Study On Progesterone Receptor Gene And Bone Morphogenetic Protein 4 Gene And Their Relationship With Goat High Prolificacy

The progesterone receptor(PGR)gene, bone morphogenetic protein 4 (BMP4) gene were studied as candidate genes for the prolificacy in goat in the present study by techniques of PCR single-strand conformational polymorphism (PCR-SSCP) and gene cloning.According to the sequence of bovine PGR gene, fifteen pairs of primers were designed to detect single nucleotide polymorphisms of exon 1 to exon 9 of PGR gene in high prolificacy breed (Jining Grey goat) ,medium prolificacy breeds(Boer goats) and low prolificacy breeds (Inner Mongolia Cashmere and Angora goats) by PCR-SSCP. The products amplified by primers P1, P8 and P9 displayed polymorphisms. For primer P1, three genotypes (AA, AB and BB) were detected in Jining Grey goats, two genotypes (AA and AB) in other goat breeds. Sequencing revealed one mutation (31G→A) of PGR gene in the genotype BB in comparison to the genotype AA, and this mutation resulted in an amino acid change of Ala→Thr. The does with genotype BB had 0.52 (P<0.05) or 0.98 (P<0.001) kids more than those with genotype AB or AA, and the does with genotype AB had 0.46 (P<0.05) kids more than those with genotype AA in Jining Grey goats. For primer P8, only one genotype (CC) was detected in Jining Grey goats, two genotypes (CC and CD) were detected in Boer goats, and three genotypes (CC, CD and DD) were detected in other goat breeds. Sequencing revealed one mutation (2810C→G) of PGR gene in the genotype DD in comparison to the genotype CC, and this mutation did not cause any amino acid change. For primer P9, two genotypes (FF and FG) were detected in Jining Grey and Boer goats, and three genotypes (FF, FG and GG) were detected in other goat breeds. Sequencing revealed one mutation (60128T→A) of PGR gene in the genotype GG in comparison to the genotype FF, and this mutation did not cause any amino acid change. The does with genotype FF had 0.32 (P>0.05) kids more than those with genotype FG in Jining Grey goats. These results preliminarily indicated that the PGR gene is either a major gene that influences the prolificacy in Jining Grey goats or a molecular marker in close linkage with such a gene.According to the sequence of exon2 and intron2 in goat BMP4 gene, two pairs of primers (B1 and B2) were designed to detect single nucleotide polymorphisms of exon 2 and intron 2 of bone morphogenetic protein 4 (BMP4) gene in Jining Grey, Boer, Inner Mongolia Cashmere and Angora goats by PCR-SSCP. Results showed that no polymorphism was detected for exon 2 (primer B1) of BMP4 gene in four goat breeds. For intron 2 (primer B2), three genotypes (EE, EH and HH) were detected in Jining Grey and Inner Mongolia Cashmere goats, two genotypes (EH and HH) in Angora goats, and only one genotype (EE) in Boer goats. Sequencing revealed one mutation (2203G→A) of BMP4 gene in the genotype HH in comparison to the genotype EE. The differences of litter size between EE, EH and HH genotypes were non-significant (P>0.05) in Jining Grey goats. These results preliminarily indicated that the intron2 in BMP4 gene is not a major gene that influences the prolificacy in Jining Grey goats...