Gonadotrophin stimulation of donor females decreases post-implantation viability of cultured one-cell hamster embryos.
Hamster one-cell embryos were collected from two groups of donors: females that were super-stimulated with pregnant mare's serum gonadotrophin (PMSG) and females that were not. Embryos were cultured for 72 h and scored for development. Morulae and blastocysts from the PMSG- and non-stimulated females were transferred into contralateral uterine horns of non-stimulated recipient females, so that experimental embryos (from PMSG-stimulated females) and control embryos (from non-stimulated females) were paired within a single recipient. Right and left uterine horns of recipient females were examined 11 days later for the number of implantation sites and fetuses. After 72 h of culture, development to morulae and blastocysts was not significantly different for embryos from PMSG- and non-stimulated females. However, embryos from PMSG-stimulated females compared to controls had significantly reduced mean cell numbers (18 versus 21; P=0.003) and a two-fold decrease in viability post-transfer (20 versus 45%; P=0.02). These findings indicate that gonadotrophin stimulation compromises subsequent developmental competence either during oocyte maturation or in the very early embryo, but it is unclear whether reduced viability is a direct effect or is an indirect consequence of PMSG stimulation.
McKiernan
S H
SH
Department of Animal Health and Biomedical Sciences, University of Wisconsin, Madison 53706, USA.
Bavister
B D
BD
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D006224:Cricetinae; D046508:Culture Techniques; D010064:Embryo Implantation; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development; D005260:Female; D006064:Gonadotropins, Equine / Q000009:adverse effects* / Q000494:pharmacology; D009028:Morula / Q000502:physiology; D018587:Oocyte Donation; D011247:Pregnancy; D011256:Pregnancy Outcome
D006064:Gonadotropins, Equine