Intensive selection for milk production has led to a reduced reproduction efficiency of high-producing dairy cattle. The first month of pregnancy is associated to a high rate of pregnancy failures. In addition to embryo losses, pre-conceptional status of pregnant females has been reported to affect progeny performance after birth. This study aimed to investigate the impact of the conceptus on endometrium physiology and on peripheral blood leucocytes (PBL) gene expression patterns in a bovine model of contrasted maternal metabolism. Primiparous HolsteinFriesian dairy cows were dried immediately after parturition (DRY) or milked twice daily (LACT). Between 65 and 75 day post-partum, oestrous cycle was synchronized and a single embryo was transferred to each cyclic female at 7 day post-oestrus (dpo). At 19 dpo, blood samples were collected then after slaughter concept were recovered from pregnant females (DRY, n=8 LACT, n=5) and endometrial caruncular (CAR) and intercaruncular areas (ICAR) were dissected from the uterine horn ipsilateral to the corpus luteum. Using total RNA and real-time PCR, we analysed the expression of a selection of genes known to be regulated by the presence of the conceptus (PLET1, SOCS6) and by interferon tau (STAT1,RSAD2, SOCS1, SOCS3) or involved in progesterone (FOXL2, SCARA5) prostaglandin (PTGS2) and oxidative stress (CAT, SOD1,SOD2) molecular pathways. No significant impact of the metabolic status was found on gene expression in PBL. Variance analyses revealed a significant impact of the maternal metabolic status on endometrial genes such as FOXL2 (P<0.002 DRY/LACT fold-ratio=2.1 in CAR and ICAR) and SOD2 (P<0.04 DRY/LACT fold-ratio=0.8 in CAR and ICAR) mRNA expression. Collectively, our findings prompt the need for deciphering the contribution of FOXL2 to endometrial physiology in the context of contrasting metabolic status in dairy cows. Funded by the European X Seventh Framework Programme FP7/2007-2013, grant agreement number 312097 (FECUND).
11 Jul 2016 - 11 Jul 2016