Associations between fetal size, sex and both proliferation and apoptosis at the porcine feto-maternal interface

Abstract

IntroductionInadequate fetal growth has severe consequences for both neonatal and adult development. It is hypothesised that the feto-maternal interface associated with the lightest and male fetuses will undergo more apoptosis and less proliferation than those supplying the closest to mean litter weight (CTMLW) and female fetuses respectively.MethodsPlacental and endometrial samples associated with the lightest and CTMLW (gestational day (GD) 18 and 30), male and female (GD45, 60 and 90) Large White X Landrace conceptuses or fetuses were obtained. The mRNA expression of candidate genes involved in apoptosis or proliferation (BAX, BCL2, P53 and KI67) was quantified by qPCR. TUNEL staining was performed on placental samples supplying the lightest and CTMLW fetuses (GD45 and 60), of both sex (GD60).ResultsPlacentas associated with the lightest fetuses had decreased P53 and KI67 expression compared to the CTMLW fetuses at GD45. At GD60, P53 expression was increased in placentas supplying the lightest compared to CTMLW fetuses. P53 expression was increased in endometrial samples associated with the lightest compared to the CTMLW fetuses at GD45. At GD30 and GD60 respectively, BAX expression was increased and BCL2, P53 and KI67 expression were decreased in endometrial samples associated with females compared to their male littermates. TUNEL staining revealed no association between fetal size or sex, and apoptotic cell number.DiscussionThis study has highlighted dynamic associations between fetal size, sex, and apoptosis and proliferation at the porcine feto-maternal interface. Further studies should be performed to improve the understanding of the mechanisms behind these findings.

Associations between foetal size and ovarian development in the pig

“…The RNA was extracted from 20 to 50 µg of snapfrozen ovarian samples as described previously (Stenhouse et al, 2019(Stenhouse et al, , 2018a(Stenhouse et al, , 2018b Negative controls without reverse transcriptase were included to assess for genomic contamination and all cDNA was stored at -20ºC until required.…”

Effect of porcine reproductive and respiratory syndrome virus 2 on angiogenesis and cell proliferation at the maternal-fetal interface

“…Finding sex differences was not entirely unexpected as these were reported for angiogenic signaling in tissue of the porcine MFI. 41 Although these previous differences were detected in vitro, it suggests that male and female fetuses communicate differently during different periods of gestation (preimplantation, migrating around the uterus, and implantation). Based on the present results, it is also plausible that male and female fetuses might have differing angiogenic responses when infected by PRRSV.…”

“…The porcine fetomaternal junction (FMJ; including the interdigitating trophoblastic epithelium and uterine epithelium) continually remodels throughout pregnancy through processes of apoptosis, cell proliferation, and angiogenesis to maintain and support fetal development and survival. 39 , 41 , 46 Given the extensive lesions in the MFI following PRRSV infection and the wide variation in fetal outcome, it is possible that alterations in angiogenesis and cell proliferation at the MFI also contribute to fetal outcome. This study aimed to evaluate angiogenesis and cell proliferation in the porcine MFI following maternal PRRSV-2 infection and to determine whether alterations in these processes were associated with variation in fetal resilience.…”

Profiling of open chromatin in developing pig (Sus scrofa) muscle to identify regulatory regions

“…Low birth weight piglets tend to produce fatter, less valuable carcasses from a production perspective and as such their incidence within pig litters should be kept to a minimum ( Pardo et al 2013 ). Size variation within a litter is likely to be determined by many different physiological variables including variation in placental blood flow ( Stenhouse et al 2018 ) but may also be influenced by genetic and epigenetic factors ( Wang et al 2016 ; Li et al 2020 ).…”