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Kang JH, Schartl M, Walter RB, Meyer A. Comprehensive phylogenetic analysis of all species of swordtails and platies (Pisces: Genus Xiphophorus) uncovers a hybrid origin of a swordtail fish, Xiphophorus monticolus, and demonstrates that the sexually selected sword originated in the ancestral lineage of the genus, but was lost again secondarily. BMC Evol Biol 2013; 13:25. [PMID: 23360326 PMCID: PMC3585855 DOI: 10.1186/1471-2148-13-25] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 01/22/2013] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Males in some species of the genus Xiphophorus, small freshwater fishes from Meso-America, have an extended caudal fin, or sword - hence their common name "swordtails". Longer swords are preferred by females from both sworded and - surprisingly also, non-sworded (platyfish) species that belong to the same genus. Swordtails have been studied widely as models in research on sexual selection. Specifically, the pre-existing bias hypothesis was interpreted to best explain the observed bias of females in presumed ancestral lineages of swordless species that show a preference for assumed derived males with swords over their conspecific swordless males. However, many of the phylogenetic relationships within this genus still remained unresolved. Here we construct a comprehensive molecular phylogeny of all 26 known Xiphophorus species, including the four recently described species (X. kallmani, X. mayae, X. mixei and X. monticolus). We use two mitochondrial and six new nuclear markers in an effort to increase the understanding of the evolutionary relationships among the species in this genus. Based on the phylogeny, the evolutionary history and character state evolution of the sword was reconstructed and found to have originated in the common ancestral lineage of the genus Xiphophorus and that it was lost again secondarily. RESULTS We estimated the evolutionary relationships among all known species of the genus Xiphophorus based on the largest set of DNA markers so far. The phylogeny indicates that one of the newly described swordtail species, Xiphophorus monticolus, is likely to have arisen through hybridization since it is placed with the southern platyfish in the mitochondrial phylogeny, but with the southern swordtails in the nuclear phylogeny. Such discordance between these two types of markers is a strong indication for a hybrid origin. Additionally, by using a maximum likelihood approach the possession of the sexually selected sword trait is shown to be the most likely ancestral state for the genus Xiphophorus. Further, we provide a well supported estimation of the phylogenetic relationships between the previously unresolved northern swordtail groups. CONCLUSIONS This comprehensive molecular phylogeny of the entire genus Xiphophorus provides evidence that a second swordtail species, X. monticolus, arose through hybridization. Previously, we demonstrated that X. clemenciae, another southern swordtail species, arose via hybridization. These findings highlight the potential key role of hybridization in the evolution of this genus and suggest the need for further investigations into how hybridization contributes to speciation more generally.
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Affiliation(s)
- Ji Hyoun Kang
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz 78457, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
| | - Manfred Schartl
- Physiological Chemistry, Biozentrum, University of Würzburg, Am Hubland, Würzburg, 97074, Germany
| | - Ronald B Walter
- Department of Chemistry and Biochemistry, Texas State University-San Marcos, 601 University Dr, San Marcos, TX, 78666, USA
| | - Axel Meyer
- Lehrstuhl für Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz 78457, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
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102
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Ng'oma E, Valdesalici S, Reichwald K, Cellerino A. Genetic and morphological studies of Nothobranchius (Cyprinodontiformes) from Malawi with description of Nothobranchius wattersi sp. nov. J Fish Biol 2013; 82:165-188. [PMID: 23331144 DOI: 10.1111/jfb.12001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Molecular and morphological data were used to explore evolutionary differentiation among populations of Nothobranchius in the Lake Malawi-upper Shire River and the Lakes Chilwa-Chiuta drainage systems in Malawi. The aim of the study was to test the hypothesis that Nothobranchius of the Malawi-Shire system constitute a separate evolutionary group from Nothobranchius kirki. Mitochondrial and nuclear sequence data show a strongly supported phylogenetic split into two monophyletic groups separating the Lake Malawi basin fish from N. kirki. Unlike N. kirki, Lake Malawi-Shire fish do not deviate from neutrality and express an excess of rare haplotypes and mutations in terminal branches, characteristic of recently expanded populations. Further, the two groups significantly differ in morphology. Two body characters (dorsal-fin base length and pre-pelvic-pre-anal distance) are significantly different between the two species in both sexes. Several other characters are significantly different in either male or female comparisons with respect to both standard and head lengths, and robust morphological differentiation is detected by multivariate analysis. The two groups are readily distinguished on the basis of male colouration, especially in scale centres and the caudal fin. On the basis of this differentiation at the molecular and morphological levels, in addition to colouration, the Lake Malawi-Shire fish are hereby formally recognized as constituting a new species, Nothobranchius wattersi. This distinction is in agreement with the geomorphologic and recent climatic history in the region.
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Affiliation(s)
- E Ng'oma
- Leibniz Institute for Age Research-Fritz Lipmann Institute, Beutenbergstraße 11, D-07745 Jena, Germany
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103
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Liang X, Nie X, Ying G, An T, Li K. Assessment of toxic effects of triclosan on the swordtail fish (Xiphophorus helleri) by a multi-biomarker approach. Chemosphere 2013; 90:1281-1288. [PMID: 23098581 DOI: 10.1016/j.chemosphere.2012.09.087] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 09/24/2012] [Accepted: 09/25/2012] [Indexed: 06/01/2023]
Abstract
The toxic effects of triclosan (TCS) on the swordtail fish (Xiphophorus helleri) were assessed based on various biomarkers including enzymatic activities of ethoxyresorufin O-deethylase (EROD), erythromycin N-demethylase (ERND) and glutathione-s-transferase (GST) and mRNA expression levels of CYP1A, CYP3A, glutathione S-transferase (GST) and P-glycoprotein (P-gp). The acute toxicity test showed the LC(50) value of 1.47 mg L(-1) for TCS. The mRNA expressions of CYP1A, CYP3A, GST and P-gp showed dose-effect relationships in female swordtail fish when exposed to TCS, These mRNA expression levels were found more sensitive to TCS exposure than the enzymatic activities of EROD, ERND and GST do. In addition, the male fish displayed higher gene expression levels and more dramatic changes in enzyme activities than the females did. Our data further demonstrated that TCS was a typical inducer to Phase I and Phase II metabolism enzymes and genes, suggesting it is a potential ecotoxicological risk to aquatic ecosystems.
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Affiliation(s)
- Ximei Liang
- Department of Ecology, Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
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104
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Ellison A, Allainguillaume J, Girdwood S, Pachebat J, Peat KM, Wright P, Consuegra S. Maintaining functional major histocompatibility complex diversity under inbreeding: the case of a selfing vertebrate. Proc Biol Sci 2012; 279:5004-13. [PMID: 23075838 PMCID: PMC3497237 DOI: 10.1098/rspb.2012.1929] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [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] [Received: 08/17/2012] [Accepted: 09/24/2012] [Indexed: 01/17/2023] Open
Abstract
Major histocompatibility complex (MHC) genes encode proteins that present pathogen-derived antigens to T-cells, initiating the adaptive immune response in vertebrates. Although populations with low MHC diversity tend to be more susceptible to pathogens, some bottlenecked populations persist and even increase in numbers despite low MHC diversity. Thus, the relative importance of MHC diversity versus genome-wide variability for the long-term viability of populations after bottlenecks and/or under high inbreeding is controversial. We tested the hypothesis that genome-wide inbreeding (estimated using microsatellites) should be more critical than MHC diversity alone in determining pathogen resistance in the self-fertilizing fish Kryptolebias marmoratus by analysing MHC diversity and parasite loads in natural and laboratory populations with different degrees of inbreeding. Both MHC and neutral diversities were lost after several generations of selfing, but we also found evidence of parasite selection acting on MHC diversity and of non-random loss of alleles, suggesting a possible selective advantage of those individuals with functionally divergent MHC, in accordance with the hypothesis of divergent allele advantage. Moreover, we found that parasite loads were better explained by including MHC diversity in the model than by genome-wide (microsatellites) heterozygosity alone. Our results suggest that immune-related overdominance could be the key in maintaining variables rates of selfing and outcrossing in K. marmoratus and other mixed-mating species.
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Affiliation(s)
- A. Ellison
- IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK
| | - J. Allainguillaume
- Department of Applied Sciences, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK
| | - S. Girdwood
- IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK
| | - J. Pachebat
- IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK
| | - K. M. Peat
- IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK
| | - P. Wright
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, CanadaN1G 2W1
| | - S. Consuegra
- IBERS, Aberystwyth University, Penglais Campus, Aberystwyth SY23 3DA, UK
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105
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Kelley JL, Yee MC, Lee C, Levandowsky E, Shah M, Harkins T, Earley RL, Bustamante CD. The possibility of de novo assembly of the genome and population genomics of the mangrove rivulus, Kryptolebias marmoratus. Integr Comp Biol 2012; 52:737-42. [PMID: 22723055 PMCID: PMC3501098 DOI: 10.1093/icb/ics094] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
How organisms adapt to the range of environments they encounter is a fundamental question in biology. Elucidating the genetic basis of adaptation is a difficult task, especially when the targets of selection are not known. Emerging sequencing technologies and assembly algorithms facilitate the genomic dissection of adaptation and population differentiation in a vast array of organisms. Here we describe the attributes of Kryptolebias marmoratus, one of two known self-fertilizing hermaphroditic vertebrates that make this fish an attractive genetic system and a model for understanding the genomics of adaptation. Long periods of selfing have resulted in populations composed of many distinct naturally homozygous strains with a variety of identifiable, and apparently heritable, phenotypes. There also is strong population genetic structure across a diverse range of mangrove habitats, making this a tractable system in which to study differentiation both within and among populations. The ability to rear K. marmoratus in the laboratory contributes further to its value as a model for understanding the genetic drivers for adaptation. To date, microsatellite markers distinguish wild isogenic strains but the naturally high homozygosity improves the quality of de novo assembly of the genome and facilitates the identification of genetic variants associated with phenotypes. Gene annotation can be accomplished with RNA-sequencing data in combination with de novo genome assembly. By combining genomic information with extensive laboratory-based phenotyping, it becomes possible to map genetic variants underlying differences in behavioral, life-history, and other potentially adaptive traits. Emerging genomic technologies provide the required resources for establishing K. marmoratus as a new model organism for behavioral genetics and evolutionary genetics research.
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Affiliation(s)
- Joanna L Kelley
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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106
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Oufiero CE, Jugo K, Tran P, Garland T. As the Sword Grows: Individual Variation and Ontogenetic Effects of a Sexually Selected Trait on Locomotor Performance in Xiphophorus hellerii. Physiol Biochem Zool 2012; 85:684-93. [PMID: 23099465 DOI: 10.1086/666089] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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107
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Ornelas-García CP, Alda F, Díaz-Pardo E, Gutiérrez-Hernández A, Doadrio I. Genetic diversity shaped by historical and recent factors in the live-bearing twoline skiffia Neotoca bilineata. J Fish Biol 2012; 81:1963-1984. [PMID: 23130693 DOI: 10.1111/j.1095-8649.2012.03456.x] [Citation(s) in RCA: 9] [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] [Indexed: 06/01/2023]
Abstract
The endangered twoline skiffia Neotoca bilineata, a viviparous fish of the subfamily Goodeinae, endemic to central Mexico (inhabiting two basins, Cuitzeo and Lerma-Santiago) was evaluated using genetic and habitat information. The genetic variation of all remaining populations of the species was analysed using both mitochondrial and microsatellite markers and their habitat conditions were assessed using a water quality index (I(WQ)). An 80% local extinction was found across the distribution of N. bilineata. The species was found in three of the 16 historical localities plus one previously unreported site. Most areas inhabited by the remaining populations had I(WQ) scores unsuitable for the conservation of freshwater biodiversity. Populations showed low but significant genetic differentiation with both markers (mtDNA φ(ST) = 0.076, P < 0.001; microsatellite F(ST) = 0.314, P < 0.001). Borbollon, in the Cuitzeo Basin, showed the highest level of differentiation and was identified as a single genetic unit by Bayesian assignment methods. Rio Grande de Morelia and Salamanca populations showed the highest genetic diversity and also a high migration rate facilitated by an artificial channel that connected the two basins. Overall, high genetic diversity values were observed compared with other freshwater fishes (average N(a) = 16 alleles and loci and mean ±S.D. H(o) = 0.63 ± 0.10 and nucleotide diversity π = 0.006). This suggests that the observed genetic diversity has not diminished as rapidly as the species' habitat destruction. No evidence of correlation between habitat conditions and genetic diversity was found. The current pattern of genetic diversity may be the result of both historical factors and recent modifications of the hydrological system. The main threat to the species may be the rapid habitat deterioration and associated demographic stochasticity rather than genetic factors.
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Affiliation(s)
- C P Ornelas-García
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain.
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108
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Langerhans RB, Gifford ME, Domínguez-Domínguez O, García-Bedoya D, DeWitt TJ. Gambusia quadruncus (Cyprinodontiformes: Poeciliidae): a new species of mosquitofish from east-central México. J Fish Biol 2012; 81:1514-1539. [PMID: 23020559 DOI: 10.1111/j.1095-8649.2012.03397.x] [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] [Indexed: 05/28/2023]
Abstract
Gambusia quadruncus n. sp., the llanos mosquitofish, is described from east-central México. The region inhabited by the species represents a hotspot of diversity of Gambusia, and G. quadruncus sometimes coexists with at least three congeners. The species differs from its closest relative, Gambusia affinis, in several characteristics with plausible effects on reproductive isolation, e.g. body size, body and fin morphology, male genital morphology (distal tip of gonopodium) and female anal spot morphology (colouration near the urogenital sinus). Moreover, combined analysis of mitochondrial and nuclear gene sequence data (c. 2158 total base pairs) indicates reciprocal monophyly of G. quadruncus and its sister species G. affinis, with levels of genetic divergence suggesting the two species diverged from one another over a million years ago. The origin of G. quadruncus may reflect a vicariant event associated with Pliocene orogenesis in the Tamaulipas Arch and a frontal section of the Sierra Madre Oriental (Lleran Mesas). Gambusia quadruncus inhabits a variety of freshwater habitats across several river drainages, with its range spanning at least 350 km from north to south, covering over 25 000 km(2). A key to aid identification of the species is provided.
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Affiliation(s)
- R B Langerhans
- Department of Biology and WM Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC 27695-7617, USA.
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109
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Abstract
The increase in reports of novel diseases in a wide range of ecosystems, both terrestrial and marine, has been linked to many factors including exposure to novel pathogens and changes in the global climate. Prevalence of skin cancer in particular has been found to be increasing in humans, but has not been reported in wild fish before. Here we report extensive melanosis and melanoma (skin cancer) in wild populations of an iconic, commercially-important marine fish, the coral trout Plectropomus leopardus. The syndrome reported here has strong similarities to previous studies associated with UV induced melanomas in the well-established laboratory fish model Xiphophorus. Relatively high prevalence rates of this syndrome (15%) were recorded at two offshore sites in the Great Barrier Reef Marine Park (GBRMP). In the absence of microbial pathogens and given the strong similarities to the UV-induced melanomas, we conclude that the likely cause was environmental exposure to UV radiation. Further studies are needed to establish the large scale distribution of the syndrome and confirm that the lesions reported here are the same as the melanoma in Xiphophorus, by assessing mutation of the EGFR gene, Xmrk. Furthermore, research on the potential links of this syndrome to increases in UV radiation from stratospheric ozone depletion needs to be completed.
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Affiliation(s)
- Michael Sweet
- Coral Health and Disease Laboratory, School of Biology, Newcastle Institute for Research on Sustainability, Newcastle University, Newcastle upon Tyne, United Kingdom.
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110
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Larson AD, Scarborough PL, Sayre CL, Johnson JB. What can phylogeographic breaks in the livebearer Poeciliopsis turrubarensis tell about fish community boundaries in western Costa Rica? J Fish Biol 2012; 80:728-736. [PMID: 22380567 DOI: 10.1111/j.1095-8649.2011.03213.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study asks if the geographic boundary delineating two fish communities in western Costa Rica is congruent with a phylogeographic break in a single widespread fish species Poeciliopsis turrubarensis (Poeciliidae) that spans this area. Such congruence would suggest that a common historical event (e.g. geological or climatic) could be responsible for both patterns. It was found that there was a shared break across a region in central Costa Rica suggesting a common cause may be responsible for both the abrupt shift in fish community composition and the genetic break in P. turrubarensis.
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Affiliation(s)
- A D Larson
- Evolutionary Ecology Laboratories, Department of Biology, Brigham Young University, Provo, UT 84602, USA.
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111
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Shen Y, Catchen J, Garcia T, Amores A, Beldroth I, Wagner JR, Zhang Z, Postlethwait J, Warren W, Schartl M, Walter RB. Identification of transcriptome SNPs between Xiphophorus lines and species for assessing allele specific gene expression within F₁ interspecies hybrids. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:102-8. [PMID: 21466860 PMCID: PMC3178741 DOI: 10.1016/j.cbpc.2011.03.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [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: 02/09/2011] [Revised: 03/28/2011] [Accepted: 03/28/2011] [Indexed: 12/25/2022]
Abstract
Variations in gene expression are essential for the evolution of novel phenotypes and for speciation. Studying allelic specific gene expression (ASGE) within interspecies hybrids provides a unique opportunity to reveal underlying mechanisms of genetic variation. Using Xiphophorus interspecies hybrid fishes and high-throughput next generation sequencing technology, we were able to assess variations between two closely related vertebrate species, Xiphophorus maculatus and Xiphophorus couchianus, and their F(1) interspecies hybrids. We constructed transcriptome-wide SNP polymorphism sets between two highly inbred X. maculatus lines (JP 163 A and B), and between X. maculatus and a second species, X. couchianus. The X. maculatus JP 163 A and B parental lines have been separated in the laboratory for ≈70 years and we were able to identify SNPs at a resolution of 1 SNP per 49 kb of transcriptome. In contrast, SNP polymorphisms between X. couchianus and X. maculatus species, which diverged ≈5-10 million years ago, were identified about every 700 bp. Using 6524 transcripts with identified SNPs between the two parental species (X. maculatus and X. couchianus), we mapped RNA-seq reads to determine ASGE within F(1) interspecies hybrids. We developed an in silico X. couchianus transcriptome by replacing 90,788 SNP bases for X. maculatus transcriptome with the consensus X. couchianus SNP bases and provide evidence that this procedure overcomes read mapping biases. Employment of the in silico reference transcriptome and tolerating 5 mismatches during read mapping allow direct assessment of ASGE in the F(1) interspecies hybrids. Overall, these results show that Xiphophorus is a tractable vertebrate experimental model to investigate how genetic variations that occur during speciation may affect gene interactions and the regulation of gene expression.
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Affiliation(s)
- Yingjia Shen
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Julian Catchen
- Institute of Neuroscience, University of Oregon, 1425 E. 13th Avenue, Eugene, OR 97403 USA
| | - Tzintzuni Garcia
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Angel Amores
- Institute of Neuroscience, University of Oregon, 1425 E. 13th Avenue, Eugene, OR 97403 USA
| | - Ion Beldroth
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Jonathon R Wagner
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Ziping Zhang
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - John Postlethwait
- Institute of Neuroscience, University of Oregon, 1425 E. 13th Avenue, Eugene, OR 97403 USA
| | - Wes Warren
- Genome Sequencing Center, Washington University School of Medicine, 4444 Forest Park Blvd., St Louis, MO 63108, USA
| | - Manfred Schartl
- Physiological Chemistry I, University of Würzburg, Biozentrum, Am Hubland, 97074 Würzburg, Germany
| | - Ronald B. Walter
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
- Corresponding author. , PHONE: (512) 245-0357, FAX: (512) 245-2374, Address: Department of Chemistry & Biochemistry, 419 CEN, Texas State University, 601 University Drive, San Marcos, TX, 78666
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112
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Perez AN, Oehlers L, Heater SJ, Booth RE, Walter RB, David WM. Proteomic analyses of the Xiphophorus Gordon-Kosswig melanoma model. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:81-8. [PMID: 21672637 PMCID: PMC3223274 DOI: 10.1016/j.cbpc.2011.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [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: 02/03/2011] [Revised: 05/27/2011] [Accepted: 05/30/2011] [Indexed: 12/22/2022]
Abstract
Interspecies hybridization between the platyfish X. maculatus Jp 163 A, and the swordtail X. helleri (Sarabia), generates F(1) hybrids with pronounced melanin pigmentation. Backcrossing of F(1) hybrids with the X. helleri parent results in 25% of progeny that will spontaneously develop melanoma. We have applied proteomic methods to this Gordon-Kosswig (G-K) melanoma model to identify candidate proteins that exhibit modulated expression in fin tissue due to interspecies hybridization and progression of hybrid tissues to spontaneous melanoma. Difference Gel Electrophoresis (DIGE) was used to minimize the variability commonly observed in quantitative analyses of comparative protein samples. Following identification of up- or down-regulated protein expression by DIGE, candidate protein spots were identified by mass spectrometric sequencing. Several protein expression differences displayed in interspecies hybrids were identified and compared to distinct differences that occur upon backcrossing and progression to melanoma. These studies are important for the identification of distinct biochemical pathways involved in the variety of Xiphophorus interspecies hybrid tumor models.
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Affiliation(s)
| | | | | | | | | | - Wendi M. David
- Corresponding author. Texas State University-San Marcos, Department of Chemistry & Biochemistry, 419 CEN, 601 University Drive, San Marcos, TX, 78666, USA, , PHONE: (512) 245-4637; FAX: (512) 245-2374
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113
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Fernandez AA, Paniker L, Garcia R, Mitchell DL. Recent advances in sunlight-induced carcinogenesis using the Xiphophorus melanoma model. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:64-70. [PMID: 21457786 PMCID: PMC3164944 DOI: 10.1016/j.cbpc.2011.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [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: 02/08/2011] [Revised: 03/23/2011] [Accepted: 03/23/2011] [Indexed: 01/25/2023]
Abstract
Unlike breast and prostate cancers, the nature and sequence of critical genetic and epigenetic events involved in the initiation and progression of melanoma are not well understood. A contributing factor to this dilemma, especially given our current understanding of the importance of UV light in melanoma etiology, is the lack of quality UV-inducible melanoma animal models. In this study we elaborate on the capability of UV light to induce cutaneous malignant melanomas (CMM) in Xiphophorus fishes, which were previously found to develop melanomas after acute neonatal UVB irradiation. In two separate tumorigenesis experiments, we exposed adult Xiphophorus hybrids to either acute UVB irradiations (5 consecutive daily treatments) or chronic solar irradiations (continuous UVA/UVB treatment for 9 months). Acute adult UVB irradiation resulted in the significant induction of melanomas, and moreover, this induction rate is equivalent to that of animals exposed to acute neonatal UVB irradiation. This study represents the first evidence that acute adult UVB irradiation, in the absence of any early life exposures, induces CMM. Similar to the findings conducted on other divergent melanoma models, including HGF/SF transgenic mice and Monodelphis domestica, prolonged chronic solar UV was not a factor in melanomagenesis.
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Affiliation(s)
- André A Fernandez
- The University of Texas MD Anderson Cancer Center, Department of Carcinogenesis, 1808 Park Road 1C, Smithville, TX 78957, USA.
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114
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Garcia T, Shen Y, Catchen J, Amores A, Schartl M, Postlethwait J, Walter RB. Effects of short read quality and quantity on a de novo vertebrate transcriptome assembly. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:95-101. [PMID: 21651990 PMCID: PMC3223268 DOI: 10.1016/j.cbpc.2011.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [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: 02/10/2011] [Revised: 05/20/2011] [Accepted: 05/24/2011] [Indexed: 12/01/2022]
Abstract
For many researchers, next generation sequencing data holds the key to answering a category of questions previously unassailable. One of the important and challenging steps in achieving these goals is accurately assembling the massive quantity of short sequencing reads into full nucleic acid sequences. For research groups working with non-model or wild systems, short read assembly can pose a significant challenge due to the lack of pre-existing EST or genome reference libraries. While many publications describe the overall process of sequencing and assembly, few address the topic of how many and what types of reads are best for assembly. The goal of this project was use real world data to explore the effects of read quantity and short read quality scores on the resulting de novo assemblies. Using several samples of short reads of various sizes and qualities we produced many assemblies in an automated manner. We observe how the properties of read length, read quality, and read quantity affect the resulting assemblies and provide some general recommendations based on our real-world data set.
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Affiliation(s)
- T.I. Garcia
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Y. Shen
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - J. Catchen
- Institute of Neuroscience, University of Oregon, 1425 E. 13 Avenue, Eugene, OR 97403, USA
| | - A. Amores
- Institute of Neuroscience, University of Oregon, 1425 E. 13 Avenue, Eugene, OR 97403, USA
| | - M. Schartl
- Universität Würzburg, Physiologische Chemie I, Biozentrum, Am Hubland, D-97074 Würzburg, Germany
| | - J. Postlethwait
- Institute of Neuroscience, University of Oregon, 1425 E. 13 Avenue, Eugene, OR 97403, USA
| | - R. B. Walter
- Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
- Corresponding Author: Ronald B. Walter, Department of Chemistry and Biochemistry, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA, Phone: (512) 245-0358; Fax: (512) 245-1922,
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115
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Regneri J, Schartl M. Expression regulation triggers oncogenicity of xmrk alleles in the Xiphophorus melanoma system. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:71-80. [PMID: 21527356 DOI: 10.1016/j.cbpc.2011.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [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: 01/31/2011] [Revised: 04/08/2011] [Accepted: 04/12/2011] [Indexed: 11/28/2022]
Abstract
The Xiphophorus melanoma model has gained attention in biomedical research as a genetic model for tumor formation. Melanoma development in interspecific hybrids of Xiphophorus is connected to pigment cell specific overexpression of the mutationally activated receptor tyrosine kinase Xmrk. In purebred fish the oncogenic function of xmrk is suppressed by a so far unknown regulator locus R. To test the hypothesis that R is involved in transcriptional regulation of xmrk and consequently acts upstream of the xmrk signal, we performed a quantitative analysis of xmrk transcript levels in normal and melanoma tissues of different Xiphophorus genotypes carrying either a highly tumorigenic or a non-tumorigenic xmrk allele. Our results demonstrate that expression of the tumorigenic xmrk allele is highly increased in malignant melanomas compared to benign lesions, macromelanophore spots, and healthy skin. Transcription of the non-tumorigenic xmrk allele in pigment cells, in contrast, is not influenced by the presence or absence of R. These findings strongly indicate that differential transcriptional regulation of the xmrk promoter determines the tumorigenic potential of xmrk alleles in the Xiphophorus melanoma system, thereby supporting the hypothesis that R suppresses the oncogenic function of xmrk on the level of transcriptional control.
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Affiliation(s)
- Janine Regneri
- Physiological Chemistry I, University of Würzburg, Biocenter, Am Hubland, 97074 Würzburg, Germany
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116
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Downs KP, Shen Y, Pasquali A, Beldorth I, Savage M, Gallier K, Garcia T, Booth RE, Walter RB. Characterization of telomeres and telomerase expression in Xiphophorus. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:89-94. [PMID: 21619941 PMCID: PMC3208803 DOI: 10.1016/j.cbpc.2011.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [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: 02/17/2011] [Revised: 05/10/2011] [Accepted: 05/11/2011] [Indexed: 12/15/2022]
Abstract
Research investigating telomere lengths and telomerase expression in vertebrates has progressively become important due to the association of these two biological endpoints with cellular aging and cancer in humans. Studies that rely upon the traditional use of laboratory mice have been faced with limitations largely due to inbred mice possessing large telomeres and ubiquitous expression of telomerase. Recently, a number of small fish species have been shown to provide potentially informative models for examining the role of telomeres and telomerase within intact vertebrate animals. Xiphophorus fishes represent a new world live-bearing genus that has not previously been assessed for telomere length or telomerase expression. To add to the knowledge base of telomere and telomerase biology in vertebrates we assessed telomere length and telomerase expression among several species of Xiphophorus. The telomere lengths in several organs (gill, brain, eyes, testis, ovary and liver) in three species (Xiphophorus hellerii, Xiphophorus maculatus, Xiphophorus couchianus) and also in F(1) interspecies hybrids were approximately 2-6 kb. This size was consistent within the same organs of the same species, as well as between species and F(1) hybrids. Despite possessing relatively short telomere lengths compared to humans, the consistency of size among Xiphophorus species and organs may allow experimental detection of telomere shortening. The relative expression of telomerase reverse transcriptase (TERT) was determined by quantitative real-time PCR. Expression levels of TERT was measured in seven organs (ovary, testis, liver, gill, brain, heart, skin) from X. maculatus, X. hellerii and in control and ultraviolet light (UVB) exposed skin samples from X. maculatus, X. hellerii, and F(1) interspecies hybrids. TERT gene expression was significantly higher in ovary and testis, while all other organs showed low relative TERT expression. Detectable increases in TERT expression were found in skin samples upon UVB exposure. Our findings suggest that Xiphophorus may serve as a suitable model for future studies investigating the association of telomere length and telomerase expression in regard to aging and disease.
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Affiliation(s)
| | | | | | | | | | | | | | - Rachell E. Booth
- Corresponding author. , Phone: (512) 245-2327 ; Fax: (512) 245-2374, Department of Chemistry & Biochemistry, 401 CENT, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA
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117
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Tatarenkov A, Lima SMQ, Avise JC. Extreme homogeneity and low genetic diversity in Kryptolebias ocellatus from south-eastern Brazil suggest a recent foundation for this androdioecious fish population. J Fish Biol 2011; 79:2095-2105. [PMID: 22141910 DOI: 10.1111/j.1095-8649.2011.03155.x] [Citation(s) in RCA: 16] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This study documents unexpectedly low levels of intra and interpopulation genetic diversity in Kryptolebias ocellatus, an androdioecious and predominantly self-fertilizing killifish from south-eastern Brazil. This finding generally is inconsistent with the established opinion that the K. ocellatus and K. marmoratus clade originated in this geographic region and later dispersed northward into the Caribbean.
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Affiliation(s)
- A Tatarenkov
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, USA.
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118
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Hartmann N, Reichwald K, Wittig I, Dröse S, Schmeisser S, Lück C, Hahn C, Graf M, Gausmann U, Terzibasi E, Cellerino A, Ristow M, Brandt U, Platzer M, Englert C. Mitochondrial DNA copy number and function decrease with age in the short-lived fish Nothobranchius furzeri. Aging Cell 2011; 10:824-31. [PMID: 21624037 DOI: 10.1111/j.1474-9726.2011.00723.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [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: 12/14/2022] Open
Abstract
Among vertebrates that can be kept in captivity, the annual fish Nothobranchius furzeri possesses the shortest known lifespan. It also shows typical signs of aging and is therefore an ideal model to assess the role of different physiological and environmental parameters on aging and lifespan determination. Here, we used Nothobranchius furzeri to study whether aging is associated with mitochondrial DNA (mtDNA) alterations and changes in mitochondrial function. We sequenced the complete mitochondrial genome of N. furzeri and found an extended control region. Large-scale mtDNA deletions have been frequently described to accumulate in other organisms with age, but there was no evidence for the presence of detectable age-related mtDNA deletions in N. furzeri. However, mtDNA copy number significantly decreased with age in skeletal muscle, brain, liver, skin and dorsal fin. Consistent with this finding, expression of Pgc-1α that encodes a transcriptional coactivator of mitochondrial biogenesis and expression of Tfam and mtSsbp both encoding mtDNA binding factors was downregulated with age. The investigation of possible changes in mitochondrial function revealed that the content of respiratory chain complexes III and IV was reduced in skeletal muscle with age. In addition, ADP-stimulated and succinate-dependent respiration was decreased in mitochondria of old fish. These findings suggest that despite the short lifespan, aging in N. furzeri is associated with a decline in mtDNA copy number, the downregulation of mtDNA-associated genes and an impairment of mitochondrial function.
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MESH Headings
- Aging/genetics
- Aging/metabolism
- Aging/physiology
- Animals
- Cell Respiration
- Cyprinodontiformes/genetics
- Cyprinodontiformes/metabolism
- Cyprinodontiformes/physiology
- DNA Copy Number Variations
- DNA, Mitochondrial/analysis
- DNA, Mitochondrial/genetics
- Electrophoresis, Gel, Two-Dimensional
- Gene Expression Regulation, Developmental
- Genome, Mitochondrial
- Longevity
- Mitochondria/genetics
- Mitochondria/metabolism
- Mitochondria/physiology
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Models, Theoretical
- Muscle, Skeletal/cytology
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/physiology
- Transcription Factors/genetics
- Transcription Factors/metabolism
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Affiliation(s)
- Nils Hartmann
- Department of Molecular Genetics, Leibniz Institute for Age Research-Fritz Lipmann Institute (FLI), Beutenbergstrasse 11, Jena, Germany.
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119
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Gutiérrez ML, García G. A preliminary linkage map using spotted melanic laboratory strains of the livebearing fish Phalloceros caudimaculatus var. reticulata (Cyprinodontiformes: Poeciliidae). J Genet 2011; 90:e66-e71. [PMID: 21873778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- María Laura Gutiérrez
- Sección Genética Evolutiva, Facultad de Ciencias, UdelaR, Iguá 4225, CP 11400 Montevideo, Uruguay
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120
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Rhee JS, Kim BM, Lee CJ, Yoon YD, Lee YM, Lee JS. Bisphenol A modulates expression of sex differentiation genes in the self-fertilizing fish, Kryptolebias marmoratus. Aquat Toxicol 2011; 104:218-229. [PMID: 21632026 DOI: 10.1016/j.aquatox.2011.04.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 04/21/2011] [Accepted: 04/30/2011] [Indexed: 05/30/2023]
Abstract
Endocrine disrupting chemicals (EDCs) have been a major concern in the normal reproduction and development of aquatic organisms. In the teleost, steroid hormones are synthesized via the steroidogenesis pathway, and play a key physiological role in the regulation of gonadal sex differentiation. The protogynous hermaphroditic fish, Kryptolebias marmoratus is the only vertebrate capable of reproducing through internal self-fertilization. To uncover the effect of bisphenol A (BPA) on sex differentiation genes on transcription, we investigated the expression patterns of several sex differentiation-related genes such as dax1, dmrt1, mis, sf1, figlα, StAR and wt1 after BPA exposure with controls (E2 and TMX). In response to 17β-estradiol (E2) exposure, a testis-specific gene, dmrt1 mRNA was down-regulated in the gonad of the secondary male but the expression of the female-specific gene, dax1 mRNA was significantly elevated in the brain and gonad. A high level of StAR mRNA was detected in the brain and gonad of both hermaphrodite and secondary males, suggesting that the elevated expression of dax1 and StAR genes would be involved in E2 exposure. As expected, upon BPA exposure, the dmrt1 and MIS mRNA level decreased in both hermaphrodite and secondary males, while the female-specific gene, figlα mRNA level increased in the gonad of both genders. BPA showed an opposite mode of action on the expression of dax1 (induction, P>0.05) and sf1 mRNA (inhibition, P>0.05) in the brain and gonad against both genders. The sensitivity of dax1 to BPA on expression was relatively high in the secondary male. The wt1 mRNA was up-regulated in most tissues except in the liver of BPA-exposed secondary males. Regarding the time course study, the figlα mRNA level increased at 6 h after BPA exposure. In addition, BPA elevated the expression of StAR, dax1, and wt1 mRNA but repressed sf1 mRNA. In this paper, we demonstrated that BPA may modulate the expression of sex differentiation and steroidogenesis pathway genes, and this finding would provide a better understanding on the modulation of transcription upon BPA exposure in steroidogenesis and sex differentiation in the hermaphroditic fish, K. marmoratus.
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Affiliation(s)
- Jae-Sung Rhee
- Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791, South Korea
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121
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de Bruyn M, Parenti LR, Carvalho GR. Successful extraction of DNA from archived alcohol-fixed white-eye fish specimens using an ancient DNA protocol. J Fish Biol 2011; 78:2074-2079. [PMID: 21651551 DOI: 10.1111/j.1095-8649.2011.02975.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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
A protocol used routinely for rapid ancient DNA extraction was applied to fish tissue archived over 80 years ago. The method proved successful, whereas other extraction protocols failed. Researchers working on DNA from older archived fish samples are encouraged to continue to concentrate their efforts on 'white-eye' specimens, which indicate an alcohol-based fixative and are thus likely to yield viable DNA.
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Affiliation(s)
- M de Bruyn
- Molecular Ecology and Fisheries Genetics Laboratory, Environment Centre for Wales, Biological Sciences, Bangor University, Deiniol Road, Bangor LL57 2UW, UK.
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122
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Doyle CM, Leberg PL, Klerks PL. Heritability of heat tolerance in a small livebearing fish, Heterandria formosa. Ecotoxicology 2011; 20:535-542. [PMID: 21373902 DOI: 10.1007/s10646-011-0624-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/21/2011] [Indexed: 05/30/2023]
Abstract
Climate change is expected to result in an increased occurrence of heat stress. The long-term population-level impact of this stress would be lessened in populations able to genetically adapt to higher temperatures. Adaptation requires the presence of genetically-based variation. At-risk populations may undergo strong declines in population size that lower the amount of genetic variation. The objectives of this study were to quantify the heritability of heat tolerance in populations of the least killifish, Heterandria formosa, and to determine if heritabilities were reduced following a population bottleneck. Heritabilities of heat tolerance were determined for two lines of each of two source populations; two bottlenecked lines (established with one pair of fish) and two regular lines. Heat tolerance was quantified as temperature-at-death (TAD), when fish acclimated at 28 °C were subjected to an increase in water temperature of 2 °C/day. Mid-parent/mean offspring regressions and full-sib analyses were used to estimate the heritability of TAD. Heritability estimates from parent/offspring regressions ranged from 0.185 to 0.462, while those from sib analyses ranged from 0 to 0.324, with an overall estimate of 0.203 (0.230 for the regular lines, 0.168 for bottlenecked ones). Fish from the bottlenecked line from one source population (but not the other) had a lower heritability than did those from the regular line. These results show that the populations tested had some potential for adaptation to elevated water temperatures, and that this potential may be reduced following a population bottleneck. This should not be construed as evidence that natural populations will not suffer negative consequences from global warming; this study only showed that these specific populations have some potential to adapt under a very specific set of conditions.
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Affiliation(s)
- Cathleen M Doyle
- Department of Biology, University of Louisiana at Lafayette, Box 42451, Lafayette, LA 70504-2451, USA
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123
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Zhang Z, Wang Y, Wang S, Liu J, Warren W, Mitreva M, Walter RB. Transcriptome analysis of female and male Xiphophorus maculatus Jp 163 A. PLoS One 2011; 6:e18379. [PMID: 21483681 PMCID: PMC3071723 DOI: 10.1371/journal.pone.0018379] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 03/06/2011] [Indexed: 01/23/2023] Open
Abstract
Background Xiphophorus models are important for melanoma, sex determination and differentiation, ovoviviparity and evolution. To gain a global view of the molecular mechanism(s) whereby gene expression may influence sexual dimorphism in Xiphophorus and to develop a database for future studies, we performed a large-scale transcriptome study. Methodology/Principal Findings The 454-FLX massively parallel DNA sequencing platform was employed to obtain 742,771 and 721,543 reads from 2 normalized cDNA libraries generated from whole adult female and male X. maculatus Jp 163 A, respectively. The reads assembled into 45,538 contigs (here, a "contig" is a set of contiguous sequences), of which, 11,918 shared homology to existing protein sequences. These numbers estimate that the contigs may cover 53% of the total number of Xiphophorus transcriptome. Putative translations were obtained for 11,918 cDNA contigs, of which, 3,049 amino acid sequences contain Pfam domains and 11,064 contigs encode secretory proteins. A total of 3,898 contigs were associated with 2,781 InterPro (IPR) entries and 5,411 contigs with 132 KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. There were 10,446 contigs annotated with 69,778 gene ontology (GO) terms and the three corresponding organizing principles. Fifty-four potential sex differentially expressed genes have been identified from these contigs. Eight and nine of these contigs were confirmed by real-time PCR as female and male predominantly expressed genes respectively. Based on annotation results, 34 contigs were predicted to be differentially expressed in male and female and 17 of them were also confirmed by real-time PCR. Conclusions/Significance This is the first report of an annotated overview of the transcriptome of X. maculatus and identification of sex differentially expressed genes. These data will be of interest to researchers using the Xiphophorus model. This work also provides an archive for future studies in molecular mechanisms of sexual dimorphism and evolution, and can be used in comparative studies of other fish.
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Affiliation(s)
- Ziping Zhang
- Department of Chemistry and Biochemistry, Molecular Biosciences Research Group, Texas State University, San Marcos, Texas, United States of America
| | - Yilei Wang
- Key Laboratory of Science and Technology for Aquaculture and Food Safety of Fujian Province University, Fisheries College/Fisheries Biotechnology Institute, Jimei University, Xiamen, China
| | - Shuhong Wang
- Key Laboratory of Science and Technology for Aquaculture and Food Safety of Fujian Province University, Fisheries College/Fisheries Biotechnology Institute, Jimei University, Xiamen, China
| | - Jingtao Liu
- Department of Chemistry and Biochemistry, Molecular Biosciences Research Group, Texas State University, San Marcos, Texas, United States of America
| | - Wesley Warren
- Genome Sequencing Center, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Makedonka Mitreva
- Genome Sequencing Center, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Ronald B. Walter
- Department of Chemistry and Biochemistry, Molecular Biosciences Research Group, Texas State University, San Marcos, Texas, United States of America
- * E-mail:
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124
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Rinner BP, Matson CW, Islamzadeh A, McDonald TJ, Donnelly KC, Bickham JW. Evolutionary toxicology: contaminant-induced genetic mutations in mosquitofish from Sumgayit, Azerbaijan. Ecotoxicology 2011; 20:365-376. [PMID: 21312027 DOI: 10.1007/s10646-010-0587-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/18/2010] [Indexed: 05/30/2023]
Abstract
This study builds on a long-term program that has shown Sumgayit, Azerbaijan to contain wetlands with high levels of a diversity of chemical contaminants. Previous contaminant and biomarker studies of turtles and frogs showed a correlation between somatic chromosomal damage and chemical contaminants at Sumgayit. The objective of this study was to determine if a recently arrived species (mosquitofish) has genetic impacts similar to native species (marsh frogs) thus confirming the pattern is not the result of historical events such as glacial cycles, but is associated with recent chemical contamination. Nucleotide sequences of the mtDNA control region of invasive mosquitofish (Gambusia holbrooki) from Sumgayit were compared to mosquitofish from pristine sites in Europe and Azerbaijan and to native North American populations. Persistent heteroplasmy for a hyper-mutable simple sequence repeat and low haplotype and nucleotide diversities were observed in all invasive populations. However, Sumgayit possessed four de novo haplotypes and heteroplasmic conditions. All of the observed variable nucleotide positions were within or adjacent to a cytosine mononucleotide repeat. This repeat was within a conserved secondary structure; the region likely undergoes expansion and contraction at a rate sufficient to prevent fixation of the common 1/3 heteroplasmy. Whereas the 1/3 heteroplasmy appeared coincident with the establishment of mosquitofish in Europe, other forms of heteroplasmy resulted from contaminant-induced de novo mutations in Sumgayit. We conclude that Sumgayit is a mutational hotspot caused by legacy contaminants from chemical factories from the era of the Soviet Union.
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Affiliation(s)
- Brian P Rinner
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
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125
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Boto L, Domínguez-Domínguez O, Doadrio I. Exploring the effect of microsatellite size homoplasy on reconstruction of phylogenetic relationships of picote splitfin Zoogoneticus quitzeoensis. J Fish Biol 2011; 78:673-679. [PMID: 21284645 DOI: 10.1111/j.1095-8649.2010.02877.x] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study explores the effects of microsatellite size homoplasies on the reconstruction of phylogenetic relationships and estimates of population parameters as the fixation index (F(ST) ) using as a case study a truncated microsatellite from the picote splitfin Zoogoneticus quitzeoensis. The results suggest that the use of imperfect microsatellites may have only a minor effect in phylogenetic and population studies.
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Affiliation(s)
- L Boto
- Departamento Biodiversidad y Biología Evolutiva, Museo Nacional Ciencias Naturales, CSIC, C/ José Gutiérrez Abascal 2, Madrid, Spain.
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126
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Abstract
The handicap theory of sexual selection posits that male display traits that are favored in mate choice come at a significant cost to performance. We tested one facet of this hypothesis in the green swordtail (Xiphophorus helleri). In this species, the lower ray of male caudal fin is extended into a 'sword', which serves to attract potential mates. However, bearing a long sword may increase drag and thus compromise a male's ability to swim effectively. We tested escape performance in this species by eliciting C-start escape responses, an instinctive escape behavior, in males with various sword lengths. We then removed males' swords and retested escape performance. We found no relationship between escape performance and sword length and no effect of sword removal on escape performance. While having a large sword may attract a predator's attention, our results suggest that sword size does not compromise a male's escape performance.
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Affiliation(s)
- Alex Baumgartner
- Biology Department, Gonzaga University, Spokane, Washington, United States of America
| | - Seth Coleman
- Biology Department, Gonzaga University, Spokane, Washington, United States of America
| | - Brook Swanson
- Biology Department, Gonzaga University, Spokane, Washington, United States of America
- * E-mail:
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127
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Rhee JS, Kim RO, Chang HH, Lee J, Lee YM, Lee JS. Endocrine disrupting chemicals modulate expression of O⁶-methylguanine DNA methyltransferase (O⁶-MGMT) gene in the hermaphroditic fish, Kryptolebias marmoratus. Comp Biochem Physiol C Toxicol Pharmacol 2011; 153:141-9. [PMID: 20965277 DOI: 10.1016/j.cbpc.2010.10.005] [Citation(s) in RCA: 6] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 10/06/2010] [Accepted: 10/08/2010] [Indexed: 11/29/2022]
Abstract
O⁶-methylguanine-DNA methyltransferase (O⁶-MGMT; EC 2.1.1.63) is a key repair enzyme that helps to protect the cell against alkylation on DNA by removing a methyl group from the O⁶-position of guanine. Here, we cloned and sequenced the full-length O⁶-MGMT cDNA from the hermaphroditic fish, Kryptolebias marmoratus. Complete Km-O⁶-MGMT cDNA was 1324 bp in length, and the open reading frame of 567 bp encoded a polypeptide of 188 amino acid residues. Phylogenetic analysis revealed that Km-O⁶-MGMT was clustered with those of other fish species. Embryo, juveniles, and aged secondary fish had low levels of Km-O⁶-MGMT mRNA than adults, indicating more susceptibility to DNA damage by alkylating agent exposure during these developmental stages. Km-O⁶-MGMT mRNA levels differed according to tissue type and was highest in the liver. Exposure to an alkylating agent, N-methyl-N-nitrosourea (MNU) exposure increased the mRNA expression of tumor suppressor gene such as p53 and oncogenes such as R-ras1, R-ras3, N-ras, c-fos as well as Km-O⁶-MGMT mRNA in a time-dependent manner. On the contrary, several (anti)estrogenic compounds (17β-estradiol 100 ng/L, tamoxifen 10 μg/L, bisphenol A 600 μg/L, and 4-tert-octylphenol 300 μg/L) suppressed mRNA expression of Km-O⁶-MGMT in most tissues, especially the liver. In juvenile fish, 17β-estradiol, bisphenol A, and 4-tert-octylphenol also decreased the expression of Km-O⁶-MGMT mRNA in a time-dependent manner. Overall, our finding shows that Km-O⁶-MGMT mRNA levels can be modulated by environmental estrogenic compounds as well as alkylating agents. This finding will be helpful to improve our knowledge of the effects of estrogenic compounds that contain the genotoxic ability to inhibit the DNA repair process in aquatic animals.
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Affiliation(s)
- Jae-Sung Rhee
- Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791, South Korea
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128
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Rhee JS, Kim RO, Seo JS, Lee J, Lee YM, Lee JS. Effects of salinity and endocrine-disrupting chemicals on expression of prolactin and prolactin receptor genes in the euryhaline hermaphroditic fish, Kryptolebias marmoratus. Comp Biochem Physiol C Toxicol Pharmacol 2010; 152:413-23. [PMID: 20620225 DOI: 10.1016/j.cbpc.2010.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [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: 12/06/2009] [Revised: 07/02/2010] [Accepted: 07/04/2010] [Indexed: 11/15/2022]
Abstract
Prolactin plays an essential role in ion uptake as well as reduction in ion and water permeability of osmoregulatory surfaces in euryhaline fish. Kryptolebias marmoratus is a euryhaline fish with unique internal self-fertilization. In order to understand the effect of different salinities and environmental endocrine-disrupting chemicals (EDCs) on the regulation of prolactin (PRL) and prolactin receptor (PRLR) genes, the full-length sequences of PRL and two PRLR genes were cloned from K. marmoratus. The expression pattern of K. marmoratus PRL (Km-PRL) and PRLR (Km-PRLR1, Km-PRLR2) mRNAs was analyzed in different developmental stages (2dpf to 5h post-hatching) and tissues of hermaphrodite fish. To investigate the effects of salinity changes and EDC exposure, the mRNA expression pattern of PRL, PRLR1 and PRLR2 was analyzed in exposed fish. The Km-PRL mRNA in the hermaphrodite was predominantly expressed in the brain/pituitary, the Km-PRLR1 mRNA was highly expressed in the intestine, while the Km-PRLR2 mRNA was intensively expressed in the gills. The expression of the Km-PRL mRNA generally increased from stage 1 (2 dpf) to stage 3 (12 dpf) in a developmental, stage-dependent manner. It decreased in stage 4 (12 dpf) and the hatching stage (stage 5). Km-PRLR1 and Km-PRLR2 mRNAs showed a gradual increase in expression from stage 1 (2 dpf) to stage 4 (12 dpf) and decreased by stage 5 (5 h post-hatching). Also, both mRNAs of PRLR showed a different expression pattern after exposure to different salinity concentrations (0, 33, and 50 ppt) in juvenile fish. The expression of PRL mRNA was upregulated at 0 ppt, but was downregulated at a moderately higher salinity concentration (33 to 50 ppt). The Km-PRLR1 mRNA showed upregulation at freshwater stress (0 ppt) compared to other concentrations of salinity (33 ppt to 50 ppt). The Km-PRLR2 mRNA was marginally upregulated at freshwater stress (0 ppt), but was downregulated at a higher salinity concentration (50 ppt) and showed no significant change in expression at 33 ppt salinity. Interestingly, both mRNAs showed upregulation in the brain (e.g. Km-PRL) and intestine (e.g. Km-PRLR1) after EDC exposure. These findings suggested that Km-PRL and two Km-PRLR mRNAs would be useful in analyzing the effect of different salinities as well as the modulatory effect of EDC exposure on these gene expressions in K. marmoratus.
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Affiliation(s)
- Jae-Sung Rhee
- Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791, South Korea
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129
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Rhee JS, Kim RO, Seo JS, Kang HS, Park CB, Soyano K, Lee J, Lee YM, Lee JS. Bisphenol A modulates expression of gonadotropin subunit genes in the hermaphroditic fish, Kryptolebias marmoratus. Comp Biochem Physiol C Toxicol Pharmacol 2010; 152:456-66. [PMID: 20647052 DOI: 10.1016/j.cbpc.2010.07.003] [Citation(s) in RCA: 11] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Revised: 07/06/2010] [Accepted: 07/14/2010] [Indexed: 11/23/2022]
Abstract
Pituitary gonadotropins (GTHs), follicle stimulating hormone beta (FSH-beta), and luteinizing hormone beta (LH-beta) are the key hormones in the hypothalamus-pituitary-gonad (HPG) axis, and form the heterodimers between a common alpha subunit (gonadotropin-alpha) and FSH-beta and/or LH-beta. To obtain a better understanding on the modulation of gonadotropin subunit genes expression upon bisphenol A (BPA) exposure in hermaphroditic fish, we studied differential regulation of gonadotropin subunit genes from Kryptolebias marmoratus after the exposure of several EDCs. Expression profiles of these three genes when using quantitative real-time RT-PCR revealed that brain/pituitary tissues were highly expressed in these genes compared to other tissues. At different developmental stages, expression of those genes dramatically increased over the course of development but showed a decrease in expression at the secondary male (showing atresia) stage. When adult fish were exposed to BPA (600 microg/L for 96 h), a significant upregulation of these three genes was observed in the brain/pituitary. A time course study also revealed the increased expression of gonadotropin subunit genes over 12 h with a more pronounced effect on the expression of FSH-beta and LH-beta genes, indicating that both genes were associated with the BPA exposure on the transcriptional regulation. This is the first report of gonadotropin subunit genes from K. marmoratus, with particular emphasis on the modulation of their expressions by EDCs. In addition, these findings suggest that EDCs modulate the expression of gonadotropin subunit genes and would act as potential biomarkers upon EDCs exposure.
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Affiliation(s)
- Jae-Sung Rhee
- Department of Molecular and Environmental Bioscience, Graduate School, Hanyang University, Seoul 133-791, South Korea
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130
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Ternjej I, Mihaljević Z, Stanković I, Kerovec M, Sipos L, Zeljezić D, Kopjar N. Estimation of DNA integrity in blood cells of eastern mosquitofish (Gambusia holbrooki) inhabiting an aluminium-polluted water environment: an alkaline comet assay study. Arch Environ Contam Toxicol 2010; 59:182-193. [PMID: 20098983 DOI: 10.1007/s00244-010-9469-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 01/04/2010] [Indexed: 05/28/2023]
Abstract
To estimate the impacts of an Al-contaminated aquatic environment on DNA integrity in the blood cells of eastern mosquitofish Gambusia holbrooki Girard 1859 inhabiting Lake Njivice (Island of Krk, Croatia), an evaluation using the alkaline comet assay was carried out. Genome integrity was studied in parallel with the same fish species inhabiting the nearby, unpolluted Lake Ponikve. The amount of DNA damage in cells was estimated from three different parameters: comet tail length as the extent of genetic material migration, tail intensity (% DNA in the comet tail) and tail moment. The results indicate the loss of genome integrity in blood cells of mosquitofish inhabiting Lake Njivice and the genotoxicity of this aquatic environment. Using the same assay, acute genotoxicity of contaminated water and sediment was evaluated and confirmed on fish, mouse and human blood cells treated ex vivo. Results of the present study indicate that the alkaline comet assay applied to fish blood cells is a valuable tool for determining the potential genotoxicity of water pollutants and confirm its usefulness in the evaluation of DNA damage in fish living in Al-polluted waters.
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Affiliation(s)
- Ivancica Ternjej
- Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10 000, Zagreb, Croatia.
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131
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Lee JS. Genomic Cloning of a Heat Shock Cognate 71-1 Gene (HSC71-1) from the Hermaphroditic FishRivulus marmoratus(Cyprinodontiformes, Rivulidae). ACTA ACUST UNITED AC 2009; 15:33-8. [PMID: 15354352 DOI: 10.1080/10425170310001659393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [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: 10/26/2022]
Abstract
The self-fertilizing fish Rivulus marmoratus (R. marmoratus) heat shock cognate 71 (HSC71) gene was cloned and characterized recently (Park et al., 2001). Here, we report the isolation of a homologue of the R. marmoratus HSC71 gene via screening of an R. marmoratus genomic DNA library. A 12,591 bp genomic fragment was sequenced and found to contain a 2844 bp open reading frame that consisted of 8 exons and showed high similarity to the previously reported R. marmoratus HSC71 gene. The two genes differed slightly at exons 5 and 8, and intron 3. On a deduced amino acid sequence level, the two R. marmoratus HSC71 genes were highly similar (89.3% in amino acid residues). In this paper, the author presented a homologous gene (R. marmoratus HSC71-1) similar to R. marmoratus HSC71 gene.
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Affiliation(s)
- Jae-Seong Lee
- Department of Environmental Science, Graduate School, Hanyang University, Seoul 133-791, South Korea.
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132
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Affiliation(s)
- Nils Offen
- Department of Biology, Lehrstuhl für Zoologie und Evolutionsbiologie, University of Konstanz, Konstanz, Germany
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133
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Rahn JJ, Trono D, Gimenez-Conti I, Butler AP, Nairn RS. Etiology of MNU-induced melanomas in Xiphophorus hybrids. Comp Biochem Physiol C Toxicol Pharmacol 2009; 149:129-33. [PMID: 18692156 PMCID: PMC2677443 DOI: 10.1016/j.cbpc.2008.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [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: 05/29/2008] [Revised: 07/11/2008] [Accepted: 07/14/2008] [Indexed: 11/24/2022]
Abstract
Genetic hybrids of the genus Xiphophorus have historically been useful models for study of the genetic aspects of tumor formation. In the most studied Xiphophorus tumor model, two-gene loci, XMRK and DIFF, are implicated as critical both to UV-induced and spontaneous melanoma formation in BC(1) hybrids of crosses between X. maculatus and X. helleri, with X. helleri as the recurrent backcross parent. In addition to UV, the direct-acting carcinogen N-methyl-N-nitrosourea (MNU) has been used to induce tumors in Xiphophorus BC(1) hybrids from several cross types. In the present study, we address the hypothesis that excess melanomas in MNU-treated BC(1) hybrids may have been generated by direct mutation of CDKN2AB, a candidate gene for DIFF. MNU treatment of F(1) and BC(1) hybrid fish significantly increased tumor incidence at 6 months; however, no association was found between MNU-induced tumor formation and zygosity of the candidate tumor tumor-suppressor CDKN2AB in BC(1) hybrids, consistent with previously reported results. Sequence analysis of the X. maculatus CDKN2AB locus of heterozygous individuals (both BC(1) and F(1) hybrids) did not reveal any mutations caused by MNU, suggesting that the mechanism of MNU-induced melanoma formation in this Xiphophorus model does not involve direct mutation of CDKN2AB but may result from mutation of other critical genes.
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Affiliation(s)
| | | | | | | | - Rodney S. Nairn
- To whom correspondence should be addressed: UTMDACC, Science Park Research Division, Department of Carcinogenesis, P.O. Box 389, 1808 Park Road 1C, Smithville, TX 78957, USA, Phone: 512-237-9464; Fax: 512-237-2437,
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134
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Yang H, Hazlewood L, Walter RB, Tiersch TR. Sperm cryopreservation of a live-bearing fish, Xiphophorus couchianus: male-to-male variation in post-thaw motility and production of F(1) hybrid offspring. Comp Biochem Physiol C Toxicol Pharmacol 2009; 149:233-9. [PMID: 19027087 PMCID: PMC4532329 DOI: 10.1016/j.cbpc.2008.10.103] [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] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Revised: 10/06/2008] [Accepted: 10/08/2008] [Indexed: 11/24/2022]
Abstract
Fishes of the genus Xiphophorus are well-studied biomedical research models, and some species, such as X. couchianus, are currently listed as endangered in the wild. Sperm cryopreservation in these live-bearing fishes has begun recently. Thus far, live young have been produced with cryopreserved sperm only in one species (Xiphophorus helleri). In this study, the goal was to develop a practical protocol for sperm cryopreservation of Xiphophorus couchianus, and to produce live young with cryopreserved sperm. Sperm were collected by crushing of testis in Hanks' balanced salt solution at an osmolality of 500 mOsmol/kg (HBSS500), and were cryopreserved with 14% glycerol (v/v) as cryoprotectant at a cooling rate of 20 degrees C/min from 5 to -80 degrees C in 250-microL French straws. For artificial insemination, samples were thawed at 40 degrees C for 5 s in a water bath, washed once using fresh HBSS500 by centrifuging at 1000 g for 5 min at 4 degrees C, concentrated into approximately 5 microL, and injected into virgin females of Xiphophorus maculatus. The inseminated females were monitored for 90 days for subsequent discharge of live young. Results from 2006 and 2007 showed considerable male-to-male variation in post-thaw motility (from 1 to 70%). Offspring were produced by cryopreserved sperm in two tanks (of three) at 36 and 66 days after insemination in 2007. Paternity was confirmed via phenotypes (body color) and genotypes (microsatellite genetic marker) of the hybrid offspring. Overall, a practical protocol for sperm cryopreservation and artificial insemination is provided to preserve X. couchianus, which is an important biomedical research model, and also currently listed as an endangered species in the International Union for Conservation of Nature (IUCN) red list.
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Affiliation(s)
- Huiping Yang
- Aquaculture Research Station, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, 2410 Ben Hur Road, Baton Rouge, Louisiana 70820, USA.
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135
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Boswell MG, Wells MC, Kirk LM, Ju Z, Zhang Z, Booth RE, Walter RB. Comparison of gene expression responses to hypoxia in viviparous (Xiphophorus) and oviparous (Oryzias) fishes using a medaka microarray. Comp Biochem Physiol C Toxicol Pharmacol 2009; 149:258-65. [PMID: 19049829 DOI: 10.1016/j.cbpc.2008.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [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: 06/30/2008] [Revised: 11/05/2008] [Accepted: 11/07/2008] [Indexed: 02/02/2023]
Abstract
Gene expression profiling using DNA microarray technology is a useful tool for assessing gene transcript level responses after an organism is exposed to environmental stress. Herein, we detail results from studies using an 8 k medaka (Oryzias latipes) microarray to assess modulated gene expression patterns upon hypoxia exposure of the live-bearing aquaria fish, Xiphophorus maculatus. To assess the reproducibility and reliability of using the medaka array in cross-genus hybridization, a two-factor ANOVA analysis of gene expression was employed. The data show the tissue source of the RNA used for array hybridization contributed more to the observed response of modulated gene targets than did the species source of the RNA. In addition, hierarchical clustering via heat map analyses of groupings of tissues and species (Xiphophorus and medaka) suggests that hypoxia induced similar responses in the same tissues from these two diverse aquatic model organisms. Our Xiphophorus results indicate 206 brain, 37 liver, and 925 gill gene targets exhibit hypoxia induced expression changes. Analysis of the Xiphophorus data to determine those features exhibiting a significant (p<0.05)+/-3 fold change produced only two gene targets within brain tissue and 80 features within gill tissue. Of these 82 characterized features, 39 were identified via homology searching (cut-off E-value of 1 x 10(-5)) and placed into one or more biological process gene ontology groups. Among these 39 genes, metabolic energy changes and manipulation was the most affected biological pathway (13 genes).
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Affiliation(s)
- Mikki G Boswell
- Department of Chemistry and Biochemistry, Molecular Biosciences Research Group, 419 Centennial Hall, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
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136
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Affiliation(s)
- Jerry F Downhower
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, Ohio 43210, USA.
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137
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Langerhans RB, Gifford ME. DIVERGENT SELECTION, NOT LIFE-HISTORY PLASTICITY VIA FOOD LIMITATION, DRIVES MORPHOLOGICAL DIVERGENCE BETWEEN PREDATOR REGIMES INGAMBUSIA HUBBSI. Evolution 2009; 63:561-7. [PMID: 19154366 DOI: 10.1111/j.1558-5646.2008.00556.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R Brian Langerhans
- University of Oklahoma Biological Station and Department of Zoology, University of Oklahoma, HC 71, Box 205, Kingston, Oklahoma 73439, USA.
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138
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Schartl M, Adam D. Molecular cloning, structural characterization, and analysis of transcription of the melanoma oncogene of xiphophorus. Pigment Cell Res 2008; Suppl 2:173-80. [PMID: 1329071 DOI: 10.1111/j.1600-0749.1990.tb00370.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- M Schartl
- Gene Center, Max Planck Institute for Biochemistry, Martinsried, Federal Republic of Germany
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139
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Ward MN, Churcher AM, Dick KJ, Laver CRJ, Owens GL, Polack MD, Ward PR, Breden F, Taylor JS. The molecular basis of color vision in colorful fish: four long wave-sensitive (LWS) opsins in guppies (Poecilia reticulata) are defined by amino acid substitutions at key functional sites. BMC Evol Biol 2008; 8:210. [PMID: 18638376 PMCID: PMC2527612 DOI: 10.1186/1471-2148-8-210] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [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: 01/18/2008] [Accepted: 07/18/2008] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Comparisons of functionally important changes at the molecular level in model systems have identified key adaptations driving isolation and speciation. In cichlids, for example, long wavelength-sensitive (LWS) opsins appear to play a role in mate choice and male color variation within and among species. To test the hypothesis that the evolution of elaborate coloration in male guppies (Poecilia reticulata) is also associated with opsin gene diversity, we sequenced long wavelength-sensitive (LWS) opsin genes in six species of the family Poeciliidae. RESULTS Sequences of four LWS opsin genes were amplified from the guppy genome and from mRNA isolated from adult guppy eyes. Variation in expression was quantified using qPCR. Three of the four genes encode opsins predicted to be most sensitive to different wavelengths of light because they vary at key amino acid positions. This family of LWS opsin genes was produced by a diversity of duplication events. One, an intronless gene, was produced prior to the divergence of families Fundulidae and Poeciliidae. Between-gene PCR and DNA sequencing show that two of the guppy LWS opsins are linked in an inverted orientation. This inverted tandem duplication event occurred near the base of the poeciliid tree in the common ancestor of Poecilia and Xiphophorus. The fourth sequence has been uncovered only in the genus Poecilia. In the guppies surveyed here, this sequence is a hybrid, with the 5' end most similar to one of the tandem duplicates and the 3' end identical to the other. CONCLUSION Enhanced wavelength discrimination, a possible consequence of opsin gene duplication and divergence, might have been an evolutionary prerequisite for color-based sexual selection and have led to the extraordinary coloration now observed in male guppies and in many other poeciliids.
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Affiliation(s)
- Matthew N Ward
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Allison M Churcher
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Kevin J Dick
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Chris RJ Laver
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Greg L Owens
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Megan D Polack
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Pam R Ward
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
| | - Felix Breden
- Simon Fraser University, Department of Biological Sciences, Burnaby, British Columbia, Canada
| | - John S Taylor
- University of Victoria, Department of Biology, Victoria, British Columbia, Canada
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140
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Ritchie MG, Hamill RM, Graves JA, Magurran AE, Webb SA, Macías Garcia C. Sex and differentiation: population genetic divergence and sexual dimorphism in Mexican goodeid fish. J Evol Biol 2007; 20:2048-55. [PMID: 17714321 DOI: 10.1111/j.1420-9101.2007.01357.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [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: 11/29/2022]
Abstract
Genetic differentiation arises due to the interaction between natural and sexual selection, migration and genetic drift. A potential role of sexual selection in speciation has received much interest, although comparative studies are inconsistent in finding supporting evidence. A poorly tested prediction is that species subject to a higher intensity of sexual selection should show greater genetic differentiation amongst populations because females from these populations should be more choosy in mate choice. The Goodeinae is a group of endemic Mexican fishes in which female choice has driven some species to be morphologically sexually dimorphic, whereas others are relatively monomorphic. Here, we measured population divergence, using microsatellite loci, within four goodeid species which show contrasting levels of sexual dimorphism. We found higher levels of differentiation between populations of the more dimorphic species, implying less gene flow between populations. We also found evidence of higher levels of genetic differences between the sexes within populations of the dimorphic species, consistent with greater dispersal in males. Adjusted for geographic distance, the mean F(ST) for the dimorphic species is 0.25 compared with 0.16 for the less dimorphic species. We conclude that population differentiation is accelerated in more sexually dimorphic species, and that comparative phylogeography may provide a more powerful approach to detecting processes, such as an influence of sexual selection on differentiation, than broad-scale comparative studies.
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Affiliation(s)
- M G Ritchie
- School of Biology, University of St Andrews, St Andrews, UK.
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141
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Dadda M, Zandonà E, Bisazza A. Emotional responsiveness in fish from lines artificially selected for a high or low degree of laterality. Physiol Behav 2007; 92:764-72. [PMID: 17631365 DOI: 10.1016/j.physbeh.2007.06.001] [Citation(s) in RCA: 16] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2006] [Revised: 05/15/2007] [Accepted: 06/04/2007] [Indexed: 10/23/2022]
Abstract
Evidence showing that cerebral asymmetries exist in a wide range of animals has prompted investigation into the advantages and disadvantages of brain lateralization. In the teleost fish Girardinus falcatus individuals selected for a high degree of lateralization (LAT) performed better than those fish selected for reduced lateralization (NL) in several tasks, including schooling, foraging and spatial orientation. These findings were interpreted as evidence of hemispheric specialization allowing more efficient parallel processing and thus better cognitive performance under conditions that require multitasking, but the possibility that the results may simply reflect line differences in behavioral/physiological coping styles (i.e. in their emotional responsiveness during the tests) could not be ruled out. To test the hypothesis that NL and LAT fish differ in coping style, the present study examined differences in response in these lines to a novel situation in four different conditions. NL and LAT fish did not differ in a behavioral measure of emotional response: their readiness to explore a new environment. After being isolated in a tight space they showed a similar increase in opercular beating rates, suggesting that their physiological response to an acute stressor was comparable. The overall tendency to remain close to a shoalmate after being moved to an unfamiliar place was similar in the two groups but a significant difference was found in the temporal pattern; LAT fish swam closer than NL to their mirror image in the initial stages but this difference was later reversed. NL and LAT males placed in a new, unfamiliar environment did not differ in the number of sexual acts performed but LAT males resumed sexual behavior earlier signifying that cerebral lateralization has some influence on the trade-off between predator surveillance and mating behavior. Although this study found some differences between NL and LAT lines in their response to novelty, present evidence does not seem sufficient to justify the rejection of the hypothesis that the better scores in complex tasks shown by LAT fish in previous studies were primarily due to a cognitive advantage associated with cerebral specialization.
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Affiliation(s)
- Marco Dadda
- General Psychology Department, Via Venezia 8, 35131, University of Padova, Padova, Via Venezia 8, 35131 Padova, Italy.
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142
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Perkins EJ, Gust KA, Steevens J. Toxicogenomic assessment of the population level impacts of contaminants. Integr Environ Assess Manag 2007; 3:562-564. [PMID: 18046807 DOI: 10.1002/ieam.5630030414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Affiliation(s)
- Edward J Perkins
- US Army Engineer Research and Development Center, Vicksburg, MS, USA.
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143
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Selz Y, Braasch I, Hoffmann C, Schmidt C, Schultheis C, Schartl M, Volff JN. Evolution of melanocortin receptors in teleost fish: The melanocortin type 1 receptor. Gene 2007; 401:114-22. [PMID: 17707598 DOI: 10.1016/j.gene.2007.07.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [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: 05/04/2007] [Revised: 07/04/2007] [Accepted: 07/04/2007] [Indexed: 11/17/2022]
Abstract
The melanocortin type 1 receptor (Mc1r) belongs to a family of G-protein-coupled receptors involved in various physiological processes in vertebrates. Melanocortins, the Mcr natural agonists, are pituitary peptide hormones including adrenocorticotropin and melanocyte-stimulating hormones. In mammals and birds, Mc1r is involved in pigmentation and expressed in melanocytes and melanoma. Activation of Mc1r leads to eumelanin production as well as to proliferation and survival of melanocytes in the epidermis. Here we report the molecular and evolutionary analysis of mc1r from three major fish models, the zebrafish Danio rerio, the medaka Oryzias latipes and the platyfish Xiphophorus maculatus. In contrast to some other melanocortin receptor genes, mc1r has been conserved as a single copy gene in divergent fish species. Its expression was detected in all organs tested in platyfish and medaka but was restricted to eyes, skin, brain and testis in zebrafish, this possibly reflecting differences in the distribution of extracutaneous melanophores. The mc1r gene was found to be expressed during embryogenesis, as well as in Xiphophorus hybrid melanoma, similar to human tumours. Protein sequence comparison between fish and mammalian Mc1r revealed a remarkable concordance between evolutionary and functional analyses for the identification of residues and regions critical for receptor function.
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MESH Headings
- Amino Acid Sequence
- Amino Acid Substitution
- Animals
- Cell Line
- Cloning, Molecular
- Cyprinodontiformes/genetics
- Evolution, Molecular
- Gene Dosage
- Melanocortins/agonists
- Melanocortins/genetics
- Melanocortins/metabolism
- Melanoma, Experimental
- Melanophores/metabolism
- Models, Genetic
- Molecular Sequence Data
- Oryzias/genetics
- Phylogeny
- Protein Structure, Tertiary
- Receptor, Melanocortin, Type 1/chemistry
- Receptor, Melanocortin, Type 1/genetics
- Receptor, Melanocortin, Type 1/metabolism
- Sequence Analysis, Protein
- Sequence Homology, Amino Acid
- Zebrafish/genetics
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Affiliation(s)
- Yvonne Selz
- University of Würzburg, Institute of Physiological Chemistry I, Biozentrum, Am Hubland, D-97074 Würzburg, Germany
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144
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Katsu Y, Hinago M, Sone K, Urushitani H, Guillette LJ, Iguchi T. In vitro assessment of transcriptional activation of the estrogen and androgen receptors of mosquitofish, Gambusia affinis affinis. Mol Cell Endocrinol 2007; 276:10-7. [PMID: 17669586 DOI: 10.1016/j.mce.2007.06.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [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: 03/06/2007] [Revised: 06/11/2007] [Accepted: 06/18/2007] [Indexed: 11/22/2022]
Abstract
Sex-steroid hormones are essential for normal reproductive activity in both sexes. Estrogens are necessary for ovarian differentiation during a critical developmental stage in many vertebrates and promote the growth and differentiation of the female reproductive system. Androgens play essential roles in the development and functioning of the vertebrate male reproductive system as well as actively supporting spermatogenesis. Importantly, recent studies suggest that androgens and estrogens have important reproductive roles in both males and females. To understand the molecular mechanisms of estrogen and androgen actions and to evaluate estrogen and androgen receptor-ligand interactions in the mosquitofish, Gambusia affinis affinis, we used degenerate primer sets and PCR techniques to isolated DNA fragments encoding estrogen receptor alpha (ERalpha; ESR1), ERbeta1 (ERbeta1) and ERbeta2 from the ovary. Full-length mosquitofish ER (mfER) cDNAs were obtained using cDNA library screening and RACE techniques. Amino acid sequences of mfERs showed over-all homology of 46% (alpha versus beta1), 43% (alpha versus beta2), and 52% (beta1 versus beta2). We applied the ERE-luciferase reporter assay system to characterize these receptors. In this transient transfection assay system using mammalian cells, the mfER proteins displayed estrogen-dependent activation of transcription. In addition to ERs, the transactivation of mosquitofish ARs (mfARs) previously isolated by our group, were examined using an androgen-responsive MMTV-luciferase assay system. Mosquitofish ARs showed androgen-dependent activation of transcription from the MMTV promoter. These data provide a basic tool allowing future studies examining the receptor-ligand interactions and endocrine disrupting mechanisms in mosquitofish and also expands our knowledge of estrogen and androgen receptor evolution.
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Affiliation(s)
- Yoshinao Katsu
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki 444-8787, Japan
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145
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Schwab M. Suppression of genetic melanoma in the fish Xiphophorus. Ciba Found Symp 2007; 142:181-97; discussion 197-8. [PMID: 2743831 DOI: 10.1002/9780470513750.ch12] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hybrids between certain species of the teleost Xiphophorus predictably develop melanomas. Classical Mendelian crossing experiments have allowed us to identify genetic loci involved in eliciting and in suppressing tumorigenesis. The overall picture is that melanoma formation results from functional elimination of a suppressor locus allowing abnormal expression of a melanoma locus. Melanoma formation in Xiphophorus behaves like a recessive trait. The fish melanomas consist of incompletely differentiated pigment cells and in many aspects resemble their murine and human counterparts. Cytogenetic studies of cells of the genetic melanomas have provided evidence for chromosomal abnormalities. In particular, cytogenetic manifestations of amplified DNA were detected in a cell line derived from a malignant melanoma. Amplified DNA was isolated and was found to be amplified in a particular type of genetic melanoma. Our results suggest that genetic changes in addition to elimination of suppressor genes contribute to the malignant phenotype of melanoma in Xiphophorus. It is possible that a similar situation occurs in cancers of higher vertebrates, including humans.
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Affiliation(s)
- M Schwab
- Institut für Experimentelle Pathologie, Deutsches Krebsforschungszentrum, Heidelberg, FRG
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146
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Abstract
In contrast to sunlight-induced squamous cell carcinoma the etiology of cutaneous malignant melanoma (CMM) is not well understood. In particular, the role that sunlight exposure and DNA damage play in the initiation of this deadly form of cancer is an open question. Early UV carcinogenesis studies in the Xiphophorus backcross hybrid fish model by Richard Setlow indicated that direct DNA damage caused by exposure to the UVB component of sunlight is necessary and sufficient for melanoma formation. Subsequent studies by Setlow suggested that monochromatic UVA radiation that is not directly absorbed by DNA was also sufficient for melanoma induction in Xiphophorus and was, indeed, primarily responsible for initiating human melanoma. These results had significant public health consequences, suggesting that although sunscreens may inhibit UVB-induced erythema they may actually increase exposure to the UVA wavelengths that cause cancer. An intensive worldwide public debate on sunscreen use and "abuse" ensued. Our data do not support a major role of free radical chemistry in melanoma induction. We find evidence that the direct damage caused by the absorption of UVB wavelengths by DNA (e.g., the cyclobutane pyrimidine dimer or CPD) is required for CMM formation and that the ability to repair these lesions plays a significant role in tumor susceptibility. Using the Xiphophorus backcross hybrid fish we are currently in the process of re-evaluating the wavelength- and DNA damage-dependence of UV-induced melanoma and the role nucleotide excision repair and the genes controlling DNA repair and the UV response play in melanoma resistance. From these studies we hope to define the effective solar wavelength boundaries of melanoma, identify the class of critical DNA damage and elucidate the role of DNA repair in tumor suppression.
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Affiliation(s)
- David Mitchell
- Department of Carcinogenesis, The University of Texas MD Anderson Cancer Center, Science Park/Research Division, Smithville, Texas 78602, USA
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147
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Abstract
Although theory indicates that natural selection can facilitate speciation as a by-product, demonstrating ongoing speciation via this by-product mechanism in nature has proven difficult. We examined morphological, molecular, and behavioral data to investigate ecology's role in incipient speciation for a post-Pleistocene radiation of Bahamas mosquitofish (Gambusia hubbsi) inhabiting blue holes. We show that adaptation to divergent predator regimes is driving ecological speciation as a by-product. Divergence in body shape, coupled with assortative mating for body shape, produces reproductive isolation that is twice as strong between populations inhabiting different predator regimes than between populations that evolved in similar ecological environments. Gathering analogous data on reproductive isolation at the interspecific level in the genus, we find that this mechanism of speciation may have been historically prevalent in Gambusia. These results suggest that speciation in nature can result as a by-product of divergence in ecologically important traits, producing interspecific patterns that persist long after speciation events have completed.
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Affiliation(s)
- R Brian Langerhans
- Department of Biology, Washington University, St. Louis, Missouri 63130, USA.
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148
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Hung CYC, Tsui KNT, Wilson JM, Nawata CM, Wood CM, Wright PA. Rhesus glycoprotein gene expression in the mangrove killifish Kryptolebias marmoratus exposed to elevated environmental ammonia levels and air. J Exp Biol 2007; 210:2419-29. [PMID: 17601945 DOI: 10.1242/jeb.002568] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [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: 01/09/2023]
Abstract
SUMMARY
The mechanism(s) of ammonia excretion in the presence of elevated external ammonia are not well understood in fish. Recent studies in other organisms have revealed a new class of ammonia transporters, Rhesus glycoprotein genes(Rh genes), which may also play a role in ammonia excretion in fish. The first objective of this study was to clone and characterize Rhgenes in a fish species with a relatively high tolerance to environmental ammonia, the mangrove killifish Kryptolebias marmoratus (formerly Rivulus marmoratus). We obtained full-length cDNAs of three Rh genes in K. marmoratus: RhBG (1736 bp), RhCG1 (1920 bp) and RhCG2 (2021 bp), which are highly homologous with other known Rh gene sequences. Hydropathy analysis revealed that all three Rh genes encode membrane proteins with 10–12 predicted transmembrane domains. RhBG, RhCG1 and RhCG2 are highly expressed in gill tissue, with RhBG also present in skin of K. marmoratus. Exposure to elevated environmental ammonia (2 mmol l–1 NH4HCO3) for 5 days resulted in a modest (+37%) increase in whole-body ammonia levels, whereas gill RhCG2 and skin RhCG1 mRNA levels were upregulated by 5.8- and 7.7-fold, respectively. RhBG mRNA levels were also increased in various tissues, with 3- to 7-fold increases in the liver and skeletal muscle. In a separate group of killifish exposed to air for 24 h, RhCG1 and RhCG2 mRNA levels were elevated by 4- to 6-fold in the skin. Thus, the multifold induction of Rh mRNA levels in excretory tissues (gills and skin) and internal tissues in response to conditions that perturb normal ammonia excretion suggests that RhBG, RhCG1 and RhCG2 may be involved in facilitating ammonia transport in this species. Furthermore, the findings support earlier studies demonstrating that the skin is an important site of ammonia excretion in K. marmoratus.
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Affiliation(s)
- C Y C Hung
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
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149
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Vega-López A, Ortiz-Ordóñez E, Uría-Galicia E, Mendoza-Santana EL, Hernández-Cornejo R, Atondo-Mexia R, García-Gasca A, García-Latorre E, Domínguez-López ML. The role of vitellogenin during gestation of Girardinichthys viviparus and Ameca splendens; two goodeid fish with matrotrophic viviparity. Comp Biochem Physiol A Mol Integr Physiol 2007; 147:731-742. [PMID: 17215155 DOI: 10.1016/j.cbpa.2006.10.039] [Citation(s) in RCA: 21] [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] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Revised: 10/23/2006] [Accepted: 10/24/2006] [Indexed: 11/23/2022]
Abstract
Goodeid fish have matrotrophic viviparity, and unlike lecitotrophic fish, yolk loss forces the female to provide the nutritional requirements for embryonic development. Vitellogenin (VTG) is the yolk precursor protein synthesized in the maternal liver, but there is only circumstantial evidence regarding VTG supply during the ontogenesis of bony fish with matrotrophic viviparity. Therefore, the goal of the present study was to identify and quantify VTG during gestation of the black fin goodeid Girardinichthys viviparus and the butterfly split-fin goodeid Ameca splendens. Females at different gonadic developmental stages were selected in order to evaluate VTG mRNA expression in the maternal liver using RT-PCR; VTG quantification in maternal muscle and liver, as well as in the embryos, was done using ELISA, and immunohistochemical detection of VTG was done in the black fin goodeid. The results suggest that VTG supplies nutrients during embryonic development of both species, which have different life histories. It is possible that the transition from lecitotrophy to matrotrophic viviparity in bony fish with intraluminal gestation involved adaptive transition strategies that included changes in the relationship between oocytes and follicular cells, as well as a gradual loss of VTG synthesis during embryonic development.
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Affiliation(s)
- Armando Vega-López
- Laboratorio de Toxicología Acuática, Departamento de Farmacia, Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala s/n, Col. Plutarco Elías Calles "Casco de Santo Tomás". D.F. CP 11340, México.
| | - Esperanza Ortiz-Ordóñez
- Laboratorio de Histología, Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala s/n, Col. Plutarco Elías Calles "Casco de Santo Tomás". D.F. CP 11340, México
| | - Esther Uría-Galicia
- Laboratorio de Histología, Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala s/n, Col. Plutarco Elías Calles "Casco de Santo Tomás". D.F. CP 11340, México
| | - E Laura Mendoza-Santana
- Laboratorio de Histología, Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala s/n, Col. Plutarco Elías Calles "Casco de Santo Tomás". D.F. CP 11340, México
| | - Rubí Hernández-Cornejo
- Laboratorio de Biología Molecular, CIAD Mazatlán, Av. Sábalo Cerritos s/n, Mazatlán Sinaloa. CP 82010, México
| | - Roxana Atondo-Mexia
- Laboratorio de Biología Molecular, CIAD Mazatlán, Av. Sábalo Cerritos s/n, Mazatlán Sinaloa. CP 82010, México
| | - Alejandra García-Gasca
- Laboratorio de Biología Molecular, CIAD Mazatlán, Av. Sábalo Cerritos s/n, Mazatlán Sinaloa. CP 82010, México
| | - Ethel García-Latorre
- Laboratorio de Inmunoquímica I, Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala s/n, Col. Plutarco Elías Calles "Casco de Santo Tomás". D.F. CP 11340, México
| | - Maria Lilia Domínguez-López
- Laboratorio de Inmunoquímica I, Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, IPN. Carpio y Plan de Ayala s/n, Col. Plutarco Elías Calles "Casco de Santo Tomás". D.F. CP 11340, México
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150
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Bisazza A, Dadda M, Facchin L, Vigo F. Artificial selection on laterality in the teleost fish Girardinus falcatus. Behav Brain Res 2007; 178:29-38. [PMID: 17218024 DOI: 10.1016/j.bbr.2006.11.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [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: 06/29/2006] [Revised: 11/25/2006] [Accepted: 11/29/2006] [Indexed: 11/29/2022]
Abstract
We performed five generations of artificial selection on laterality of eye preference in Girardinus falcatus using a detour test. Two lines were selected for right turning when encountering a potential predator, two for left turning, one for no turning bias and one unselected line was used as control. We observed a prompt response to directional selection in all lines and the response was approximately symmetrical in left and right turning lines. However, the response to selection ceased after the first or the second generation and unexpectedly in all lines the average laterality score slowly decreased in subsequent generations. After selection was suspended for three generations, no significant variation in mean laterality was observed in most cases, indicating that natural selection was not actively opposing artificial selection during the experiment. After five generations, selected lines maintained substantial additive variance as evidenced by the possibility of rapidly reversing the direction of laterality bias in just one generation of counter-selection.
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Affiliation(s)
- Angelo Bisazza
- Department of General Psychology, University of Padova, Via Venezia, 8, 35131 Padova, Italy
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