A telomere-to-telomere (T2T) pig genome assembly reveals Y chromosome diversity and structural variations of Wuzhishan pigs

BackgroudWuzhishan (WZS) pigs are native to Hainan Province of China, and serve as both important agricultural resources and biomedical models. Although the published WZS pig genome (T2T-pig1.0) even achieving telomere-to telomere (T2T) completeness, substantial genetic diversity still exists within the same pig breed, another WZS pig genome named WZS-T2T was assembled in this study. ResultsMultiple sequencing data were used to assemble genome, and finally yielded a [~]2.68 Gb telomere-to-telomere genome, with N50 length [~]142.87 Mb, and annotated protein coding genes of 23,100. Compared to T2T-pig1.0, QV and BUSCO value was higher, and the Y chromosome (ChrY) length was longer in WZS-T2T than that of T2T-pig1.0. ChrY of two WZS pigs shared 11 genes, including sex differentiation-related genes of SHOX, PRKX, and DDX3X, and SRY; however, energy metabolism gene SLC25A4 and the macrophage-related receptor gene CSF2RA of ChrY were specific to WZS-T2T. An inversion SV on chromosome 10 with length [~]33.86 Mb was identified between two WZS pigs, and three proofs were proposed for proving the accuracy sequence orientation of WZS-T2T.The genetic diversity was consistent with LD decay speed in population different analysis. WZS pigs exhibited higher genetic diversity than other four pig populations (Tunchang pigs, Yuxi black pigs, Large White pig, and Duroc pigs) examined in this study, and presented slower LD decay compared to other four breeds. ConclusionsTherefore, WZS-T2T provided a higher-quality assembly, and potential advantages of both agricultural production and biomedical targets for WZS pigs.