Evaluation of the uterine environment early in pregnancy establishment to characterise cows with a potentially superior ability to support conceptus survival

Abstract

Abstract. During previous investigations, the capacity of the cow to secrete prostaglandin in response to oxytocin has been linked with pregnancy outcome. The objective of the present study was to evaluate the predictive value of prostaglandin release to identify groups of cows as potentially superior (SR, low prostaglandin release) or inferior (IR, high prostaglandin release) for pregnancy outcome and to utilise these cows to investigate factors that contribute to optimum uterine conditions for early pregnancy. Animals were synchronised and received an in vitro-derived blastocyst on Day 7 post-oestrus. Tissues (trophoblast and endometrial) and uterine luminal fluid (ULF) were recovered 10 days later. Pregnancy rates were 94 and 78% for SR and IR cows, respectively. Of the pregnant SR cows, 69% had larged conceptuses (.24 cm) in contrast to 43% IR of cows. IR cows with small conceptuses (,12 cm) had significantly lower mean Day 3 and 5 post-oestrous progesterone concentrations than cows with large conceptuses. The expression of factors involved in the prostaglandin pathway, pregnancy and conceptus development were analysed via quantitative RT-PCR and Western blot analysis. Investigation of 16 endometrial gene transcripts indicated no differences between IR and SR cows except for osteopontin expression which, in uteri with large conceptuses, was 2-fold greater in SR than IR cows (P ¼ 0.02). There was greater expression of CTGF, OXTR, PGES, PGHS2 and UTMP mRNA in uteri of SR and IR cows that had large compared with small conceptuses (P , 0.05). More IFNT protein was recovered in SR compared with IR ULF (P , 0.03). SR cows with large conceptuses had less TIMP2 and legumain protein in their gravid, compared with their non-gravid horns (P # 0.02) whereas IR cows did not. The predictive value of prostaglandin release in response to oxytocin challenge does not appear to be an effective indicator of subsequent pregnancy rates in cows. Differences between the two groups appear to be associated with subtle differences in progesterone and uterine protein concentrations that may be related to differences in conceptus size.

Spatio-specific regulation of endocrine-responsive gene transcription by periovulatory endocrine profiles in the bovine reproductive tract

“…Regarding SERPINA14, it is one of the most abundant proteins present in the pregnant ruminants uterus (Segerson and Bazer 1989). Its main functions are immune modulation and transport of proteins such as immunoglobulins (Ulbrich et al 2009a;Padua and Hansen 2010;Ledgard et al 2011). A previous study (Bauersachs et al 2005) reported that the expression of SERPINA14 is increased at late dioestrus compared with early dioestrus, indicating that the main function of SERPINA14 could be much later during pregnancy.…”

Amino Acids in the Uterine Luminal Fluid Reflects the Temporal Changes in Transporter Expression in the Endometrium and Conceptus during Early Pregnancy in Cattle

“…In cattle, ULF is a prerequisite for development of the embryo beyond the hatched blastocyst stage in vivo, and attempts to artificially induce elongation of bovine conceptuses in vitro have been unsuccessful [9], [10]. The ULF of ruminants is composed of both secreted and transported molecules that include numerous secreted proteins [11], [12], glucose [13], ions [13], fatty acids [14] and amino acids [13], [15]. In sheep, a significant increase in total amino acid content occurs between Days 10 and 16 of pregnancy [13].…”

Transcriptomic Analysis of the Bovine Endometrium: What is Required to Establish Uterine Receptivity to Implantation in Cattle ?

“…Similar classes of genes were identified in another model of fertility where endometrial gene expression was compared between post partum dairy cows with mild (good pregnancy outcome) versus severe (poor pregnancy outcome) negative energy balance. The increased expression of alpha-2-HS-glycoprotein; AHSG, MMP1, MMP3, MMP9 and MMP13 in cows with severe negative energy balance are possible markers of a compromised uterine environment [67], while increased secreted phosphoprotein 1; SPP1 was a marker of reproductive superiority in heifers following an oxytocin challenge in vivo [68]. The use of large-scale transcriptional analysis in these and other studies will continue to allow the detection of an optimal versus a compromised uterine environment.…”