Genetic polymorphisms of fecundity genes in Watish Sudanese desert sheep.

BACKGROUND AND AIM

The Watish sheep is a strain of desert sheep of smaller size compared to other desert sheep ecotypes, and there is anecdotal evidence that it is endowed with high litter size. The present study was designed for screening for polymorphisms in the known fecundity genes (bone morphogenetic protein receptor type 1B A<G in exon 6, bone morphogenetic protein 15 () ( , , , and ) in exon2, growth differentiation factor 9 () - G1 in exon1 and G8 in exon2 and PRLG<A in intron2) and their association with litter size in Watish.

MATERIALS AND METHODS

The study involved 156 Watish ewes of 2-6 years of age, along with data on litter size in the first, second, and third parity from Sinnar state and contiguous Blue Nile State. Genomic DNA was isolated and genotyped using polymerase chain reaction-restriction fragment length polymorphism. Allele and genotype frequencies were calculated by direct counting. Chi-square test for goodness of fit was performed for agreement with Hardy-Weinberg expectations and association testing.

RESULTS

The results demonstrated that all individuals were non-carriers for the target mutations of , ( , and ), and -G8. With regard to the -G1 gene, the genotypic frequencies were 0.07% (G+) and 0.93% (++), in gene they were 0.993% (++) and 0.006% (B+), in gene 0.516(++), 0.347(B+), and 0.137(BB). The Chi-square test showed a non-significant association between ewe's type of birth and the detected mutations genotypes.

CONCLUSION

These results preliminarily indicated that -G1, ( ), and genes might have had some contribution for improving litter size in Watish Sudanese sheep. However, further studies using larger samples are needed to detect the effects of those mutations on Watish sheep litter size.