Study On Genetic Variation Of Seven Microsatellites DNA Markers And Their Relationship With Somatic Cell Counts In Cow Milk

The genetic variation (polymorphic information content (PIC), heterozygosity, effective number of alleles and gene frequency) of 7 microsatellite loci (BM1818, BM1258, BM1443, BM1905, BM302, BM4505 and CYP21) was analyzed in 240 cow populations. The results show that PIC, heterozygosity and effective number of alleles of 7 microsatellite loci range from 0.3869 to0.7144,from 0.4348 to 0.7508, from 1.7693 to 4.01249, respectively. Least squares mean of somatic cell counts(SCC) for BM1818 284bp/284bp was significantly lower than those for BM1818 286bp/286bp (P<0.05) in cow populations. The allele 284bp of BM1818 had a significant positive correlation with somatic cell counts in cow populations, the allele 286bp of BM1818 had a significant negative correlation with somatic cell counts in cow populationsï¼›Least squares mean of somatic cell counts for BM1258 100bp/100bp was significantly lower than those for BM1258 102bp /102bp, 106bp/106bp, 106bp/104bp, 106bp/102bp, 106bp/100bp, 104bp/100bp (P<0.05) in cow populations. The allele 100bp of BM1258 had a significant positive correlation with somatic cell counts in cow populations, both alleles 102bp, 104bp and 106bp of BM1258 had a significant negative correlation with somatic cell counts in cow populations; Least squares mean of somatic cell counts for BM1443 166bp/160bp and 166bp/166bp was significantly lower than thoseforBM1443 170bp/160bp, 160bp/157bp, 165bp/160bp (P<0.05) in cow populations. The allele 166bp of BM1443 had a significant positive correlationwith somatic cell counts in cow populations, both alleles 157bp, 165bp, and 170bp of BM1443 had a significant negative correlation with somatic cell counts in cow populations; Least squares mean of somatic cell counts for BM1905 187bp/187bp was significantly lower than thoseforBM1905 197bp/195bp, 193bp/187bp (P<0.05) in cow populations. The allele 187bp of BM1905 had a significant positive correlation with somatic cell counts in cow populations, the allele 193bp of BM1905 had a significant negative correlation with somatic cell counts in cow populationsï¼›Least squares mean of somatic cell counts for BM302 142bp/140bp was significantly lower than those for BM302 154bp/145bp, 143bp/143bp (P<0.05) in cow populations. Both alleles 142bp and 140bp of BM302 had a significant positive correlation with somatic cell counts in cow populations, both alleles 143bp and 145bp of BM302 had a significant negative correlation with somatic cell counts in cow populations; Least squares mean of somatic cell counts for BM4505 240bp/236bp was significantly lower than those for BM4505 240bp/238bp, 240bp/239bp, 240bp/219bp, 236bp/219bp, 235bp/219bp (P<0.05) in cow populations. The allele 236bp of BM4505 had a significant positive correlation with somatic cell counts in cow populations, both alleles 239bp,238bp and 219bp of BM4505 had a significant negative correlation with somatic cell counts in cow populations; Least squares mean of somatic cell counts for CYP21 215bp/198bp was significantly lower than other CYP21 genotypes besids 215bp/194bp (P<0.05) in cow populations. The allele 215bp of CYP21 had a significant positive correlation with somatic cell counts in cow populations, both alleles 208bp, 204bp, 198bp, 194bp and 192bp of BM4505 had a significant negative correlation with somatic cell counts in cow populations.