Analysis of horse genomes provides insight into the diversification and adaptive evolution of karyotype

• Published in: Scientific reports Vol. 4; no. 1; p. 4958
• Main Authors: Huang, Jinlong, Zhao, Yiping, Shiraigol, Wunierfu, Li, Bei, Bai, Dongyi, Ye, Weixing, Daidiikhuu, Dorjsuren, Yang, Lihua, Jin, Burenqiqige, Zhao, Qinan, Gao, Yahan, Wu, Jing, Bao, Wuyundalai, Li, Anaer, Zhang, Yuhong, Han, Haige, Bai, Haitang, Bao, Yanqing, Zhao, Lele, Zhai, Zhengxiao, Zhao, Wenjing, Sun, Zikui, Zhang, Yan, Meng, He, Dugarjaviin, Manglai
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-05-2014; Nature Publishing Group
• Subjects: 45; 45/23; 49; 631/208/211; 631/208/212; Adaptation, Biological; Animals; Biological Evolution; Chromosomes; Computational Biology; Evolution; Evolution & development; Female; Genome; Genomes; Genomics; Heterozygote; High-Throughput Nucleotide Sequencing; Horses; Humanities and Social Sciences; Karyotype; Male; Molecular Sequence Data; multidisciplinary; Recombination, Genetic; Repetitive Sequences, Nucleic Acid; Science; X Chromosomes; Y Chromosome; Y Chromosomes
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep04958

Karyotypic diversification is more prominent in
Equus
species than in other mammals. Here, using next generation sequencing technology, we generated and de novo assembled quality genomes sequences for a male wild horse (Przewalski's horse) and a male domestic horse (Mongolian horse), with about 93-fold and 91-fold coverage, respectively. Portion of Y chromosome from wild horse assemblies (3 M bp) and Mongolian horse (2 M bp) were also sequenced and de novo assembled. We confirmed a Robertsonian translocation event through the wild horse's chromosomes 23 and 24, which contained sequences that were highly homologous with those on the domestic horse's chromosome 5. The four main types of rearrangement, insertion of unknown origin, inserted duplication, inversion and relocation, are not evenly distributed on all the chromosomes and some chromosomes, such as the X chromosome, contain more rearrangements than others and the number of inversions is far less than the number of insertions and relocations in the horse genome. Furthermore, we discovered the percentages of LINE_L1 and LTR_ERV1 are significantly increased in rearrangement regions. The analysis results of the two representative
Equus
species genomes improved our knowledge of
Equus
chromosome rearrangement and karyotype evolution.