title: Influence of the FecX(R) allele in heterozygous ewes on follicular population and outcomes of IVP and ET using LOPU-derived oocytes.
abstract: Ewes heterozygous for the FecX(R) allele (R+) in the bone morphogenetic protein 15 (BMP15) gene display increased ovulation rate and prolificacy. Besides this phenotypic advantage, the influence of the FecX(R) allele on follicle number and size, oocyte competence and in vitro production (IVP) remains undefined. With these aims, 8 R+ and 8 wild-type (++) ewes were subjected to 2 laparoscopic ovum pick-up (LOPU) trials (four sessions per trial; two with and two without FSH) and subsequent IVP and fresh embryo transfer. All follicles >3 mm were punctured (n = 1673). Genotype did not significantly affect the number of punctured follicles per ewe and session (10.4 and 10.2 in R+ and ++ untreated ewes, 17.4 and 14.3 in R+ and ++ FSH-treated ewes, respectively), but follicular diameter of R+ ewes was significantly reduced compared with ++ ewes (-0.2 mm in untreated and -0.8 mm in FSH-treated ewes; p < 0.01). R+ ewes showed higher recovery rate and increased numbers of total and suitable cumulus-oocyte complexes for in vitro maturation (IVM). Similar rates of day 8 blastocysts were observed in R+ (36.1%, 147/407) and ++ (32.6%, 100/307) ewes, but the final output of day 8 blastocysts per ewe and session was higher in R+ ewes (+0.75; p < 0.005), without differences in survival rate at birth of the transferred embryos (40.4%, 21/52 vs 36.4%, 16/44, respectively). In conclusion, a higher number of oocytes proven to be competent for in vitro development and embryo survival after transfer are recovered from R+ ewes, despite the lower mean size of their follicles at puncture.
authors: Centro de Investigación y Tecnología Agroalimentaria (CITA) de Aragón, Zaragoza, Spain.
authors: B
authors: B
authors: Lahoz
authors: J L
authors: JL
authors: Alabart
authors: J
authors: J
authors: Folch
authors: P
authors: P
authors: Sánchez
authors: E
authors: E
authors: Echegoyen
authors: M J
authors: MJ
authors: Cocero
mesh_terms: D000483:Alleles; D000818:Animals; D055430:Bone Morphogenetic Protein 15 / Q000235:genetics*; D003008:Cloprostenol / Q000008:administration & dosage; D004624:Embryo Transfer / Q000662:veterinary*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D003425:Flurogestone Acetate / Q000008:administration & dosage; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage; D006579:Heterozygote; D006728:Hormones / Q000008:administration & dosage; D008186:Luteolytic Agents / Q000008:administration & dosage; D054315:Oocyte Retrieval / Q000662:veterinary; D009865:Oocytes / Q000502:physiology*; D011372:Progestins / Q000008:administration & dosage; D012756:Sheep / Q000235:genetics* / Q000502:physiology
chemical_list: D055430:Bone Morphogenetic Protein 15; D006728:Hormones; D008186:Luteolytic Agents; D011372:Progestins; D003008:Cloprostenol; D005640:Follicle Stimulating Hormone; D003425:Flurogestone Acetate