Genetic polymorphism of Boorola FecB gene and its association with litter size in Balangir, Shahabadi and Bonpala sheep breeds

The aim of this study was to investigate the presence of Boorola FecB mutation gene in 250 selected ewes from different sheep flocks representing Balangir(100), Shahabadi(100) and Bonpala (50) by forced PCR-RFLP method. Genomic DNA was extracted from the blood of Balangir, Shahabadi and Bonpala matured ewes with average litter size varying from 1.00± 0.00 to 1.183± 0.04 at different parities. Digestion of FecB gene with AvaII restriction enzyme resulted FecB^{+ +} in all samples of Balangir and Bonpala but in Shahabadi 76(76%) were FecB^B+ and 24(24%) were FecB^{+ +}. Sequencing of representative samples of FecB gene from each breed showed absence of point mutation i.e., A to G at 110^th position. The overall average of litter size in Balangir, Shahabadi and Bonpala was 1.00± 0.00, 1.41± 0.02 and 1.00± 0.00, respectively. Thus, the association between litter size and FecB^{+ +} genotype among Balangir and Bonpala sheep breeds were in unity. Analysis of variance indicated that the effect of genotype on litter size was highly significant. FecB gene might have introgressed in Shahabadi sheep breed from Garole but the FecB gene has not been fixed in this breed. It needs further introgression of FecB gene through marker assisted introgression, so that each individual animal will lamb twins in future.