study of mutations available in first-halfexon 2 of gdf9 gene in crossbred sheep born from crossing of romanov rams with kermani ewes

for decreasing the numberofbreedingewes onpastures and prevention of demolition pastures, animal breedingprograms are necessary on genes with major effects on litter size in iranian sheep breeds for identify effective candidate genes on these economical traits .the gdf9 gene is one of the most important effective factors on litter size in sheep. the aim of the present study was to identify g2, g3 and g4 mutations in exon 2 of gdf9 gene in crossbred sheep (romanov rams×kermani ewes) using pcr-sscp. blood samples were collected from jugular vein of 121 crossbred individuals. genomic dna was extracted using salting-out method. partial region of exon 2 (633 bp segments) of gdf9 gene was amplified with designed specific primers. the single stranded conformation polymorphism (sscp) patterns of pcr products were studied using acrylamide gel electrophoresis and silver-nitrate staining method. finally, we obtained 5 banding patterns 1, 2, 3, 4 and 5 with frequencies of 0.314, 0.024, 0.289, 0.232 & 0.141, respectively. the sequencing results showed presence 5 mutations in the studied population.