Bone Morphogenetic Protein 15 as a Candidate Gene for Prolificacy of Jining Grey Goat

On the basis of the ovine bone morphogenetic protein 15(BMP15)gene,two pairs of primers(PI and P2)were designed to amplify exons 1 and 2 of the BMP15 gene in five randomly selected does of both Angora and Jining Grey goats.The sequences of BMP15 exon 1(P1 amplification)of Angora and Jining Grey goats were identical.There was a 3-nucleotide(CTT)insertion in positions 268 to 270 of goat BMP 15 exon1 compared with that of sheep(GenBank accession number AF236078),which caused a leucine insertion in the 12th position of amino acid sequence.Sequence length of goat BMP 15 exon 2(P2 amplification)was identical with that of sheep(AF236079),but there were seven nucleotide and four amino acid changes between goat and sheep.The nucleotide in the 963rd position of BMP15 exon 2 was A for Angora goat and sheep,and G for Jining Grey goat.Based on this A963G mutation,primer pair P3 was designed to detect single nucleotide polymorphism of BMP15 exon 2 in breeds of high prolificacy(Jining Grey),moderate prolificacy(Boer)and low prolificacy(Angora and Inner Mongolia Cashmere)by polymerase chain reactionsingle strand conformation polymorphism(PCR-SSCP).Three genotypes(AA,AG and GG)were detected in Jining Grey goats,two genotypes(AG and GG)in Boer,and only the AA genotype in Angora and Inner Mongolia Cashmere goats.Sequencing revealed one mutation(A963G)in genotype GG compared with genotype AA,and this mutation resulted in an amino acid change of serine→glycine(S300G).In Jining Grey goats,frequencies of AA,AG and GG genotypes were 0.008,0.059 and 0.933,respectively.Genotypic distributions of the BMP 15 gene were significantly different(P<0.05 or P<0.001)between Jining Grey and Boer,Angora,and Inner Mongolia Cashmere goats.In Jining Grey goats,the does with the GG genotype had 0.71(P<0.05)or 1.57(P<0.05)additional kids than did those with AG or AA genotypes,and does with the AG genotype had 0.86(P<0.05)more kids than did those with the AA genotype.These results tentatively indicate that the BMP15 gene is either a major gene that affects prolificacy in Jining Grey goats,or may be a molecular marker in close linkage with such a gene.