Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 19, 2003
Publication Date: June 1, 2004
Citation: Clawson, M.L., Heaton, M.P., Fox, J.M., Chitko Mckown, C.G., Smith, T.P., Laegreid, W.W. 2004. Male-specific SRY and ZFY haplotypes in U.S. beef cattle. Animal Genetics. 35(3):246-249.
Interpretive Summary: The bovine Y chromosome provides a unique target for the sex identification of embryos or other DNA containing samples, and the identification of markers that could assist in the tracking of beef products. A polymerase chain reaction (PCR) assay was developed that detected male DNA from 96 bulls in a multi-breed panel of U.S. beef cattle. The assay did not react with female DNA. Analysis of the gene portion of the Y chromosome targeted for PCR revealed limited genetic diversity between individuals of the multi-breed panel. This indicates that a low number of informative markers may be available in regions of the Y chromosome in U.S. beef cattle.
The sex-determining region of the Y chromosome (SRY) codes for a transcription factor that is critical for testis differentiation. The bovine SRY gene is contained within the non-recombining region of the Y chromosome, and is a target locus for determining the sex and paternal lineage of a DNA sample. A polymerase chain reaction primer pair was designed that produced a 1348 base pair amplicon from 96 bulls representing sixteen beef breeds and one dairy breed. The primer pair did not amplify female DNA. Sequence analysis of the 96 amplicons confirmed the amplification of the SRY locus and identified four single nucleotide polymorphisms (SNPs) with the alleles in perfect linkage disequilibrium (LD). Additionally, the SRY alleles were in perfect LD with those of a previously identified SNP site of the zinc finger Y-linked gene (ZFY) in the same 96 bulls. Consequently, only two Y chromosome haplotypes were identified from combined SRY and ZFY sequence data. These results indicate that a low number of informative markers may be available in regions of the Y chromosome in U.S. beef cattle.