Dam construction alters natural flow regimes which,in turn,cause significant changes in fish communities during and after impoundment. The construction of the Three Gorges Reservoir,from impoundment of the Changjiang(...Dam construction alters natural flow regimes which,in turn,cause significant changes in fish communities during and after impoundment. The construction of the Three Gorges Reservoir,from impoundment of the Changjiang(Yangtze) River,China,may have affected native fish species. Thus,the status of two lotic freshwater fish species,Coreius heterodon and C.guichenoti,were monitored in the Three Gorges Reservoir,including fish abundance,individual composition,growth,condition,and mortality. Data on both species were gathered from upstream,midstream and downstream areas of the reservoir and,where available,from studies published before and after dam construction. Lower abundance,slower growth,a less diversified age structure,poorer fish condition(indicated by hepatosomatic index) and higher mortalities were recorded in sites nearest the dam compared with upstream areas. Furthermore,after final impoundment,individual Coreius species inhabiting the area changed,with young individuals becoming more abundant,while upstream of the reservoir the two Coreius species became smaller at a given age. The results show that the status of the two Coreius species was subject to dramatic changes after impoundment.展开更多
The largemouth bronze gudgeon(Coreius guichenoti),an endemic fish species,is distributed in the upper Yangtze River drainage.Due to anthropogenetic factors such as water pollution,overfishing,and dam construction,the ...The largemouth bronze gudgeon(Coreius guichenoti),an endemic fish species,is distributed in the upper Yangtze River drainage.Due to anthropogenetic factors such as water pollution,overfishing,and dam construction,the wild populations of C.guichenoti have dramatically declined in recent decades.In this study,we generated a reference chromosomal-level genome assembly of C.guichenoti on the basis of PacBio HiFi sequencing and Hi-C scaffolding technologies.The final genome assembly was 1.10 Gb in length(contig N50:28.64 Mb;scaffold N50:42.39 Mb)with 25 chromosomes.The completeness score of the C.guichenoti genome was 96.4%,and high synteny was detected compared with Danio rerio and Ictalurus punctatus genomes.A total of 24325 PCGs were annotated for the C.guichenoti genome.Comparative genomics analysis identified 986 expanded gene families in C.guichenoti,which were significantly enriched in GO items associated with the development and interaction of sperm and egg as well as immunity.Furthermore,positively selected genes(PSGs)detected in C.guichenoti were mainly associated with DNA repair,ATP binding,mitochondrion,and lipid homeostasis.Based on the reference genome and resequencing data,the polymorphic microsatellite(SSR)loci were comprehensively analyzed for C.guichenoti,and the top 15 tetra-nucleotide SSR loci were selected for the construction of the genetic maker system after validation through PCR and genotyping.All of these 15 tetra-nucleotide SSR loci without Hardy-Weinberg equilibrium(HWE)deviation showed high polymorphism,good amplification stability,and selective neutrality.The PID(sibs)curves revealed that the subset of four tetra-nucleotide SSR loci(cgui1,cgui5,cgui3,cgui13)was sufficient for accurate identification of C.guichenoti individuals(PIDsib<0.01).These 15 tetra-nucleotide SSR loci could also serve as genetic markers in subsequent parentage identification and genetic diversity analysis.The chromosome-level genome assembly and findings laid solid foundations for molecular breeding,genomic research,and biological conservation of C.guichenoti.展开更多
基金Supported by the National Key Technology Research and Development Program of China(No.2012BAD25B08)the China Three Gorges Corporation Project(No.CT-12-08-01)the State Key Laboratory of Freshwater Ecology and Biotechnology(No.2014FBZ04)
文摘Dam construction alters natural flow regimes which,in turn,cause significant changes in fish communities during and after impoundment. The construction of the Three Gorges Reservoir,from impoundment of the Changjiang(Yangtze) River,China,may have affected native fish species. Thus,the status of two lotic freshwater fish species,Coreius heterodon and C.guichenoti,were monitored in the Three Gorges Reservoir,including fish abundance,individual composition,growth,condition,and mortality. Data on both species were gathered from upstream,midstream and downstream areas of the reservoir and,where available,from studies published before and after dam construction. Lower abundance,slower growth,a less diversified age structure,poorer fish condition(indicated by hepatosomatic index) and higher mortalities were recorded in sites nearest the dam compared with upstream areas. Furthermore,after final impoundment,individual Coreius species inhabiting the area changed,with young individuals becoming more abundant,while upstream of the reservoir the two Coreius species became smaller at a given age. The results show that the status of the two Coreius species was subject to dramatic changes after impoundment.
基金supported by the Postdoctoral Research and Development Fund of Sichuan University(2023SCU12111)the China Postdoctoral Science Foundation(2023M732476).
文摘The largemouth bronze gudgeon(Coreius guichenoti),an endemic fish species,is distributed in the upper Yangtze River drainage.Due to anthropogenetic factors such as water pollution,overfishing,and dam construction,the wild populations of C.guichenoti have dramatically declined in recent decades.In this study,we generated a reference chromosomal-level genome assembly of C.guichenoti on the basis of PacBio HiFi sequencing and Hi-C scaffolding technologies.The final genome assembly was 1.10 Gb in length(contig N50:28.64 Mb;scaffold N50:42.39 Mb)with 25 chromosomes.The completeness score of the C.guichenoti genome was 96.4%,and high synteny was detected compared with Danio rerio and Ictalurus punctatus genomes.A total of 24325 PCGs were annotated for the C.guichenoti genome.Comparative genomics analysis identified 986 expanded gene families in C.guichenoti,which were significantly enriched in GO items associated with the development and interaction of sperm and egg as well as immunity.Furthermore,positively selected genes(PSGs)detected in C.guichenoti were mainly associated with DNA repair,ATP binding,mitochondrion,and lipid homeostasis.Based on the reference genome and resequencing data,the polymorphic microsatellite(SSR)loci were comprehensively analyzed for C.guichenoti,and the top 15 tetra-nucleotide SSR loci were selected for the construction of the genetic maker system after validation through PCR and genotyping.All of these 15 tetra-nucleotide SSR loci without Hardy-Weinberg equilibrium(HWE)deviation showed high polymorphism,good amplification stability,and selective neutrality.The PID(sibs)curves revealed that the subset of four tetra-nucleotide SSR loci(cgui1,cgui5,cgui3,cgui13)was sufficient for accurate identification of C.guichenoti individuals(PIDsib<0.01).These 15 tetra-nucleotide SSR loci could also serve as genetic markers in subsequent parentage identification and genetic diversity analysis.The chromosome-level genome assembly and findings laid solid foundations for molecular breeding,genomic research,and biological conservation of C.guichenoti.
