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Wang B, Wu B, Liu X, Hu Y, Ming Y, Bai M, Liu J, Xiao K, Zeng Q, Yang J, Wang H, Guo B, Tan C, Hu Z, Zhao X, Li Y, Yue Z, Mei J, Jiang W, Yang Y, Li Z, Gao Y, Chen L, Jian J, Du H. Whole-genome Sequencing Reveals Autooctoploidy in Chinese Sturgeon and Its Evolutionary Trajectories. GENOMICS, PROTEOMICS & BIOINFORMATICS 2024; 22:qzad002. [PMID: 38862424 PMCID: PMC11425059 DOI: 10.1093/gpbjnl/qzad002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 06/13/2024]
Abstract
The order Acipenseriformes, which includes sturgeons and paddlefishes, represents "living fossils" with complex genomes that are good models for understanding whole-genome duplication (WGD) and ploidy evolution in fishes. Here, we sequenced and assembled the first high-quality chromosome-level genome for the complex octoploid Acipenser sinensis (Chinese sturgeon), a critically endangered species that also represents a poorly understood ploidy group in Acipenseriformes. Our results show that A. sinensis is a complex autooctoploid species containing four kinds of octovalents (8n), a hexavalent (6n), two tetravalents (4n), and a divalent (2n). An analysis taking into account delayed rediploidization reveals that the octoploid genome composition of Chinese sturgeon results from two rounds of homologous WGDs, and further provides insights into the timing of its ploidy evolution. This study provides the first octoploid genome resource of Acipenseriformes for understanding ploidy compositions and evolutionary trajectories of polyploid fishes.
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Affiliation(s)
- Binzhong Wang
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Bin Wu
- BGI-Shenzhen, Shenzhen 518083, China
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Xueqing Liu
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Yacheng Hu
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Yao Ming
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Mingzhou Bai
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby 2800, Denmark
| | - Juanjuan Liu
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Kan Xiao
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Qingkai Zeng
- River Basin Complex Administration Center, China Three Gorges Corporation, Yichang 443100, China
| | - Jing Yang
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Hongqi Wang
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Baifu Guo
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Chun Tan
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Zixuan Hu
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Xun Zhao
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Yanhong Li
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
| | - Zhen Yue
- BGI-Sanya, BGI-Shenzhen, Sanya 572025, China
| | - Junpu Mei
- BGI-Shenzhen, Shenzhen 518083, China
- BGI-Sanya, BGI-Shenzhen, Sanya 572025, China
| | - Wei Jiang
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Yuanjin Yang
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Zhiyuan Li
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
| | - Yong Gao
- Yangtze Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing 100038, China
| | - Lei Chen
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- River Basin Complex Administration Center, China Three Gorges Corporation, Yichang 443100, China
| | - Jianbo Jian
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby 2800, Denmark
| | - Hejun Du
- Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes, Yichang 443100, China
- Chinese Sturgeon Research Institute, China Three Gorges Corporation, Yichang 443100, China
- Yangtze River Biodiversity Research Center, China Three Gorges Corporation, Wuhan 430014, China
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2
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Iannucci A, Makunin AI, Lisachov AP, Ciofi C, Stanyon R, Svartman M, Trifonov VA. Bridging the Gap between Vertebrate Cytogenetics and Genomics with Single-Chromosome Sequencing (ChromSeq). Genes (Basel) 2021; 12:124. [PMID: 33478118 PMCID: PMC7835784 DOI: 10.3390/genes12010124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/10/2021] [Accepted: 01/15/2021] [Indexed: 01/23/2023] Open
Abstract
The study of vertebrate genome evolution is currently facing a revolution, brought about by next generation sequencing technologies that allow researchers to produce nearly complete and error-free genome assemblies. Novel approaches however do not always provide a direct link with information on vertebrate genome evolution gained from cytogenetic approaches. It is useful to preserve and link cytogenetic data with novel genomic discoveries. Sequencing of DNA from single isolated chromosomes (ChromSeq) is an elegant approach to determine the chromosome content and assign genome assemblies to chromosomes, thus bridging the gap between cytogenetics and genomics. The aim of this paper is to describe how ChromSeq can support the study of vertebrate genome evolution and how it can help link cytogenetic and genomic data. We show key examples of ChromSeq application in the refinement of vertebrate genome assemblies and in the study of vertebrate chromosome and karyotype evolution. We also provide a general overview of the approach and a concrete example of genome refinement using this method in the species Anolis carolinensis.
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Affiliation(s)
- Alessio Iannucci
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy; (C.C.); (R.S.)
| | - Alexey I. Makunin
- Wellcome Sanger Institute, Hinxton CB10 1SA, UK;
- Institute of Molecular and Cellular Biology SB RAS, 630090 Novosibirsk, Russia;
| | - Artem P. Lisachov
- Institute of Environmental and Agricultural Biology (X-BIO), University of Tyumen, 625003 Tyumen, Russia;
- Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
| | - Claudio Ciofi
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy; (C.C.); (R.S.)
| | - Roscoe Stanyon
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy; (C.C.); (R.S.)
| | - Marta Svartman
- Departamento de Genética, Ecologia e Evolução, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, Brazil;
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Biltueva LS, Prokopov DY, Romanenko SA, Interesova EA, Schartl M, Trifonov VA. Chromosome Distribution of Highly Conserved Tandemly Arranged Repetitive DNAs in the Siberian Sturgeon ( Acipenser baerii). Genes (Basel) 2020; 11:E1375. [PMID: 33233736 PMCID: PMC7699875 DOI: 10.3390/genes11111375] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 01/05/2023] Open
Abstract
Polyploid genomes present a challenge for cytogenetic and genomic studies, due to the high number of similar size chromosomes and the simultaneous presence of hardly distinguishable paralogous elements. The karyotype of the Siberian sturgeon (Acipenser baerii) contains around 250 chromosomes and is remarkable for the presence of paralogs from two rounds of whole-genome duplications (WGD). In this study, we applied the sterlet-derived acipenserid satDNA-based whole chromosome-specific probes to analyze the Siberian sturgeon karyotype. We demonstrate that the last genome duplication event in the Siberian sturgeon was accompanied by the simultaneous expansion of several repetitive DNA families. Some of the repetitive probes serve as good cytogenetic markers distinguishing paralogous chromosomes and detecting ancestral syntenic regions, which underwent fusions and fissions. The tendency of minisatellite specificity for chromosome size groups previously observed in the sterlet genome is also visible in the Siberian sturgeon. We provide an initial physical chromosome map of the Siberian sturgeon genome supported by molecular markers. The application of these data will facilitate genomic studies in other recent polyploid sturgeon species.
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Affiliation(s)
- Larisa S. Biltueva
- Institute of Molecular and Cellular Biology SB RAS, Lavrentiev Ave., 8/2, 630090 Novosibirsk, Russia; (L.S.B.); (S.A.R.); (V.A.T.)
| | - Dmitry Yu. Prokopov
- Institute of Molecular and Cellular Biology SB RAS, Lavrentiev Ave., 8/2, 630090 Novosibirsk, Russia; (L.S.B.); (S.A.R.); (V.A.T.)
| | - Svetlana A. Romanenko
- Institute of Molecular and Cellular Biology SB RAS, Lavrentiev Ave., 8/2, 630090 Novosibirsk, Russia; (L.S.B.); (S.A.R.); (V.A.T.)
| | - Elena A. Interesova
- Department of Ichthyology and Hydrobiology, Tomsk State University, Lenin Ave, 36, 634050 Tomsk, Russia;
| | - Manfred Schartl
- Developmental Biochemistry, University of Wuerzburg, Biocenter, Am Hubland, 97074 Wuerzburg, Germany;
- Xiphophorus Genetic Stock Center, Texas State University, 601 University Drive, 419 Centennial Hall, San Marcos, TX 78666-4616, USA
| | - Vladimir A. Trifonov
- Institute of Molecular and Cellular Biology SB RAS, Lavrentiev Ave., 8/2, 630090 Novosibirsk, Russia; (L.S.B.); (S.A.R.); (V.A.T.)
- Novosibirsk State University, Novosibirsk, Pirogova, 2, 630090 Novosibirsk, Russia
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The sterlet sturgeon genome sequence and the mechanisms of segmental rediploidization. Nat Ecol Evol 2020; 4:841-852. [PMID: 32231327 PMCID: PMC7269910 DOI: 10.1038/s41559-020-1166-x] [Citation(s) in RCA: 126] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 02/27/2020] [Indexed: 12/20/2022]
Abstract
Sturgeons seem to be frozen in time. The archaic characteristics of this ancient fish lineage place it in a key phylogenetic position at the base of the ~30,000 modern teleost fish species. Moreover, sturgeons are notoriously polyploid, providing unique opportunities to investigate the evolution of polyploid genomes. We assembled a high-quality chromosome-level reference genome for the sterlet, Acipenser ruthenus. Our analysis revealed a very low protein evolution rate that is at least as slow as in other deep branches of the vertebrate tree, such as that of the coelacanth. We uncovered a whole-genome duplication that occurred in the Jurassic, early in the evolution of the entire sturgeon lineage. Following this polyploidization, the rediploidization of the genome included the loss of whole chromosomes in a segmental deduplication process. While known adaptive processes helped conserve a high degree of structural and functional tetraploidy over more than 180 million years, the reduction of redundancy of the polyploid genome seems to have been remarkably random. A genome assembly of the sterlet, Acipenser ruthenus, reveals a whole-genome duplication early in the evolution of the entire sturgeon lineage and provides details about the rediploidization of the genome.
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Abstract
The diversity of fish hemoglobins and the association with oxygen availability and physiological requirements during the life cycle has attracted scientists since the first report on multiple hemoglobin in fishes (Buhler and Shanks 1959). The functional heterogeneity of the fish hemoglobins enables many species to tolerate hypoxic conditions and exhausting swimming, but also to maintain the gas pressure in the swim bladder at large depths. The hemoglobin repertoire has further increased in various species displaying polymorphic hemoglobin variants differing in oxygen binding properties. The multiplicity of fish hemoglobins as particularly found in the tetraploid salmonids strongly contrasts with the complete loss of hemoglobins in Antarctic icefishes and illustrates the adaptive radiation in the oxygen transport of this successful vertebrate group.
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Affiliation(s)
- Øivind Andersen
- Norwegian Institute of Food, Fisheries and Aquaculture Research (NOFIMA), PO BOX 210,1431, Ås, Norway.
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Cheng P, Huang Y, Du H, Li C, Lv Y, Ruan R, Ye H, Bian C, You X, Xu J, Liang X, Shi Q, Wei Q. Draft Genome and Complete Hox-Cluster Characterization of the Sterlet ( Acipenser ruthenus). Front Genet 2019; 10:776. [PMID: 31543900 PMCID: PMC6739705 DOI: 10.3389/fgene.2019.00776] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 07/23/2019] [Indexed: 01/08/2023] Open
Abstract
Background: Sturgeons (Chondrostei: Acipenseridae) are a group of “living fossil” fishes at a basal position among Actinopteri. They have raised great public interest due to their special evolutionary position, species conservation challenges, as well as their highly-prized eggs (caviar). The sterlet, Acipenser ruthenus, is a relatively small-sized member of sturgeons and has been widely distributing in both Europe and Asia. In this study, we performed whole genome sequencing, de novo assembly and gene annotation of the tarlet to construct its draft genome. Findings: We finally obtained a 1.83-Gb genome assembly (BUSCO completeness of 81.6%) from a total of 316.8-Gb raw reads generated by an Illumina Hiseq 2500 platform. The scaffold N50 and contig N50 values reached 191.06 and 18.88 kb, respectively. The sterlet genome was predicted to be comprised of 42.84% repeated sequences and to contain 22,184 protein-coding genes, of which 21,112 (95.17%) have been functionally annotated with at least one hit in public databases. A genetic phylogeny demonstrated that the sterlet is situated in the basal position among ray-finned fishes and 4dTv analysis estimated that a recent whole genome duplication occurred 21.3 million years ago. Moreover, seven Hox clusters carrying 68 Hox genes were characterized in the sterlet. Phylogeny of HoxA clusters in the sterlet and American paddlefish divided these sturgeons into two groups, confirming the independence of each lineage-specific genome duplication in Acipenseridae and Polyodontidae. Conclusions: This draft genome makes up for the lack of genomic and molecular data of the sterlet and its Hox clusters. It also provides a genetic basis for further investigation of lineage-specific genome duplication and the early evolution of ray-finned fishes.
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Affiliation(s)
- Peilin Cheng
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China.,College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
| | - Yu Huang
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China.,Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Academy of Marine Sciences, BGI Marine, Shenzhen, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Hao Du
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Chuangju Li
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Yunyun Lv
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Academy of Marine Sciences, BGI Marine, Shenzhen, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Rui Ruan
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Huan Ye
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
| | - Chao Bian
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Academy of Marine Sciences, BGI Marine, Shenzhen, China
| | - Xinxin You
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Academy of Marine Sciences, BGI Marine, Shenzhen, China
| | - Junmin Xu
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Academy of Marine Sciences, BGI Marine, Shenzhen, China.,School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan
| | - Xufang Liang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Academy of Marine Sciences, BGI Marine, Shenzhen, China.,BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
| | - Qiwei Wei
- Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan, China
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Sember A, Bohlen J, Šlechtová V, Altmanová M, Pelikánová Š, Ráb P. Dynamics of tandemly repeated DNA sequences during evolution of diploid and tetraploid botiid loaches (Teleostei: Cobitoidea: Botiidae). PLoS One 2018; 13:e0195054. [PMID: 29590207 PMCID: PMC5874072 DOI: 10.1371/journal.pone.0195054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/15/2018] [Indexed: 12/16/2022] Open
Abstract
Polyploidization has played an important role in the evolution of vertebrates, particularly at the base of Teleostei-an enormously successful ray-finned fish group with additional genome doublings on lower taxonomic levels. The investigation of post-polyploid genome dynamics might provide important clues about the evolution and ecology of respective species and can help to decipher the role of polyploidy per se on speciation. Few studies have attempted to investigate the dynamics of repetitive DNA sequences in the post-polyploid genome using molecular cytogenetic tools in fishes, though recent efforts demonstrated their usefulness. The demonstrably monophyletic freshwater loach family Botiidae, branching to evolutionary diploid and tetraploid lineages separated >25 Mya, offers a suited model group for comparing the long-term repetitive DNA evolution. For this, we integrated phylogenetic analyses with cytogenetical survey involving Giemsa- and Chromomycin A3 (CMA3)/DAPI stainings and fluorescence in situ hybridization with 5S/45S rDNA, U2 snDNA and telomeric probes in representative sample of 12 botiid species. The karyotypes of all diploids were composed of 2n = 50 chromosomes, while majority of tetraploids had 2n = 4x = 100, with only subtle interspecific karyotype differences. The exceptional karyotype of Botia dario (2n = 4x = 96) suggested centric fusions behind the 2n reduction. Variable patterns of FISH signals revealed cases of intraspecific polymorphisms, rDNA amplification, variable degree of correspondence with CMA3+ sites and almost no phylogenetic signal. In tetraploids, either additivity or loci gain/loss was recorded. Despite absence of classical interstitial telomeric sites, large blocks of interspersed rDNA/telomeric regions were found in diploids only. We uncovered different molecular drives of studied repetitive DNA classes within botiid genomes as well as the advanced stage of the re-diploidization process in tetraploids. Our results may contribute to link genomic approach with molecular cytogenetic analyses in addressing the origin and mechanism of this polyploidization event.
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Affiliation(s)
- Alexandr Sember
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
| | - Jörg Bohlen
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
| | - Vendula Šlechtová
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
| | - Marie Altmanová
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
- Department of Ecology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic
| | - Šárka Pelikánová
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
| | - Petr Ráb
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, Liběchov, Czech Republic
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8
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Symonová R, Howell WM. Vertebrate Genome Evolution in the Light of Fish Cytogenomics and rDNAomics. Genes (Basel) 2018; 9:genes9020096. [PMID: 29443947 PMCID: PMC5852592 DOI: 10.3390/genes9020096] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/25/2018] [Accepted: 01/29/2018] [Indexed: 12/19/2022] Open
Abstract
To understand the cytogenomic evolution of vertebrates, we must first unravel the complex genomes of fishes, which were the first vertebrates to evolve and were ancestors to all other vertebrates. We must not forget the immense time span during which the fish genomes had to evolve. Fish cytogenomics is endowed with unique features which offer irreplaceable insights into the evolution of the vertebrate genome. Due to the general DNA base compositional homogeneity of fish genomes, fish cytogenomics is largely based on mapping DNA repeats that still represent serious obstacles in genome sequencing and assembling, even in model species. Localization of repeats on chromosomes of hundreds of fish species and populations originating from diversified environments have revealed the biological importance of this genomic fraction. Ribosomal genes (rDNA) belong to the most informative repeats and in fish, they are subject to a more relaxed regulation than in higher vertebrates. This can result in formation of a literal 'rDNAome' consisting of more than 20,000 copies with their high proportion employed in extra-coding functions. Because rDNA has high rates of transcription and recombination, it contributes to genome diversification and can form reproductive barrier. Our overall knowledge of fish cytogenomics grows rapidly by a continuously increasing number of fish genomes sequenced and by use of novel sequencing methods improving genome assembly. The recently revealed exceptional compositional heterogeneity in an ancient fish lineage (gars) sheds new light on the compositional genome evolution in vertebrates generally. We highlight the power of synergy of cytogenetics and genomics in fish cytogenomics, its potential to understand the complexity of genome evolution in vertebrates, which is also linked to clinical applications and the chromosomal backgrounds of speciation. We also summarize the current knowledge on fish cytogenomics and outline its main future avenues.
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Affiliation(s)
- Radka Symonová
- Faculty of Science, Department of Biology, University of Hradec Králové, 500 03 Hradec Králové, Czech Republic.
| | - W Mike Howell
- Department of Biological and Environmental Sciences, Samford University, Birmingham, AL 35229, USA.
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