Association of Growth Differentiation Factor 9 GDF9 Gene With Some Productive and Reproductive Traits of Some Sudanese Desert Sheep Ecotypes

Abstract The present study was carried out during March and May 2015 at the home-land of the studied desert sheep ecotypes, including Khartoum and Gezira states for (Ashgar and Dubasi sheep), Sinar and Blue Nile states for (Watish and Dubasi sheep) and River Nile state (Ashgar sheep). This study aims to investigate some productive and reproductive traits of some Sudanese desert sheep in different areas in the Sudan, determine the association between live weight and body measurements of Ashgar, Dubasi and Watish sheep using different mathematical models and analyze GDF9 variability and test identified variants for association with litter size among Sudanese desert sheep ecotypes. A total of two hundred and twenty-five head of three sheep ecotypes were randomly selected [80 Ashgar (male=21, female=59), 72 Dubasi (male=22, female=50) and 73 Watish (male=23, female=50)] and according to sex [rams (n=66) and ewes (n=159)] to find out the correlation between live body weight and body measurements using different mathematical models (linear, quadratic, cubic, compound, power and S). The obtained data were tested for significance using analysis of variance ANOVA followed by least significant difference (LSD) test. Also, Independent samples T. test was used and Pearson’s correlation, simple regression analysis was fitted. The live body weight and body measurements were significantly (PA) was genotyped by restriction-length polymorphism analysis in 97 DNA samples. Differences in genotype and allele frequencies of polymorphic positions between two groups differing in litter size (only a single lamb versus more than a single lamb) were tested for significance using Fisher's exact test. GDF9 exon 2 variants c.477G>A and c.721G>A and exon 1 variant c.260G>A were found to be polymorphic in all three sheep ecotypes. Exon 2 variants c.471C>T and c.978 A>G were polymorphic in at least one ecotype. No significant associations were observed between allele and genotype frequencies of identified variants and litter size. This suggests that GDF9 variants influencing ovulation are absent in these Sudanese sheep ecotypes, and therefore cannot be used to increase litter size within this population of sheep.