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Appraising the Genetic Makeup of an Allochthonous Southern Pike Population: An Opportunity to Predict the Evolution of Introgressive Hybridization in Isolated Populations? Animals (Basel) 2023; 13:ani13030380. [PMID: 36766269 PMCID: PMC9913590 DOI: 10.3390/ani13030380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
Biological invasions are a major threat to the conservation of biodiversity, as invasive species affect native biota through competition, predation, pathogen introduction, habitat alteration, and hybridisation. The present study focuses on a southern pike population, Esox cisalpinus (Teleostei: Esocidae), that has been introduced outside the species' native range. Using microsatellite markers, this study's objective was to gather baseline genetic information and assess the presence of hybrids between this species and E. lucius in the introduced population. The resulting estimates of genetic diversity and effective population size are comparable to those observed in the species' native range. Although different methods yield contrasting and uncertain evidence regarding introgressive hybridization, the presence of late-generation hybrids cannot be completely ruled out. Large numbers of breeders as well as multiple introductions of genetically divergent cohorts and introgressive hybridisation may explain the high genetic diversity of this recently introduced southern pike population. The present study issues a warning that the conservation of southern pike' introgressive hybridisation between northern and southern pike might be underestimated. The genetic information gathered herein may unravel the origin, number of introduction events, and evolutionary trajectory of the introduced population. This information may help us understand the evolution of introgressive hybridisation in the southern pike's native areas.
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Zhong W, Zhang J, Wang Z, Lin J, Huang X, Liu W, Li H, Pellissier L, Zhang X. Holistic Impact Evaluation of Human Activities on the Coastal Fish Biodiversity in the Chinese Coastal Environment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6574-6583. [PMID: 35510674 DOI: 10.1021/acs.est.2c01339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ecological qualities and resources in coasts are threatened by various human activities, such as pollution and fishery. Impact evaluation of environmental stressors over a wide coastal stretch has been limited due to lack of efficient and standardizable biodiversity monitoring and assessment tools. Integrating environmental DNA (eDNA) and ecological traits, a holistic approach was developed to assess the impact of pollution and aquaculture on fish biodiversity in Chinese coastal areas. Taking the Yalujiang Estuary (YLJK) from the Yellow Sea and the Nan'ao Island Area (NAO) from the South China Sea as cases, the performance of the eDNA biomonitoring workflow was validated. First, the eDNA results of 22 sampling sites reached more than 85% of the asymptotes of species or ASVs in each area. A total of 115 fish species in both areas were detected and NAO was 1.8 times richer than YLJK using eDNA and the fish eDNA composition was consistent with the historical data. eDNA recovered distinct variations of fish sequence, taxonomic and functional diversity, and the corresponding trends following the offshore distance between the two areas. Fish sequence diversity was decreased primarily by estuarine pollution factors (chemical oxygen demand and zinc) in the YLJK. Compared with no breeding areas, lower fish sequence diversity was in breeding areas in the NAO. By integrating ecological traits, the eDNA approach offers promising opportunities for future fish biodiversity monitoring and assessment in national and global coastal environments.
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Affiliation(s)
- Wenjun Zhong
- State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Jinyong Zhang
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116023, P. R. China
| | - Zhihao Wang
- State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Jianqing Lin
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou 515063, P. R. China
| | - Xiangyun Huang
- State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Wenhua Liu
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, P. R. China
- Guangdong Provincial Key Laboratory of Marine Biotechnology, Institute of Marine Science, Shantou University, Shantou 515063, P. R. China
| | - Hongjun Li
- State Environmental Protection Key Laboratory of Coastal Ecosystem, National Marine Environmental Monitoring Center, Dalian 116023, P. R. China
| | - Loïc Pellissier
- Swiss Federal Research Institute WSL, Birmensdorf 8903, Switzerland
- Landscape Ecology, Institute of Terrestrial Ecosystems, Department of Environmental System Science, ETH Zürich, Zürich 8092, Switzerland
| | - Xiaowei Zhang
- State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, P. R. China
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Genetic diversity and genetic differentiation of Megalobrama populations inferred by mitochondrial markers. Genes Genomics 2021; 43:1119-1132. [PMID: 34342875 DOI: 10.1007/s13258-021-01126-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 06/16/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Megalobrama is economically one of the most important freshwater fish genera in China. However, phylogenetic relationships among M. amblycephala, M. skolkovii, M. hoffmanni and M. pellegrini remain unresolved. OBJECTIVE To explore the genetic diversity and phylogenetic relationship of Megalobrama populations belonging to all four species. METHODS The concatenated sequences of mitochondrial cytochrome b (Cytb) and control region (CR) were used to analyze the genetic variation, genetic differentiation and population expansion of 15 Megalobrama populations. RESULTS The study showed that haplotype diversity and nucleotide diversity of M. hoffmanni and M. skolkovii were high, and that M. hoffmanni was the most genetically divergent of the four species. Haplotype network analysis revealed that M. hoffmanni and M. amblycephala formed a monophyletic group each, while M. skolkovii and M. pellegrini clustered together. There was a high genetic differentiation among the four Megalobrama species, and genetic distance among populations was not affected by geographical distance. Additionally, the results indicated that there was gene flow between the Liangzi Lake (LZL) population and Jinsha River Reservoir (JS) population. Also, Zhaoqing (ZQ) population of M. hoffmanni might have experienced a population expansion. CONCLUSION Our study verifies genetic diversity and differentiation of Megalobrama populations, and these findings will represent a significant contribution to the conservation and utilization of germplasm resources of Megalobrama.
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Cossu P, Mura L, Scarpa F, Lai T, Sanna D, Azzena I, Fois N, Casu M. Genetic patterns in Mugil cephalus and implications for fisheries and aquaculture management. Sci Rep 2021; 11:2887. [PMID: 33536511 PMCID: PMC7859195 DOI: 10.1038/s41598-021-82515-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 01/18/2021] [Indexed: 01/30/2023] Open
Abstract
Exploitation of fisheries and aquaculture practices are exposing marine fish populations to increasing genetic risks. Therefore, the integration of genetic information into fisheries and aquaculture management is becoming crucial to ensure species' long-term persistence. The raising commercial value of grey mullet (Mugil cephalus) and its roe represents a growing challenge to the sustainable management of this economically important fishery resource. Here, microsatellites were used to investigate patterns of genetic variation in a Mediterranean area that harbor flourishing fisheries and practice semi-intensive farming of grey mullet. Genetic diversity within populations is smaller than values reported in previous studies as a result of the lower polymorphism displayed by the new microsatellite loci. Lack of genetic structuring points to the existence of a unique genetic stock, which is consistent with the species' high dispersal capabilities. Nonetheless, differences in local population effective size as well as the excess of related individuals do not completely fit the picture of a large panmictic population. Baseline genetic information here gathered will allow to set up the genetic monitoring of regional fish stocks, which is needed to assess the impact of both harvesting and aquaculture on the genetic integrity of Mugil cephalus wild populations.
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Affiliation(s)
- Piero Cossu
- grid.11450.310000 0001 2097 9138Department of Sciences for Nature and Environmental Resources, University of Sassari, Sassari, Italy ,grid.11450.310000 0001 2097 9138Department of Veterinary Medicine, University of Sassari, Sassari, SS Italy
| | - Laura Mura
- Dipartimento per la Ricerca Nelle Produzioni Animali, Agris Sardegna, Olmedo, SS Italy
| | - Fabio Scarpa
- grid.11450.310000 0001 2097 9138Department of Sciences for Nature and Environmental Resources, University of Sassari, Sassari, Italy ,grid.11450.310000 0001 2097 9138Department of Veterinary Medicine, University of Sassari, Sassari, SS Italy
| | - Tiziana Lai
- grid.11450.310000 0001 2097 9138Department of Sciences for Nature and Environmental Resources, University of Sassari, Sassari, Italy
| | - Daria Sanna
- grid.11450.310000 0001 2097 9138Department of Sciences for Nature and Environmental Resources, University of Sassari, Sassari, Italy ,grid.11450.310000 0001 2097 9138Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Ilenia Azzena
- grid.11450.310000 0001 2097 9138Department of Veterinary Medicine, University of Sassari, Sassari, SS Italy ,grid.11450.310000 0001 2097 9138Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Nicola Fois
- Dipartimento per la Ricerca Nelle Produzioni Animali, Agris Sardegna, Olmedo, SS Italy
| | - Marco Casu
- grid.11450.310000 0001 2097 9138Department of Sciences for Nature and Environmental Resources, University of Sassari, Sassari, Italy ,grid.11450.310000 0001 2097 9138Department of Veterinary Medicine, University of Sassari, Sassari, SS Italy
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Nayfa MG, Jones DB, Benzie JAH, Jerry DR, Zenger KR. Comparing Genomic Signatures of Selection Between the Abbassa Strain and Eight Wild Populations of Nile Tilapia ( Oreochromis niloticus) in Egypt. Front Genet 2020; 11:567969. [PMID: 33193660 PMCID: PMC7593532 DOI: 10.3389/fgene.2020.567969] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/31/2020] [Indexed: 11/16/2022] Open
Abstract
Domestication to captive rearing conditions, along with targeted selective breeding have genetic consequences that vary from those in wild environments. Nile tilapia (Oreochromis niloticus) is one of the most translocated and farmed aquaculture species globally, farmed throughout Asia, North and South America, and its African native range. In Egypt, a breeding program established the Abbassa Strain of Nile tilapia (AS) in 2002 based on local broodstock sourced from the Nile River. The AS has been intensively selected for growth and has gone through genetic bottlenecks which have likely shifted levels and composition of genetic diversity within the strain. Consequently, there are questions on the possible genetic impact AS escapees may have on endemic populations of Nile tilapia. However, to date there have been no genetic studies comparing genetic changes in the domesticated AS to local wild populations. This study used 9,827 genome-wide SNPs to investigate population genetic structure and signatures of selection in the AS (generations 9–11) and eight wild Nile tilapia populations from Egypt. SNP analyses identified two major genetic clusters (captive and wild populations), with wild populations showing evidence of isolation-by-distance among the Nile Delta and upstream riverine populations. Between genetic clusters, approximately 6.9% of SNPs were identified as outliers with outliers identified on all 22 O. niloticus chromosomes. A lack of localized outlier clustering on the genome suggests that no genes of major effect were presently detected. The AS has retained high levels of genetic diversity (Ho_All = 0.21 ± 0.01; He_All = 0.23 ± 0.01) when compared to wild populations (Ho_All = 0.18 ± 0.01; He_All = 0.17 ± 0.01) after 11 years of domestication and selective breeding. Additionally, 565 SNPs were unique within the AS line. While these private SNPs may be due to domestication signals or founder effects, it is suspected that introgression with blue tilapia (Oreochromis aureus) has occurred. This study highlights the importance of understanding the effects of domestication in addition to wild population structure to inform future management and dissemination decisions. Furthermore, by conducting a baseline genetic study of wild populations prior to the dissemination of a domestic line, the effects of aquaculture on these populations can be monitored over time.
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Affiliation(s)
- Maria G Nayfa
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD, Australia.,Centre for Tropical Bioinformatics and Molecular Biology, College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - David B Jones
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD, Australia.,Centre for Tropical Bioinformatics and Molecular Biology, College of Science and Engineering, James Cook University, Townsville, QLD, Australia
| | - John A H Benzie
- WorldFish, Penang, Malaysia.,School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - Dean R Jerry
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD, Australia.,Centre for Tropical Bioinformatics and Molecular Biology, College of Science and Engineering, James Cook University, Townsville, QLD, Australia.,Tropical Futures Institute, James Cook University, Singapore, Singapore
| | - Kyall R Zenger
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, QLD, Australia.,Centre for Tropical Bioinformatics and Molecular Biology, College of Science and Engineering, James Cook University, Townsville, QLD, Australia
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Comparative Analysis of the Transcriptome and Distribution of Putative SNPs in Two Rainbow Trout ( Oncorhynchus mykiss) Breeding Strains by Using Next-Generation Sequencing. Genes (Basel) 2020; 11:genes11080841. [PMID: 32722051 PMCID: PMC7464081 DOI: 10.3390/genes11080841] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 11/24/2022] Open
Abstract
Selective breeding can significantly improve the establishment of sustainable and profitable aquaculture fish farming. For rainbow trout (Oncorhynchus mykiss), one of the main aquaculture coldwater species in Europe, a variety of selected hatchery strains are commercially available. In this study, we investigated the genetic variation between the local Born strain, selected for survival, and the commercially available Silver Steelhead strain, selected for growth. We sequenced the transcriptome of six tissues (gills, head kidney, heart, liver, spleen, and white muscle) from eight healthy individuals per strain, using RNA-seq technology to identify strain-specific gene-expression patterns and single nucleotide polymorphisms (SNPs). In total, 1760 annotated genes were differentially expressed across all tissues. Pathway analysis assigned them to different gene networks. We also identified a set of SNPs, which are heterozygous for one of the two breeding strains: 1229 of which represent polymorphisms over all tissues and individuals. Our data indicate a strong genetic differentiation between Born and Silver Steelhead trout, despite the relatively short time of evolutionary separation of the two breeding strains. The results most likely reflect their specifically adapted genotypes and might contribute to the understanding of differences regarding their robustness toward high stress and pathogenic challenge described in former studies.
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