DefinePK

Abstract

The complex vertebral malformation (CVM) syndrome is a congenital autosomal recessively inherited disorder first observed in Danish Holsteins. It is caused by a point mutation (G?T) at nucleotide position 559 of the gene, bovine solute carrier family 35 member 3 (SLC35A3). Bovine SLC35A3 plays a vital role in the development of the axial skeleton. The aim of this study was to detect carriers of CVM in Holstein population using Polymerase Chain Reaction- Primer-introduced restriction analysis and Restriction Fragment Length Polymorphism (PCR-PIRA and RFLP) methods. Our results show that one out of 60 bulls tested exhibited polymorphism (G?T) at position 559 in exon 4 of SLC35A3 gene. To confirm this polymorphism, the PCR product was purified using ExoSAP-IT followed by sequencing by Applied Biosystems 3130XL Automated Sequencer using the ABI BigDye Ver 3.1. Gene sequences from normal and carrier animals were compared using the software, codon code Aligner 4.0.4. Surprisingly, the sequence analysis of PCR product also revealed the presence of two previously unknown homozygous mutations (TG?CT) at nucleotide positions 554 and 555 in addition to the previously reported heterozygous mutation at position 559. The bull was immediately culled from the breeding programme. To the our best of knowledge, this is the first study to report the existence of homozygous and heterozygous mutations at positions 554, 555 and 559 in exon 4 of SLC35A3 gene in Indian Holstein cattle. However, it is surprising that no phenotypic effects were observed in the carrier bull, necessitating further studies to fully elucidate the effects of these novel homozygous mutations.