Identification of Complex Vertebral Malformation Carriers in Holstein and Guilan Native Cow Breeds in Iran Using SSCP Markers

Complex vertebral malformation (CVM) is an autosomal recessive hereditary disorder caused by a point mutation in position 559 in exon 4 of the SLC35A3 gene on chromosome 3 in Holstein dairy cattle. This mutation changes the function of uridine 5-diphosphate-N-acetylglucosamine transporter protein by the substitution of valine for phenylalanine at position 180 of this protein. The disease causes premature birth, aborted fetuses and stillborn calves. Latent recessiveenes in heterozygous individuals can be identified with high accuracy and repeatability using PCR-SSCP technique. In the present study, blood samples from two different cow populations, including 100 Holstein cows and 100 Guilan native cattle were randomly collected. Specific primers were used to amplify the 177-bp fragment of exon 4 of the SLC35A3 gene. No heterozygous genotype was detected in the studied samples. The Lack of carriers could be a consequence of the selection against the defective gene and preventative programs for entering mutant genes into the populations or very low frequency of this gene in these populations. However, there is a risk for increased genetic defects prevalence and it is necessary to develop screening programs to identify the defective gene.