Equus kiang isolate:ZYL Genome sequencing

Equus species possess widely varying diploid chromosome numbers. Karyotypic diversification is more prominent in Equus species than in other mammals, suggesting that the Equus genus is a promising model for exploring the dynamics of chromosomal evolution. In this study, we address this important gap and report a telomere-to-telomere genome sequence of E. kiang by combination of Illumina short read sequencing, PacBio HiFi reads and Hi-C sequencing. The assembly results show that there are 5 chromosomes without any gaps, and can well predict the telomeres at both ends to realize the T2T assembly of the whole chromosome. In addition, there are 23 chromosomes with less than 5 gaps. These results provide a basis for in-depth analysis of the centromeric sequence characteristics of Equus gunes. The centromeric sequence analysis results showed that in addition to Cen37, 2P1 and EC137, we also found 114bp repeated satellite sequences in the genome of Tibetan wild donkey, which was widely distributed at the end of chromosome. The macro-synteny analysis results showed that at least 13 chromosome recombination events occurred between the genomes of Tibetan wild donkey and horse. High abundance satellite sequences , especially 2P1 satellite sequences were found near the breakpoints of all chromosome recombination. These results suggest that 2P1 may play a key role in chromosomal evolution of Equus genus.