title: Porcine growth differentiation factor 9 gene polymorphisms and their associations with litter size.
abstract: Growth differentiation factor 9 (GDF9) is expressed in oocytes and is thought to be required for ovarian folliculogenesis. Given this function, GDF9 may be considered as a candidate gene controlling pig ovulate rate. In this study, the complete coding sequence was cloned (encoding a 444 amino acid), intron sequence and partial 5' -UTR of pig GDF9. RT-PCR results showed that GDF9 mRNA is expressed in a wide range of tissues of the ruttish Erhualian pig. The expression levels of GDF9 mRNA in pituitary, ovary, uterus and oviduct are higher in the Erhualian pigs than those in Duroc pigs, especially in pituitary with a significant difference (P < 0.05). Comparative sequencing revealed 12 polymorphisms, including 8 single nucleotide polymorphisms (SNPs) and one 314 bp indel in noncoding regions, and the other 3 SNPs in coding regions. Four polymorphisms, G359C, C1801T, T1806C and 314 bp indel, were developed as markers for further use in population variation and association studies. The G359C polymorphism segregates only in Chinese native pigs, Erhualian and Dahuabai, on the contrary, 314 bp indel segregates only in Duroc and Landrace. C1801T and T1806C sites seem to be completely linked and segregate in Erhualian, Dahuabai and Landrace. In a word, GDF9 may be not associated with pig litter size in extensive populations as per the studies of allele distributions of the four polymorphisms and pilot association in four breeds.
authors: College of Animal Science, South China Agricultural University, Guangzhou 510642, China.
authors: Yushan
authors: Y
authors: Zhang
authors: Hongli
authors: H
authors: Du
authors: Jing
authors: J
authors: Chen
authors: Guanfu
authors: G
authors: Yang
authors: Xiquan
authors: X
authors: Zhang
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation; D005787:Gene Frequency; D055429:Growth Differentiation Factor 9 / Q000235:genetics*; D008098:Litter Size / Q000235:genetics*; D011110:Polymorphism, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine / Q000235:genetics* / Q000502:physiology*
chemical_list: D018076:DNA, Complementary; D055429:Growth Differentiation Factor 9; D012333:RNA, Messenger