title: Follicular dynamics and gene expression in granulosa cells, corpora lutea and oocytes from gilts of breeds with low and high ovulation rates.
abstract: Follicular dynamics and the expression of candidate genes using real-time polymerase chain reaction (PCR) were compared during the oestrous cycle of pig breeds with high (commercial line; n=24) and low (local Brazilian Piau; n=21) ovulation rates and prolificacy. Gilts were killed on Days 0, 4, 10 and 18 of the oestrous cycle and visible ovarian follicles were classified by follicular diameter. Recovered cumulus-oocyte complexes were classified as normal or atretic and frozen in liquid nitrogen until RNA extraction. Low ovulation rates and/or prolificacy in Piau gilts was associated with a different pattern of follicle development, with lower numbers of small follicles on Day 18, fewer large follicles on Days 0 and 18 (P≤0.05) and a higher proportion of atretic follicles on Days 0 and 18 (P≤0.05). Compared with commercial line gilts, less-prolific Piau gilts exhibited higher expression of apoptotic genes during luteolysis (CASP3 and FASL; P≤0.05), decreased expression of TGFBR2 and BAX mRNA in the corpus luteum (P≤0.05), higher expression of apoptotic genes (FAS, BCL2 and CASP8; P≤0.05) in granulosa cells and a greater abundance (P≤0.05) of genes controlling oocyte-secreted factors (GDF9, BMP15 and BMP6), suggesting underlying mechanisms controlling differences in follicular development, ovulation rate and inherent prolificacy in this pig breed.
authors: Departamento de Zootecnia, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: P V
authors: PV
authors: Silva
authors: Departamento de Zootecnia, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: S E F
authors: SE
authors: Guimarães
authors: Departamento de Veterinária, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: J D
authors: JD
authors: Guimarães
authors: Departamento de Zootecnia, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: C S
authors: CS
authors: Nascimento
authors: Departamento de Zootecnia, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: P S
authors: PS
authors: Lopes
authors: Departamento de Zootecnia, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: J B
authors: JB
authors: Siqueira
authors: Departamento de Veterinária, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: L S
authors: LS
authors: Amorim
authors: Departamento de Estatística, Universidade Federal de Vicosa, Vicosa 36570-000, MG, Brasil.
authors: F
authors: F
authors: Fonseca E Silva
authors: Swine Reproduction-Development Program, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton T6G 2P5, AB, Canada.
authors: G R
authors: GR
authors: Foxcroft
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D049109:Cell Proliferation; D003338:Corpus Luteum / Q000502:physiology*; D030762:Estrous Cycle / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D006107:Granulosa Cells / Q000502:physiology*; D009865:Oocytes / Q000502:physiology*; D006080:Ovarian Follicle / Q000502:physiology*; D010060:Ovulation / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D034421:Sus scrofa; D013997:Time Factors
chemical_list: D012333:RNA, Messenger