CONICET | Buscador de Institutos y Recursos Humanos

Maternal nutrition is the most important component that influences the process of implantationand embryonic development. The objective of this study was to evaluate the effect of nutritionalstatus of donor and recipient sheep on embryo survival and uterine gene expression. The studywas carried out in the Laboratory of Small Ruminants Reproduction of INTA Bariloche duringthe breeding season. Merino donor (n = 36) and recipient (n = 75) sheep were randomlyassigned to two treatment diets, receiving 1.5 (Supplemented, [S]) or 0.5 (Restricted, [R]) timesdaily maintenance requirements during 21 days before recovery and transfer of embryos. Estrussynchronization was performed with intravaginal sponges (Progespon®) for 14 days and an i.madministration of eCG (Novormon®) at time of sponge removal. Donor ewes received thesuperovulatory treatment which consisted in the administration of 100 mg of FSHp (FolltropinV®, Bioniche, Canada) in 6 decreasing doses every 12 hours. Intrauterine artificial inseminationwith frozen semen (100 million spermatozoa) was performed 12 hours after estrus detection. Onday 7 post estrus, embryos were recovered and evaluated from S and R donors and weretransferred by semi-laparoscopy procedure to S and R recipients. Embryo survival rate wasdetermined by ultrasonography on day 22 post embryo transfer. At embryo recovery, biopsieswere obtained from the uterus of donors (n = 26) and recipients (n = 10) and stored in liquid N2until analysis. The uterine gene expression of the receptors of progesterone (PR), insulin growthfactor 1 (IGF-1R) and leptin (LEPR) was determined by real-time PCR. At time of embryotransfer, R donors and recipients had lower uterine gene expression of PR compared with Sdonors and recipients (P