Vol. 9, Special Issue 8, Part A (2025)

The analysis of transcriptomes has uncovered numerous multi-copy gene families in the MSY region of the bovine Y chromosome. Prior research showed that variations in the copy number of certain genes were associated with bull fertility. Nonetheless, the analysis of copy number for Y-specific genes in Bos indicus breeds has not been explored. Recent research revealed that the copy number of the ZNF280BY gene varied from 28 to 380 in Bos taurus bulls. We examined the CNVs of ZNF280BY in 178 bulls comprising four Bos taurus breeds (HF and Jersey; CBHF and CBJ) and four Bos indicus (Kangayam, Bargur, Umblacherry and Pullikulam) utilizing relative Real time PCR. The single copy gene SRY served as a reference for calculating the multi copy gene, ZNF280BY. All breeds exhibited notable differences in the copy number between individual members. The copy number ranged between 124 and 591, with a median value of 307. In Bos indicus, the Umblacherry breed showed greater levels (Median copy number = 411), while the Bargur breed exhibited lower levels (Median copy number = 263) compared to other breeds. This research presents the copy number variation of ZNF280BY that requires further investigation regarding its relationship with fertility traits in Bos indicus.