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Influence of the Fec X R Allele in Heterozygous Ewes on Follicular Population and Outcomes of IVP and ET using LOPU ‐Derived Oocytes
Author(s) -
Lahoz B,
Alabart JL,
Folch J,
Sánchez P,
Echegoyen E,
Cocero MJ
Publication year - 2013
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/rda.12150
Subject(s) - biology , follicular phase , ovulation , oocyte , population , andrology , endocrinology , embryo transfer , medicine , embryo , zoology , genetics , hormone , environmental health
Contents Ewes heterozygous for the F ec X R allele (R+) in the bone morphogenetic protein 15 ( BMP 15 ) gene display increased ovulation rate and prolificacy. Besides this phenotypic advantage, the influence of the F ec X 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.