Genetic diversity ofNRAMP13'-UTR microsatellite in cattle breeds reared in Sardinia

The aim of this study was to compare the allele frequency of 3'-UTRNRAMP1(Natural Resistance-Associated Macrophage Protein) microsatellite between local and specialized dairy cattle breeds reared in Sardinia, Italy. Blood samples were collected and DNA was extracted from 97 Sarda, 55 Italian Brown and 36 Italian Friesian cattle and analysed by means of PCR and PCR-SSCP. On the whole, three alleles were found, GT13, GT14, and GT15. GT13showed the highest frequency in all the breeds: 0.874 in the Sarda, 0.973 in the Italian Brown and 1 in the Italian Friesian. For the Sarda, both GT14and GT15showed a frequency of 0.063, while for the Italian Brown 0.018 and 0.009, respectively. Homozygous GT13/GT13was the unique genotype for the Italian Friesian and the most representative for the Italian Brown (0.964) and Sarda (0.823). The other genotypes for the Sarda were: GT14/GT14(0.042), GT13/GT14(0.010), GT13/GT15(0.094) and GT14/GT15(0.031); as regards the Italian Brown, both GT14/GT14and GT13/GT15showed a genotypic frequency of 0.018. The observed heterozygosity was lower than the expected value both for the Sarda and the Italian Brown. Sarda showed a higher genetic variability than Italian Brown and Italian Friesian.