Novel identification of Factor XI deficiency in Indian Sahiwal (Bos indicus) cattle.

Factor-XI deficiency (FXID) is inherited as autosomal lethal recessive disorder of carrier Holstein-Friesian bulls. A 76 base pair segment insertion into exon 12 in Factor-XI gene causes FXID in cattle. Keeping this in view the present study was conducted to screen breeding bulls of both indigenous and exotic breeds for mutation in Factor-XI gene and to find out the frequency of FXID carrier animals in breeding bulls. A total of 120 bulls of different age group maintained at Frozen Semen Bull Station, India were randomly selected from different cattle breeds to screen presence of FXID syndrome in breeding sires. Genomic DNA was isolated from blood of the selected bulls. PCR parameters were standardized to obtain 244 and 320 bp amplicons. The results showed that 2 Sahiwal bulls out of 120 animals were carrier for FXID. Amplicons of the carrier animals were sequenced and annoted, which confirms a 76 bp insertion in the exon 12. Bleeding and clotting time showed considerable discrepancy in the carrier animals as compared to the normal animals. The findings of relative mRNA expression of Factor XI transcript revealed identical tendency in the carrier. The frequency of carrier animals and mutant allele was 2.5 % and 0.025 respectively. This study recommends for screening of breeding at AI bull centers in the country for FXID. The study also stands a merit for identification of FXID carrier in Bos indicus for the first time.