Abstract：Abstract： The genetic polymorphism of GlyCAM1 gene in three different breeds (China Holstein cattle, Luxi Yellow cattle, Bohai Black cattle) were studied by CRS-PCR and PCR-SSCP and DNA sequencing. Sequencing results showed that two polymorphic sites were identified at first, which they were at position (A/C) and (C/T) in the GlyCAM1 gene exon3 and intron3 respectively. In the 2081 site the allelic frequencies of A and B were 0.7525/0.2475、0.6112/0.3888、0.3375/0.6625 respectively in China Holstein cattle, Luxi Yellow cattle and Bohai Black cattle. In the 2417 site the allelic frequencies of A and B were 0.9046/0.0954、0.8383/0.1617、0.7875/0.2125 respectively in three different breeds. χ2 test indicated that the polymorphic sites of intron3 were in accordance with the Hardy-Weinberg equilibrium (P>0.05) in the three different breeds. The polymorphic sites of exon3 were in accordance with Hardy-Weinberg equilibrium (P>0.05) in Luxi Yellow cattle and Bohai Black cattle.But it was not in accordance with Hardy-Weinberg equilibrium (P<0.05) in Chinese Holstein cattle.
