Telomere-to-telomere Genome Assembly of Equus kiang (Tibetan wild donkey)

The Tibetan wild donkey (Equus kiang) is an endemic equid species inhabiting the Qinghai–Tibet Plateau, exhibiting remarkable chromosomal diversity within the Equus genus. Here we present a chromosome-level, telomere-to-telomere genome assembly for E. kiang generated using Illumina short reads, PacBio HiFi long reads, and Hi-C sequencing data. The final assembly spans 4.02 Gb and comprises 27 pseudochromosomes. Specifically, 8 chromosomes are gapless, 8 chromosomes have one gap, 7 chromosomes have 2–4 gaps, and the remaining 4 chromosomes have five or more gaps. Benchmarking Universal Single-Copy Orthologs (BUSCO) analysis indicated 96.7% completeness, demonstrating high assembly quality. Comparative genome collinearity with the domestic horse (E. caballus) showed that 11 E. kiang chromosomes displayed a simple one-to-one chromosome-scale correspondence. We further characterized genomic features associated with these regions, including the enrichment of tandem repeats near recombination breakpoints. This high-quality genome assembly provides a foundational resource for studies of chromosome evolution, speciation, and genomic architecture in Equus and other mammals.