Booroola allele segregation in Garole x Malpura sheep

Abstract

Garole sheep of West Bengal (India) is known to carry mutation in an autosomal gene FecB (Booroola allele or FecBB ) on ovine chromosome 6. The mutation is known to affect ovulation rate and in tum litter size in Garole sheep. The mutated allele is hypothesized to be the original genotype ofthe breed and by this virtue the sheep produces twins, triplets and quadruplets. To incorporate the character ofhigher prolificacy in mutton type non-prolific Malpura sheep of semi-arid region ofRajasthan, Garole sheep was used as sire breed in FecB introgression programme started in 1997 at this institute. Presence ofFecB allele was detected in Garole and Garole x Malpura (GM) sheep. The genotypic frequencies for homozygous carriers (FecBBB ) were 0.86 and 0.06 in Garole and OM, respectively. The corresponding figures for heterozygous carriers (FecB B+) were 0.13 and 0.71, respectively. In Garole x Malpura crosses the FecB gene in F1 generation is present in heterozygous state and segregate in homozygous state in F2 and F3generation.