Telomere-to-telomere assemblies of cattle and sheep Y-chromosomes uncover divergent structure and gene content.

Reference genomes of cattle and sheep have lacked contiguous assemblies of the sex-determining Y chromosome. Here, we assemble complete and gapless telomere to telomere (T2T) Y chromosomes for these species. We find that the pseudo-autosomal regions are similar in length, but the total chromosome size is substantially different, with the cattle Y more than twice the length of the sheep Y.

The Ruminant Telomere-to-Telomere (RT2T) Consortium.

Telomere-to-telomere (T2T) assemblies reveal new insights into the structure and function of the previously 'invisible' parts of the genome and allow comparative analyses of complete genomes across entire clades. We present here an open collaborative effort, termed the 'Ruminant T2T Consortium' (RT2T), that aims to generate complete diploid assemblies for numerous species of the Artiodactyla suborder Ruminantia to examine chromosomal evolution in the context of natural selection and domestication of species used as livestock.

The first complete T2T Assemblies of Cattle and Sheep Y-Chromosomes uncover remarkable divergence in structure and gene content.

Reference genomes of cattle and sheep have lacked contiguous assemblies of the sex-determining Y chromosome. We assembled complete and gapless telomere to telomere (T2T) Y chromosomes for these species. The pseudo-autosomal regions were similar in length, but the total chromosome size was substantially different, with the cattle Y more than twice the length of the sheep Y.