University of Bergen, Bergen, Norway.
| | | | | | | | - Geir Dahle
- Institute of Marine Research, Bergen, Norway
| | - Eero Niemelä
- Natural Resources Institute Finland, Helsinki, Finland
| | - Mikhail Ozerov
- Kevo Subarctic Research Institute, University of Turku, Turku, Finland
| | - Juha-Pekka Vähä
- Kevo Subarctic Research Institute, University of Turku, Turku, Finland.,Association for Water and Environment of Western Uusimaa, Uusimaa, Finland
| | - Kevin A Glover
- Institute of Marine Research, Bergen, Norway.,Department of Biology, University of Bergen, Bergen, Norway
| | - Carl J Rubin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | | | | |
Collapse
|
23
|
Ayllon F, Kjærner-Semb E, Furmanek T, Wennevik V, Solberg MF, Dahle G, Taranger GL, Glover KA, Almén MS, Rubin CJ, Edvardsen RB, Wargelius A. The vgll3 Locus Controls Age at Maturity in Wild and Domesticated Atlantic Salmon (Salmo salar L.) Males. PLoS Genet 2015; 11:e1005628. [PMID: 26551894 PMCID: PMC4638356 DOI: 10.1371/journal.pgen.1005628] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 10/05/2015] [Indexed: 11/25/2022] Open
Abstract
Wild and domesticated Atlantic salmon males display large variation for sea age at sexual maturation, which varies between 1-5 years. Previous studies have uncovered a genetic predisposition for variation of age at maturity with moderate heritability, thus suggesting a polygenic or complex nature of this trait. The aim of this study was to identify associated genetic loci, genes and ultimately specific sequence variants conferring sea age at maturity in salmon. We performed a genome wide association study (GWAS) using a pool sequencing approach (20 individuals per river and phenotype) of male salmon returning to rivers as sexually mature either after one sea winter (2009) or three sea winters (2011) in six rivers in Norway. The study revealed one major selective sweep, which covered 76 significant SNPs in which 74 were found in a 370 kb region of chromosome 25. Genotyping other smolt year classes of wild and domesticated salmon confirmed this finding. Genotyping domesticated fish narrowed the haplotype region to four SNPs covering 2386 bp, containing the vgll3 gene, including two missense mutations explaining 33-36% phenotypic variation. A single locus was found to have a highly significant role in governing sea age at maturation in this species. The SNPs identified may be both used as markers to guide breeding for late maturity in salmon aquaculture and in monitoring programs of wild salmon. Interestingly, a SNP in proximity of the VGLL3 gene in humans (Homo sapiens), has previously been linked to age at puberty suggesting a conserved mechanism for timing of puberty in vertebrates.
Collapse
Affiliation(s)
| | - Erik Kjærner-Semb
- Institute of Marine Research, Bergen, Norway
- Department of Biology, University of Bergen, Bergen, Norway
| | | | | | | | - Geir Dahle
- Institute of Marine Research, Bergen, Norway
| | | | - Kevin A. Glover
- Institute of Marine Research, Bergen, Norway
- Department of Biology, University of Bergen, Bergen, Norway
| | - Markus Sällman Almén
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Carl J Rubin
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | | | | |
Collapse
|
24
|
Wargelius A, Furmanek T, Montfort J, Le Cam A, Kleppe L, Juanchich A, Edvardsen RB, Taranger GL, Bobe J. A comparison between egg trancriptomes of cod and salmon reveals species-specific traits in eggs for each species. Mol Reprod Dev 2015; 82:397-404. [PMID: 25908546 DOI: 10.1002/mrd.22487] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 04/02/2015] [Indexed: 12/20/2022]
Abstract
Fish in use in aquaculture display large variation in gamete biology. To reach better understanding around this issue, this study aims at identifying if species specific "egg life history traits" can be hidden in the unfertilized egg. This was done by investigating egg transcriptome differences between Atlantic salmon and Atlantic cod. Salmon and cod eggs were selected due to their largely differencing phenotypes. An oligo microarray analysis was performed on ovulated eggs from cod (n = 8) and salmon (n = 7). The arrays were normalized to a similar spectrum for both arrays. Both arrays were re-annotated with SWISS-Prot and KEGG genes to retrieve an official gene symbol and an orthologous KEGG annotation, in salmon and cod arrays this represented 14,009 and 7,437 genes respectively. The probe linked to the highest gene expression for that particular KEGG annotation was used to compare expression between species. Differential expression was calculated for genes that had an annotation with score >300, resulting in a total of 2,457 KEGG annotations (genes) being differently expressed between the species (FD > 2). This analysis revealed that immune, signal transduction and excretory related pathways were overrepresented in salmon compared to cod. The most overrepresented pathways in cod were related to regulation of genetic information processing and metabolism. To conclude this analysis clearly point at some distinct transcriptome repertoires for cod and salmon and that these differences may explain some of the species-specific biological features for salmon and cod eggs.
Collapse
Affiliation(s)
| | | | | | | | - Lene Kleppe
- Institute of Marine Research, Bergen, Norway
| | - Amelie Juanchich
- Institute of Marine Research, Bergen, Norway.,INRA, Campus de Beaulieu, Rennes, France
| | | | | | | |
Collapse
|
25
|
Kleppe L, Edvardsen RB, Furmanek T, Taranger GL, Wargelius A. Global transcriptome analysis identifies regulated transcripts and pathways activated during oogenesis and early embryogenesis in Atlantic cod. Mol Reprod Dev 2014; 81:619-35. [PMID: 24687555 PMCID: PMC4265210 DOI: 10.1002/mrd.22328] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 03/25/2014] [Indexed: 12/28/2022]
Abstract
The molecular mechanisms underlying oogenesis and maternally controlled embryogenesis in fish are not fully understood, especially in marine species. Our aim was to study the egg and embryo transcriptome during oogenesis and early embryogenesis in Atlantic cod. Follicles from oogenesis stages (pre-, early-, and late-vitellogenic), ovulated eggs, and two embryonic stages (blastula, gastrula) were collected from broodstock fish and fertilized eggs. Gene expression profiles were measured in a 44 K oligo microarray consisting of 23,000 cod genes. Hundreds of differentially expressed genes (DEGs) were identified in the follicle stages investigated, implicating a continuous accumulation and degradation of polyadenylated transcripts throughout oogenesis. Very few DEGs were identified from ovulated egg to blastula, showing a more stable maternal RNA pool in early embryonic stages. The highest induction of expression was observed between blastula and gastrula, signifying the onset of zygotic transcription. During early vitellogenesis, several of the most upregulated genes are linked to nervous system signaling, suggesting increasing requirements for ovarian synaptic signaling to stimulate the rapid growth of oocytes. Highly upregulated genes during late vitellogenesis are linked to protein processing, fat metabolism, osmoregulation, and arrested meiosis. One of the genes with the highest upregulation in the ovulated egg is involved in oxidative phosphorylation, reflecting increased energy requirements during fertilization and the first rapid cell divisions of early embryogenesis. In conclusion, this study provides a large-scale presentation of the Atlantic cod's maternally controlled transcriptome in ovarian follicles through oogenesis, ovulated eggs, and early embryos. Mol. Reprod. Dev. 81: 619–635, 2014. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Lene Kleppe
- Institute of Marine Research, Bergen, Norway
| | | | | | | | | |
Collapse
|
26
|
Wang S, Furmanek T, Kryvi H, Krossøy C, Totland GK, Grotmol S, Wargelius A. Transcriptome sequencing of Atlantic salmon (Salmo salar L.) notochord prior to development of the vertebrae provides clues to regulation of positional fate, chordoblast lineage and mineralisation. BMC Genomics 2014; 15:141. [PMID: 24548379 PMCID: PMC3943441 DOI: 10.1186/1471-2164-15-141] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Accepted: 02/13/2014] [Indexed: 11/26/2022] Open
Abstract
Background In teleosts such as Atlantic salmon (Salmo salar L.), segmentation and subsequent mineralisation of the notochord during embryonic stages are essential for normal vertebrae formation. However, the molecular mechanisms leading to segmentation and mineralisation of the notochord are poorly understood. The aim of this study was to identify genes/pathways acting in gradients over time and along the anterior-posterior axis during notochord segmentation and immediately prior to mineralisation of the vertebral bodies in Atlantic salmon. Results Notochord samples were collected from unsegmented, pre-segmented and segmented developmental stages. In each stage, the cellular core of the notochord was cut into three pieces along the longitudinal axis (anterior, mid, posterior). RNA was sequenced (22 million pair-end 100 bp/ library) and mapped to the salmon genome. 66569 transcripts were predicted and 55775 were annotated. In order to identify possible gradients leading to segmentation of the notochord, all 71 notochord-expressed hox genes were investigated, most of them displaying a typical anterior-posterior expression pattern along the notochord axis. The clustering of hox genes revealed a pattern that could be related to notochord segmentation. We further investigated how mineralisation is initiated in the notochord, and several factors related to chondrogenic lineage were identified (sox9, sox5, sox6, tgfb3, ihhb and col2a1), suggesting a cartilage-like character of the notochord. KEGG analysis of differentially expressed genes between stages revealed down-regulation of pathways associated with ECM, cell division, metabolism and development at onset of notochord segmentation. This implies that inhibitory signals produce segmentation of the notochord. One such potential inhibitory signal was identified, col11a2, which was detected in segments of non-mineralising notochord. Conclusions An incomplete salmon genome was successfully used to analyse RNA-seq data from the cellular core of the Atlantic salmon notochord. In transcriptome we found; hox gene patterns possibly linked to segmentation; down-regulation of pathways in the notochord at onset of segmentation; segmented expression of col11a2 in non-mineralised segments of the notochord; and a chondroblast-like footprint in the notochord.
Collapse
|
27
|
Kleppe L, Karlsen O, Edvardsen RB, Norberg B, Andersson E, Taranger GL, Wargelius A. Cortisol treatment of prespawning female cod affects cytogenesis related factors in eggs and embryos. Gen Comp Endocrinol 2013; 189:84-95. [PMID: 23660444 DOI: 10.1016/j.ygcen.2013.04.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 04/20/2013] [Accepted: 04/22/2013] [Indexed: 10/26/2022]
Abstract
A stable supply of viable eggs and embryos is crucial for successful farming of Atlantic cod. Stress during broodstock rearing can have negative effects on offspring, but little is known about the molecular mechanisms that cause abnormal development. Maternally transferred mRNAs have been shown to be essential for normal development, and stress may therefore influence their expression and the subsequent embryonic development. We investigated if mimicked stress in cod females affects mRNA concentrations in eggs/embryos, and if this can be linked to viability of embryos. Three weeks before peak spawning, 20 fish were intraperitoneally implanted with either cortisol-containing or cortisol-free (sham) osmotic pumps. At peak spawning all individuals were stripped and eggs were fertilized and incubated until hatching. Samples were collected from unfertilized eggs and embryos for analysis of gene expression (microarray), viability, steroids and vitellogenin. Plasma concentration of cortisol (ng/ml) in treated females was significantly higher at spawning (127.1±20.9) than that of sham control (11.3±6.7). This difference was also reflected in eggs and embryos. Percent fertilization, asymmetric cell division and hatching were not affected. However, numerous genes were differentially expressed in eggs and embryos in response to elevated cortisol, especially in maternal (oocyte and blastula) stages. Among these differentially expressed genes, some were found to be linked to cytogenesis (stxbp6, fbxw2, capn12, thbs4, sytl2, coro1c, sel1l3), induction of mesodermal fate (fgfrl1) and import of the glucocorticoid receptor to the cell nucleus (ipo7). Gene ontology overrepresentation analysis on the whole set of differentially expressed genes at maternal stages (539 genes) revealed enriched activity in membrane associated regions, which largely corresponds to cytogenesis related processes. These results suggest that despite no visible phenotypic effects in early embryos, broodstock stress affects the egg/embryonic transcriptome, especially in relation to cytogenesis. Furthermore, effects related to egg/embryo phenotypes are difficult to measure at early stages of development, and instead might become apparent at later life stages.
Collapse
Affiliation(s)
- Lene Kleppe
- Institute of Marine Research, P. O. Box 1870, 5817 Bergen, Norway.
| | | | | | | | | | | | | |
Collapse
|
28
|
Wang S, Kryvi H, Grotmol S, Wargelius A, Krossøy C, Epple M, Neues F, Furmanek T, Totland GK. Mineralization of the vertebral bodies in Atlantic salmon (Salmo salar L.) is initiated segmentally in the form of hydroxyapatite crystal accretions in the notochord sheath. J Anat 2013; 223:159-70. [PMID: 23711083 DOI: 10.1111/joa.12067] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2013] [Indexed: 12/14/2022] Open
Abstract
We performed a sequential morphological and molecular biological study of the development of the vertebral bodies in Atlantic salmon (Salmo salar L.). Mineralization starts in separate bony elements which fuse to form complete segmental rings within the notochord sheath. The nucleation and growth of hydroxyapatite crystals in both the lamellar type II collagen matrix of the notochord sheath and the lamellar type I collagen matrix derived from the sclerotome, were highly similar. In both matrices the hydroxyapatite crystals nucleate and accrete on the surface of the collagen fibrils rather than inside the fibrils, a process that may be controlled by a template imposed by the collagen fibrils. Apatite crystal growth starts with the formation of small plate-like structures, about 5 nm thick, that gradually grow and aggregate to form extensive multi-branched crystal arborizations, resembling dendritic growth. The hydroxyapatite crystals are always oriented parallel to the long axis of the collagen fibrils, and the lamellar collagen matrices provide oriented support for crystal growth. We demonstrate here for the first time by means of synchroton radiation based on X-ray diffraction that the chordacentra contain hydroxyapatite. We employed quantitative real-time PCR to study the expression of key signalling molecule transcripts expressed in the cellular core of the notochord. The results indicate that the notochord not only produces and maintains the notochord sheath but also expresses factors known to regulate skeletogenesis: sonic hedgehog (shh), indian hedgehog homolog b (ihhb), parathyroid hormone 1 receptor (pth1r) and transforming growth factor beta 1 (tgfb1). In conclusion, our study provides evidence for the process of vertebral body development in teleost fishes, which is initially orchestrated by the notochord.
Collapse
Affiliation(s)
- Shou Wang
- Department of Biology, University of Bergen, Bergen, Norway.
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Kleppe L, Edvardsen RB, Kuhl H, Malde K, Furmanek T, Drivenes Ø, Reinhardt R, Taranger GL, Wargelius A. Maternal 3'UTRs: from egg to onset of zygotic transcription in Atlantic cod. BMC Genomics 2012; 13:443. [PMID: 22937762 PMCID: PMC3462720 DOI: 10.1186/1471-2164-13-443] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/29/2012] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Zygotic transcription in fish embryos initiates around the time of gastrulation, and all prior development is initiated and controlled by maternally derived messenger RNAs. Atlantic cod egg and embryo viability is variable, and it is hypothesized that the early development depends upon the feature of these maternal RNAs. Both the length and the presence of specific motifs in the 3'UTR of maternal RNAs are believed to regulate expression and stability of the maternal transcripts. Therefore, the aim of this study was to characterize the overall composition and 3'UTR structure of the most common maternal RNAs found in cod eggs and pre-zygotic embryos. RESULTS 22229 Sanger-sequences were obtained from 3'-end sequenced cDNA libraries prepared from oocyte, 1-2 cell, blastula and gastrula stages. Quantitative PCR revealed that EST copy number below 9 did not reflect the gene expression profile. Consequently genes represented by less than 9 ESTs were excluded from downstream analyses, in addition to sequences with low-quality gene hits. This provided 12764 EST sequences, encoding 257 unique genes, for further analysis. Mitochondrial transcripts accounted for 45.9-50.6% of the transcripts isolated from the maternal stages, but only 12.2% of those present at the onset of zygotic transcription. 3'UTR length was predicted in nuclear sequences with poly-A tail, which identified 191 3'UTRs. Their characteristics indicated a more complex regulation of transcripts that are abundant prior to the onset of zygotic transcription. Maternal and stable transcripts had longer 3'UTR (mean 187.1 and 208.8 bp) and more 3'UTR isoforms (45.7 and 34.6%) compared to zygotic transcripts, where 15.4% had 3'UTR isoforms and the mean 3'UTR length was 76 bp. Also, diversity and the amount of putative polyadenylation motifs were higher in both maternal and stable transcripts. CONCLUSIONS We report on the most pronounced processes in the maternally transferred cod transcriptome. Maternal stages are characterized by a rich abundance of mitochondrial transcripts. Maternal and stable transcripts display longer 3'UTRs with more variation of both polyadenylation motifs and 3'UTR isoforms. These data suggest that cod eggs possess a complex array of maternal RNAs which likely act to tightly regulate early developmental processes in the newly fertilized egg.
Collapse
Affiliation(s)
- Lene Kleppe
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| | - Rolf B Edvardsen
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| | - Heiner Kuhl
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, D-14195, Berlin-Dahlem, Germany
| | - Ketil Malde
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| | - Tomasz Furmanek
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| | - Øyvind Drivenes
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| | - Richard Reinhardt
- Max-Planck Genome centre, MPI fuer Pflanzenzüchtungsforschung, Carl-von-Linné-Weg 10, D-80829, Koeln, Germany
| | - Geir L Taranger
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| | - Anna Wargelius
- Institute of Marine Research, P. O. Box 1870, Nordnesgaten 50, 5817, Bergen, Norway
| |
Collapse
|
30
|
Olsen RE, Svardal A, Eide T, Wargelius A. Stress and expression of cyclooxygenases (cox1, cox2a, cox2b) and intestinal eicosanoids, in Atlantic salmon, Salmo salar L. Fish Physiol Biochem 2012; 38:951-962. [PMID: 22131071 DOI: 10.1007/s10695-011-9581-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 11/22/2011] [Indexed: 05/31/2023]
Abstract
Prostaglandin H synthetases (cyclooxygenases) catalyze the initial reactions leading to prostanoids in animals. They form interesting links between diet and fish physiology as the type and nature of eicosanoids are affected by dietary lipid sources. Their expression is likely to be affected by tissues and environmental conditions leading to altered amount and ratio of eicosanoids. These mechanisms are, however, poorly understood in fish. In the present study, Atlantic salmon Salmo salar L. (1,000 g, 10°C, seawater) were subjected to acute chasing stress. Liver, kidney, spleen, gill, muscle, midgut and hindgut were extracted before and 1 h post-stress and analyzed for mRNA expression of cox1, cox2a and cox2b. Intestinal samples were further sampled over 24 h for both cox expression and analysis of 15 eicosanoids and isoprostanes of the n-3 and n-6 series. Results show a highly variable but consecutively expression of cox1, cox2a and cox2b in most of the tissues analyzed. Low levels were only found for cox2a in liver and cox2b in liver and kidney. The study reveals the general trend that cox1 is about 10 times the level of cox2b, which again is about 10 times the level of cox2a. Cox2b shows the highest level of expression in the gills indicating a possible higher requirement for this protein in gills. Imposing stress to the fish induces a temporal increase in the expression of cox2a in the midgut, while the gene expression of the other genes is not affected in any of the tissues analyzed. There is, however, a general tendency to increased expression of both cox2 genes that merits further studies. Stress had a profound effect on the intestinal eicosanoid content which showed a general decrease in midgut sections after stress that persisted for at least 24 h.
Collapse
Affiliation(s)
- R E Olsen
- Institute of Marine Research, Matre Research Station, 5984, Matredal, Norway.
| | - A Svardal
- Section for Pharmacology, Institute of Medicine, University of Bergen, 5021, Bergen, Norway
| | - T Eide
- Section for Pharmacology, Institute of Medicine, University of Bergen, 5021, Bergen, Norway
| | - A Wargelius
- Institute of Marine Research, PO Box 1870, Nordnes, 5817, Bergen, Norway
| |
Collapse
|
31
|
Sagstad A, Grotmol S, Kryvi H, Krossøy C, Totland GK, Malde K, Wang S, Hansen T, Wargelius A. Identification of vimentin- and elastin-like transcripts specifically expressed in developing notochord of Atlantic salmon (Salmo salar L.). Cell Tissue Res 2011; 346:191-202. [PMID: 22057848 DOI: 10.1007/s00441-011-1262-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 10/05/2011] [Indexed: 11/26/2022]
Abstract
The notochord functions as the midline structural element of all vertebrate embryos, and allows movement and growth at early developmental stages. Moreover, during embryonic development, notochord cells produce secreted factors that provide positional and fate information to a broad variety of cells within adjacent tissues, for instance those of the vertebrae, central nervous system and somites. Due to the large size of the embryo, the salmon notochord is useful to study as a model for exploring notochord development. To investigate factors that might be involved in notochord development, a normalized cDNA library was constructed from a mix of notochords from ∼500 to ∼800 day°. From the 1968 Sanger-sequenced transcripts, 22 genes were identified to be predominantly expressed in the notochord compared to other organs of salmon. Twelve of these genes were found to show expressional regulation around mineralization of the notochord sheath; 11 genes were up-regulated and one gene was down-regulated. Two genes were found to be specifically expressed in the notochord; these genes showed similarity to vimentin (acc. no GT297094) and elastin (acc. no GT297478). In-situ results showed that the vimentin- like transcript was expressed in both chordocytes and chordoblasts, whereas the elastin- like transcript was uniquely expressed in the chordoblasts lining the notochordal sheath. In salmon aquaculture, vertebral deformities are a common problem, and some malformations have been linked to the notochord. The expression of identified transcripts provides further insight into processes taking place in the developing notochord, prior to and during the early mineralization period.
Collapse
Affiliation(s)
- Anita Sagstad
- Department of Biology, University of Bergen, P.O. Box 7800, NO-5020 Bergen, Norway.
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Grini A, Hansen T, Berg A, Wargelius A, Fjelldal PG. The effect of water temperature on vertebral deformities and vaccine-induced abdominal lesions in Atlantic salmon, Salmo salar L. J Fish Dis 2011; 34:531-546. [PMID: 21623836 DOI: 10.1111/j.1365-2761.2011.01265.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study investigates the effects of water temperature (T) on vaccine-induced abdominal lesions (i.p. injection with oil-adjuvant vaccine) and vertebral deformities in Atlantic salmon. Quadruple groups of vaccinated (V) or unvaccinated (U) underyearling smolts were reared in tanks under four different temperature regimes for 6 weeks in fresh water (FW) followed by 6 weeks in sea water (SW). The four different T regimes were 10 °C FW-10 °C SW (10-10), 10 °C FW-16 °C SW (10-16), 16 °C FW-10 °C SW (16-10) and 16 °C FW-16 °C SW (16-16). After the temperature regimes were finished, the fish were group-tagged and transferred to a common sea cage for on-growth until harvest size. At termination, weight was significantly affected by both T and V, while lesion score and deformities were affected by T only. The weight difference between the largest and smallest U group was 20.3% (16-10 U: 2.4 kg, 10-16 U: 1.89 kg), while the largest difference between U and V fish within a T regime was 28.7% (16-16 U: 2.1 kg, 16-16 V: 1.5 kg). Fish from the 16-16, 16-10 and 10-16 regimes had a significant higher lesion score than those from the 10-10 regime. Fish from the 10-16 and 16-16 regimes displayed a significantly higher prevalence of vertebral deformities (palpation : 13-27%, radiology: 88-94%) than fish from the 10-10 and 16-10 regimes (palpation: 2-3%, radiology: 27-65%). Vertebra number 26 (located beneath the dorsal fin) was the most frequently affected vertebra in smolts, while vertebra number 43 (located above the anal fin) was most frequently affected in adults.
Collapse
Affiliation(s)
- A Grini
- Institute of Marine Research (IMR), Matre Research Station, Norway
| | | | | | | | | |
Collapse
|
33
|
Totland GK, Fjelldal PG, Kryvi H, Løkka G, Wargelius A, Sagstad A, Hansen T, Grotmol S. Sustained swimming increases the mineral content and osteocyte density of salmon vertebral bone. J Anat 2011; 219:490-501. [PMID: 21615400 DOI: 10.1111/j.1469-7580.2011.01399.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This study addresses the effects of increased mechanical load on the vertebral bone of post-smolt Atlantic salmon by forcing them to swim at controlled speeds. The fish swam continuously in four circular tanks for 9 weeks, two groups at 0.47 body lengths (bl) × s(-1) (non-exercised group) and two groups at 2 bl × s(-1) (exercised group), which is just below the limit for maximum sustained swimming speed in this species. Qualitative data concerning the vertebral structure were obtained from histology and electron microscopy, and quantitative data were based on histomorphometry, high-resolution X-ray micro-computed tomography images and analysis of bone mineral content, while the mechanical properties were tested by compression. Our key findings are that the bone matrix secreted during sustained swimming had significantly higher mineral content and mechanical strength, while no effect was detected on bone in vivo architecture. mRNA levels for two mineralization-related genes bgp and alp were significantly upregulated in the exercised fish, indicating promotion of mineralization. The osteocyte density of the lamellar bone of the amphicoel was also significantly higher in the exercised than non-exercised fish, while the osteocyte density in the cancellous bone was similar in the two groups. The vertebral osteocytes did not form a functional syncytium, which shows that salmon vertebral bone responds to mechanical loading in the absence of an extensive connecting syncytial network of osteocytic cell processes as found in mammals, indicating the existence of a different mechanosensing mechanism. The adaptive response to increased load is thus probably mediated by osteoblasts or bone lining cells, a system in which signal detection and response may be co-located. This study offers new insight into the teleost bone biology, and may have implications for maintaining acceptable welfare for farmed salmon.
Collapse
|
34
|
Gil Martens L, Lock EJ, Fjelldal PG, Wargelius A, Araujo P, Torstensen BE, Witten PE, Hansen T, Waagbø R, Ørnsrud R. Dietary fatty acids and inflammation in the vertebral column of Atlantic salmon, Salmo salar L., smolts: a possible link to spinal deformities. J Fish Dis 2010; 33:957-972. [PMID: 21091723 DOI: 10.1111/j.1365-2761.2010.01201.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Vegetable oils (Vo) are an alternative to fish oil (Fo) in aquaculture feeds. This study aimed to evaluate the effect of dietary soybean oil (Vo diet), rich in linoleic acid, and of dietary fish oil (Fo diet) on the development of spinal deformities under bacterial lipopolysaccharide (LPS)-induced chronic inflammation conditions in Atlantic salmon, Salmo salar L. Fish [25 g body weight (BW)] were fed the experimental diets for 99 days. On day 47 of feeding (40 g BW), fish were subjected to four experimental regimes: (i) intramuscular injections with LPS, (ii) sham-injected phosphate-buffered saline (PBS), (iii) intraperitoneally injected commercial oil adjuvant vaccine, or (iv) no treatment. The fish continued under a common feeding regime in sea water for 165 more days. Body weight was temporarily higher in the Vo group than in the Fo group prior to immunization and was also affected by the type of immunization. At the end of the trial, no differences were seen between the dietary groups. The overall prevalence of spinal deformities was approximately 14% at the end of the experiment. The Vo diet affected vertebral shape but did not induce spinal deformities. In groups injected with LPS and PBS, spinal deformities ranged between 21% and 38%, diet independent. Deformed vertebrae were located at or in proximity to the injection point. Assessment of inflammatory markers revealed high levels of plasma prostaglandin E₂ (PGE₂) in the Vo-fed and LPS-injected groups, suggesting an inflammatory response to LPS. Cyclooxigenase 2 (COX-2) mRNA expression in bone was higher in fish fed Fo compared to Vo-fed fish. Gene expression of immunoglobulin M (IgM) was up-regulated in bone of all LPS-injected groups irrespective of dietary oil. In conclusion, the study suggests that Vo is not a risk factor for the development of inflammation-related spinal deformities. At the same time, we found evidence that localized injection-related processes could trigger the development of vertebral body malformations.
Collapse
Affiliation(s)
- L Gil Martens
- NIFES, National Institute of Nutrition and Seafood Research, Bergen, Norway.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Wargelius A, Fjelldal PG, Nordgarden U, Grini A, Krossøy C, Grotmol S, Totland GK, Hansen T. Collagen type XI alpha1 may be involved in the structural plasticity of the vertebral column in Atlantic salmon (Salmo salar L.). ACTA ACUST UNITED AC 2010; 213:1207-16. [PMID: 20228357 DOI: 10.1242/jeb.040022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Atlantic salmon (Salmo salar L.) vertebral bone displays plasticity in structure, osteoid secretion and mineralization in response to photoperiod. Other properties of the vertebral bone, such as mineral content and mechanical strength, are also associated with common malformations in farmed Atlantic salmon. The biological mechanisms that underlie these changes in bone physiology are unknown, and in order to elucidate which factors might be involved in this process, microarray assays were performed on vertebral bone of Atlantic salmon reared under natural or continuous light. Eight genes were upregulated in response to continuous light treatment, whereas only one of them was upregulated in a duplicate experiment. The transcriptionally regulated gene was predicted to code for collagen type XI alpha1, a protein known to be involved in controlling the diameter of fibrillar collagens in mammals. Furthermore, the gene was highly expressed in the vertebrae, where spatial expression was found in trabecular and compact bone osteoblasts and in the chordoblasts of the notochordal sheath. When we measured the expression level of the gene in the tissue compartments of the vertebrae, the collagen turned out to be 150 and 25 times more highly expressed in the notochord and compact bone respectively, relative to the expression in the trabecular bone. Gene expression was induced in response to continuous light, and reduced in compressed vertebrae. The downregulation in compressed vertebrae was due to reduced expression in the compact bone, while expression in the trabecular bone and the notochord was unaffected. These data support the hypothesis that this gene codes for a presumptive collagen type XI alpha1, which may be involved in the regulatory pathway leading to structural adaptation of the vertebral architecture.
Collapse
Affiliation(s)
- A Wargelius
- Institute of Marine Research, PO Box 1870 Nordnes, Bergen, NO-5817, Norway.
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Krossøy C, Ørnsrud R, Wargelius A. Differential gene expression of bgp and mgp in trabecular and compact bone of Atlantic salmon (Salmo salar L.) vertebrae. J Anat 2009; 215:663-72. [PMID: 19811564 PMCID: PMC2796789 DOI: 10.1111/j.1469-7580.2009.01153.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2009] [Indexed: 11/28/2022] Open
Abstract
The tissue-specific gene expression of the vitamin K-dependent proteins bone gamma-carboxyglutamate-protein (BGP) and matrix gamma-carboxyglutamate-protein (MGP) in Atlantic salmon (Salmo salar L.) was investigated. In previous studies, BGP, the most abundant non-collagenous protein of bone, was almost exclusively associated with bone, whereas the non-structural protein MGP has a more widespread tissue distribution. In-situ hybridization of juvenile Atlantic salmon ( approximately 40 g, fresh water) vertebrae demonstrated expression of bgp and mgp mRNA in osteoblasts lining the trabecular bone, whereas no staining was observed in the compact bone. By separating the trabecular and compact bone of both juvenile ( approximately 40 g, fresh water) and adult ( approximately 1000 g, sea water) Atlantic salmon, we observed that the two vertebral bone compartments displayed different levels of bgp, whereas no such differences were seen for mgp. Measurements of the mineral content and Ca/P molar ratio in adult salmon revealed no significant differences between trabecular and compact bone. In conclusion, the osteoblasts covering the salmon vertebrae have unique gene expression patterns and levels of bgp and mgp. Further, the study confirms the presence of mRNA from the vitamin K-dependent proteins BGP and MGP in the vertebrae, fin and gills of Atlantic salmon.
Collapse
Affiliation(s)
- Christel Krossøy
- National Institute of Nutrition and Seafood ResearchBergen, Norway
- Department of Biology, University of BergenBergen, Norway
| | - Robin Ørnsrud
- National Institute of Nutrition and Seafood ResearchBergen, Norway
| | | |
Collapse
|
37
|
Wargelius A, Fjelldal PG, Nordgarden U, Hansen T. Continuous light affects mineralization and delays osteoid incorporation in vertebral bone of Atlantic salmon (Salmo salar L.). J Exp Biol 2009; 212:656-61. [PMID: 19218516 DOI: 10.1242/jeb.024000] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
In order to study the effects of photoperiod on fish bone, Atlantic salmon (Salmo salar L.) were exposed to two light regimes (natural and continuous light) from January until June. During the experimental period, several parameters related to the inorganic (minerals) and organic (osteoid) phases were measured. Changes in the organic phase were related to mechanical strength (yield-load) and the expression of the genes sonic hedgehog (shh) and collagen type I alpha 2 (col I). Co-variation between yield-load and the expression of both shh and col I were detected in both groups. It was also shown that fish on the continuous light regime had delayed activation of osteoid incorporation. Mineralization properties were measured with stiffness, mineral incorporation per day and expression of alkaline phosphatase (alp) and matrix Gla protein (mgp). Stiffness, mineral incorporation and gene expression followed the same trend in both light groups in late spring, whereas an increase in the expression of mgp and alp was detected in April, followed by significantly higher stiffness at last sampling in both light groups. These results indicate that constant light affects mineralization and delays osteoid incorporation in Atlantic salmon during the spring. However, in this experiment light treatment did not promote the development of vertebral deformities. Our results also suggest that shh can be used as a marker of osteoblast proliferation and col I a marker of osteoid incorporation, and that both alp and mgp expression could be associated with a rapid increase in mineralization in Atlantic salmon vertebrae.
Collapse
|
38
|
Gotensparre SM, Andersson E, Wargelius A, Hansen T, Johnston IA. Insight into the complex genetic network of tetraploid Atlantic salmon (Salmo salar L.): description of multiple novel Pax-7 splice variants. Gene 2006; 373:8-15. [PMID: 16567062 DOI: 10.1016/j.gene.2005.12.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 12/04/2005] [Accepted: 12/05/2005] [Indexed: 10/24/2022]
Abstract
Paired box transcription factor 7 (Pax-7) cDNA was isolated from the skeletal muscle and brain of alevin and adult stages of Atlantic salmon, identifying 10 variants categorised as novel or established insertions (ins) or deletions (del). Two putative Pax-7 paralogs were identified (denoted Pax-7alpha and Pax-7beta) on the basis of the length and sequences of intron 3 (218 and 248 bp) and versions of ins1 and ins2. Pax-7beta contained a threonine variant of ins1 (GQY[T]GPEYVYCGT), and a shortened variant of ins2 (GEAS). Pattern identification revealed the threonine variant of ins1 includes a potential phosphorylation site (casein kinase II). Thus, the tetraploid Atlantic salmon genome appears to contain at least two putative copies and multiple splice variants of Pax-7. In situ hybridisation localised Pax-7 to mononuclear cells in the fast muscle of adult Atlantic salmon, while quantitative real-time PCR showed Pax-7alpha to be more highly expressed in brain than in skeletal muscle.
Collapse
Affiliation(s)
- Susan M Gotensparre
- Gatty Marine Laboratory, School of Biology, University of St Andrews, St Andrews, Fife KY16 8LB, UK
| | | | | | | | | |
Collapse
|
39
|
Wargelius A, Fjelldal PG, Benedet S, Hansen T, Björnsson BT, Nordgarden U. A peak in gh-receptor expression is associated with growth activation in Atlantic salmon vertebrae, while upregulation of igf-I receptor expression is related to increased bone density. Gen Comp Endocrinol 2005; 142:163-8. [PMID: 15862560 DOI: 10.1016/j.ygcen.2004.12.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2004] [Accepted: 12/14/2004] [Indexed: 11/26/2022]
Abstract
Growth hormone (GH) and insulin-like growth factor-I (IGF-I) play major roles in the endocrine regulation of fish growth, but their interdependency and mode of action has not been well elucidated. The GH-IGF-I system is essential for normal vertebral growth in mouse, but this has not been studied in fish. To study the interplay between GH, IGF-I, and their receptors, postsmolt Atlantic salmon were studied during spring growth (January-June 2003). From January to June, fish were sampled regularly for plasma and vertebral bone. The vertebra was collected from the same anterior-posterior position. The growth hormone receptor (ghr) (There is no determined nomenclature of salmon genes but we stick to the nomenclature which is consequent for zebrafish, where all gene names are named with small letters and in italic.) expression in the vertebrae peaked in the end of February coinciding with high levels of plasma GH and IGF-I, and an increase of vertebral growth rate. From April to June, plasma IGF-I levels decreased together with ghr expression in the vertebrae, while plasma GH did not decrease. In May and June, expression of the igf-I receptor (igf-Ir) increased 4- to 5-fold, which coincided with an increase in bone density. The changes seen in gene expression of the IGF-I and GH receptors suggest that these hormones are involved in vertebral growth and bone density.
Collapse
Affiliation(s)
- Anna Wargelius
- Institute of Marine Research, Matre, N-5984 Matredal, Norway.
| | | | | | | | | | | |
Collapse
|
40
|
Wargelius A, Fjelldal PG, Hansen T. Heat shock during early somitogenesis induces caudal vertebral column defects in Atlantic salmon (Salmo salar). Dev Genes Evol 2005; 215:350-7. [PMID: 15798920 DOI: 10.1007/s00427-005-0482-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2004] [Accepted: 03/07/2005] [Indexed: 11/28/2022]
Abstract
In several terrestrial vertebrates, heat shock (HS) during somitogenesis causes vertebral deformities. To determine if vertebral deformities can occur due to sudden temperature changes during early development in fish, Atlantic salmon embryos were HS treated during somitogenesis. Ten months later these individuals displayed a high prevalence of caudal vertebral column condensations (27-34%). The defects were located caudally of the abdominal cavity, displaying an even distribution in this region independent of time of HS. To determine if HS disturbed vertebral development during somitogenesis, two genes coding for markers of skeletal development were identified, namely, the secreted protein Shh (Sashh) and the transcription factor Twist (Satwist). These proteins are involved in the proliferation and specification of presumptive skeletal cells (sclerotome) in vertebrates. The spatial expression pattern of sashh and satwist in salmon indicated a functional conservation of these proteins. Furthermore, HS embryos displayed expressional disturbance in both sashh and satwist, indicating an effect of HS on sclerotomal cell patterning. However, the HS-protecting ability in embryos seems to be individually regulated because reduction in gene expression was not detected at all stages; in addition, HS did not induce somitic disturbance and vertebral deformity in all embryos.
Collapse
Affiliation(s)
- Anna Wargelius
- Institute of Marine Research, P.O. Box 1870, Nordnes, 5817 Bergen, Norway.
| | | | | |
Collapse
|
41
|
Abstract
Homologues of the homeobox genes sine oculis (so) and eyeless (ey) are important regulators of eye development in both vertebrates and invertebrates. A Drosophila paralogue of so, optix, is an orthologue of the vertebrate Six3 gene family. Our analysis of zebrafish six3.1 demonstrated retinal expression in two separate cell layers and the ciliary marginal zone. This pattern is consistent with the observations of Six3 in other vertebrates and indicates functional conservation. We studied the 5(') flanking region of six3.1 and showed that separate enhancing elements are required for expression at different stages of eye development. This analysis also revealed specific binding of zebrafish Pax6.1 protein to an element required for six3.1 expression in ganglion cells. Furthermore, an enhancement of six3.1 transcription by Pax6.1 was observed by co-injection experiments. These results provide evidence for a direct regulatory interaction between vertebrate Pax6 and Six3 genes in eye development.
Collapse
Affiliation(s)
- Anna Wargelius
- Department of Molecular Biology, University of Bergen, P.O. Box 7800, N-5020 Bergen, Norway
| | | | | | | |
Collapse
|
42
|
Abstract
RNA interference (RNAi) is a phenomenon induced by double-stranded RNA (dsRNA) in which gene expression is inhibited through specific degradation of mRNA. The mechanism involves conversion of dsRNA into short RNAs that direct ribonucleases to homologous mRNA targets. This process is related to normal defence against viruses and mobilisation of transposons. Treatment with dsRNA has become an important method for analysing gene functions in invertebrate organisms. RNAi has also been demonstrated in several vertebrate species but with lower efficiency. Development of procedures for in vivo production of dsRNA may provide efficient tools for tissue- and stage-specific gene targeting.
Collapse
Affiliation(s)
- A Fjose
- Department of Molecular Biology, University of Bergen, HIB, PO Box 7800, N-5020 Bergen, Norway.
| | | | | | | |
Collapse
|
43
|
Bolstad AI, Wargelius A, Nakken B, Haga HJ, Jonsson R. Fas and Fas ligand gene polymorphisms in primary Sjögren's syndrome. J Rheumatol 2000; 27:2397-405. [PMID: 11036836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVE To screen for polymorphisms in the apoptosis regulating Fas and Fas ligand (FasL) genes in patients with primary Sjögren's syndrome (SS), and to explore associations with susceptibility to the disease. METHODS Polymorphisms in Fas and FasL of 70 patients with primary SS and 72 controls were determined by polymerase chain reaction combined with the restriction enzyme fingerprinting single strand conformation polymorphism technique, verified by automatic sequencing and natural or amplification created restriction site tests. RESULTS Polymorphisms were found in both Fas and FasL, but only some of the Fas polymorphisms were found in statistically significant differences between patients and controls. Patients displayed a higher frequency of the G/G genotype at position -671 than the controls, and the -671 G allele frequency for primary SS was increased compared to controls. A higher frequency of the C allele at position IVS2nt176 and IVS5nt82 was also found. Of note, the nucleotide variants in intron 2 and intron 5 were associated. CONCLUSION We describe the positions and frequencies of several polymorphisms in the genes encoding Fas and FasL in patients with primary SS. None caused any amino acid change. Three Fas alleles, of which one is located in the promoter area, showed significant although modest differences between patients and controls.
Collapse
Affiliation(s)
- A I Bolstad
- Broegelmann Research Laboratory, Center for Medical Genetics and Molecular Medicine, Institute of Medicine, Haukeland University Hospital, Bergen, Norway.
| | | | | | | | | |
Collapse
|
44
|
Abstract
Treatment with double-stranded RNA (dsRNA) has been shown to interfere with the function of specific genes in various invertebrate species. However, it has not yet been reported that this technique can be applied to vertebrates as well. We have investigated whether dsRNA treatment will inhibit gene function in zebrafish embryos. By microinjecting dsRNA corresponding to three genetically characterised genes we produced embryonic defects that were similar to the known mutant phenotypes of these loci. The efficiency of inducing specific defects (20-30%) was about 10-fold higher than in experiments with antisense RNA. We also observed that the level of the endogenous mRNA in zebrafish embryos was substantially reduced throughout the embryo following dsRNA injection. However, the interference of gene function showed a strong dependence on the amount of dsRNA. These findings suggest that dsRNA-mediated interference will become an important tool for analysing the functional roles of genes in zebrafish and other vertebrates.
Collapse
Affiliation(s)
- A Wargelius
- Department of Molecular Biology, University of Bergen, HIB, Bergen, N-5020, Norway
| | | | | |
Collapse
|