Project description:Epigenetic changes such as DNA cytosine methylation modulate gene function across brain and are implicated in the pathophysiology of neurodevelopmental disorders including schizophrenia and autism. Epigenetic changes can be caused by environmental exposures such as inflammation, and may at least partly explain why prenatal exposure to inflammation increase risk of neurodevelopmental disorders. We used an MIA mouse model to investigate the postnatal epigenetic changes associated with exposure to the viral analogue PolyI:C. The effect of dietary supplement with omega-3 polyunsaturated fatty acids (PUFA) on exposed mice was also examined. Methylation was estimated genome-wide across gene regulatory regions. Widespread epigenetic changes were observed following exposure to inflammation during prenatal life. The differentially methylated gene set was enriched for genes involved in nervous system development and function. Omega-3 intervention modified the epigenetic profile, including a number of genes which were affected by MIA. These experiments indicate that environmental and genetic risk factors modulate similar biological pathways that are associated with neurodevelopmental disorders.
Project description:The hypothesis tested was that the uterine environment of lactating cows would affect conceptus gene expression. Approximately 65-75 days post-partum (dpp) the estrous cycles of non-lactating (dried off immediately post partum: n=12) and lactating (n=13) cows were synchronized and on Day 7 a high quality blastocyst derived from superovulated heifers was transferred. A control group of maiden heifers (n=8) were synchronized, inseminated to a standing heat and slaughtered on the same day as non-lactating and lactating recipients (Day 19; estrus=Day 0). The ipsilateral uterine horn was flushed with 10 ml PBS and the conceptus, when present, and uterine luminal fluid (ULF) snap frozen in liquid nitrogen prior to analysis. Gene expression analysis of the conceptus was performed by RNA sequencing analysis while amino acid (aa) composition of ULF was determined by High Performance Liquid Chromatography (HPLC). Eight differentially expressed genes (DEGs) were identified between conceptuses recovered from non-lactating cows versus heifers while 269 DEGs (100 up-regulated and 169 down-regulated) were identified between conceptuses recovered from lactating cows compared to heifers. The aa, alanine, glycine, serine and threonine, arginine, leucine and valine, were significantly lower in abundance in ULF recovered from heifers compared to both non-lactating or lactating cows. Glutamic acid, glutamine and lysine concentrations were lowest in heifers compared to both cow groups. This study demonstrates that exposure of a grade one embryo to a uterine environment that has been exposed to the metabolic stresses associated with lactation modifies the transcriptome of the conceptus and aa composition of the ULF.
Project description:The present studies tested the hypothesis that the elongating ovine conceptus and uterus produces EVs with the potential to mediate conceptus-maternal communication during early pregnancy. In Study One, EVs were purified from uterine luminal fluid (ULF) of day 14 cyclic sheep. The EVs were fluorescently labeled with PKH67 dye and infused into the uterine lumen of pregnant sheep for 6 days using an osmotic pump. On day 14, labeled EVs were observed in the conceptus trophectoderm and uterine epithelia, but not in the uterine stroma or myometrium. In Study Two, day 14 conceptuses were cultured ex vivo for 24 hours and found to release EVs into the culture medium. Isolated EVs from conceptuses were fluorescently labeled with PKH67 and infused into the uterine lumen of cyclic sheep for 6 days using an osmotic pump. On day 14, labeled EVs were observed in the uterine epithelia, but not in the uterine stroma or myometrium. No evidence of EV escape from the uterine lumen was observed by analysis of the ovary and other maternal tissues. Proteomics analysis of the day 14 conceptus-derived EVs identified 231 proteins that were enriched for extracellular space and several protein classes including proteases, protease inhibitors, chaperones and chaperonins. RNA-sequencing of day 14 conceptus-derived EVs detected expression of 512 mRNAs. The top expressed genes were overrepresented in ribosomal functions and components. These studies support the ideas that EVs emanate from both the conceptus trophectoderm and uterine epithelia and are involved in intercellular communication during the establishment of pregnancy. Transcriptional profiles from day 14 conceptus extracellular vesicles isolated from 24 hour conceptus-conditioned culture media (n=3) were generated by sequencing on the Illumina HiSeq 2500 platform.
Project description:The present studies tested the hypothesis that the elongating ovine conceptus and uterus produces EVs with the potential to mediate conceptus-maternal communication during early pregnancy. In Study One, EVs were purified from uterine luminal fluid (ULF) of day 14 cyclic sheep. The EVs were fluorescently labeled with PKH67 dye and infused into the uterine lumen of pregnant sheep for 6 days using an osmotic pump. On day 14, labeled EVs were observed in the conceptus trophectoderm and uterine epithelia, but not in the uterine stroma or myometrium. In Study Two, day 14 conceptuses were cultured ex vivo for 24 hours and found to release EVs into the culture medium. Isolated EVs from conceptuses were fluorescently labeled with PKH67 and infused into the uterine lumen of cyclic sheep for 6 days using an osmotic pump. On day 14, labeled EVs were observed in the uterine epithelia, but not in the uterine stroma or myometrium. No evidence of EV escape from the uterine lumen was observed by analysis of the ovary and other maternal tissues. Proteomics analysis of the day 14 conceptus-derived EVs identified 231 proteins that were enriched for extracellular space and several protein classes including proteases, protease inhibitors, chaperones and chaperonins. RNA-sequencing of day 14 conceptus-derived EVs detected expression of 512 mRNAs. The top expressed genes were overrepresented in ribosomal functions and components. These studies support the ideas that EVs emanate from both the conceptus trophectoderm and uterine epithelia and are involved in intercellular communication during the establishment of pregnancy.
Project description:Exposure of bovine conceptuses to colony stimulating factor 2 (CSF2) from Day 5 to 7 of development can increase the percent of transferred conceptuses that develop to term. The purpose of this experiment was to understand the mechanism by which CSF2 increases embryonic and fetal survival. Conceptuses were produced in vitro in the presence or absence of 10 ng/ml CSF2 from Day 5 to 7 after insemination, transferred into cows, and flushed from the uterus at Day 15 of pregnancy. There was a tendency (P=0.07) for the proportion of cows with a recovered conceptus to be greater for those receiving a CSF2 treated conceptus (35% for control vs. 66% for CSF2). Antiviral activity in uterine flushings, a measure of the amount of interferon-{tau} (IFNT2) secreted by the conceptus, tended to be greater for cows receiving CSF2-treated conceptuses than for cows receiving control conceptuses. This difference approached significance when only cows with detectable antiviral activity were considered (P=0.07). In addition, CSF2 increased mRNA for IFNT2 (P=0.06) and keratin 18 (P<0.05) in extraembryonic membranes. Among a subset of filamentous conceptuses that were analyzed by microarray hybridization, there was no effect of CSF2 on gene expression in the embryonic disc or extraembryonic membranes. Results suggest that the increase in calving rate caused by CSF2 treatment involves, in part, more extensive development of extraembryonic membranes and capacity of the conceptus to secrete IFNT2 at Day 15 of pregnancy.
Project description:Exposure of bovine conceptuses to colony stimulating factor 2 (CSF2) from Day 5 to 7 of development can increase the percent of transferred conceptuses that develop to term. The purpose of this experiment was to understand the mechanism by which CSF2 increases embryonic and fetal survival. Conceptuses were produced in vitro in the presence or absence of 10 ng/ml CSF2 from Day 5 to 7 after insemination, transferred into cows, and flushed from the uterus at Day 15 of pregnancy. There was a tendency (P=0.07) for the proportion of cows with a recovered conceptus to be greater for those receiving a CSF2 treated conceptus (35% for control vs. 66% for CSF2). Antiviral activity in uterine flushings, a measure of the amount of interferon-{tau} (IFNT2) secreted by the conceptus, tended to be greater for cows receiving CSF2-treated conceptuses than for cows receiving control conceptuses. This difference approached significance when only cows with detectable antiviral activity were considered (P=0.07). In addition, CSF2 increased mRNA for IFNT2 (P=0.06) and keratin 18 (P<0.05) in extraembryonic membranes. Among a subset of filamentous conceptuses that were analyzed by microarray hybridization, there was no effect of CSF2 on gene expression in the embryonic disc or extraembryonic membranes. Results suggest that the increase in calving rate caused by CSF2 treatment involves, in part, more extensive development of extraembryonic membranes and capacity of the conceptus to secrete IFNT2 at Day 15 of pregnancy. Experimental conditions: CSF2 treated vs. CSF2 nontreated bovine in vitro produced preimplantation embryos were tranfered to a receptor cow and recovered at Day 15 of embryo development. The embryonic disc (ED) and the trophectoderm (Tr) were used for the expression analysis separately. Biological replicates: CSF2 treated vs. nontreated bovine preimplantation embryos were used in a dye switch two-color microarray experimental design.
Project description:This study aimed to identify bovine conceptus-induced modifications to the endometrial transcriptome both dependent and independent of interferon tau (IFNT), dependent on conceptus origin [in vitro fertilization (IVF) or artifical insemination (AI) derived blastocysts] and dependent on conceptus sex. Major findings include identification of genes differentially expressed in endometrium in response to the conceptus but independent of IFNT and genes differentially expressed in endometrium in response to AI vs. IVF and male vs. female conceptuses.
Project description:Successful establishment and maintenance of pregnancy can be attained only through optimum conceptus-maternal cross talk. Despite significant progress in our understanding of the temporal changes in the transcriptome of the uterine endometrium, we have only a rudimentary knowledge of the genes and pathways governing growth and development of the bovine conceptus. In particular, very little information exists for the posthatchingembryo and elongating conceptus. This period of development is arguably the most important, as approximately 40% of all embryonic loss occurs between Days 8 and 17 of pregnancy in cattle. Here, we describe the global transcriptome profile of the bovine conceptus at five key stages of its pre- and peri-implantation growth (Days 7, 10, 13, 16, and 19) using state-of-the-art RNA sequencing techniques. More than 287 million reads were generated at the five stages, and more than 22?700 unique transcripts were detected. Analysis of variance followed by self-organizing maps identified differentially regulated (P < 0.05) genes organized in nine gene clusters forming a sequential transcript dynamics across these developmental stages. Of particular interest, genes in clusters 3 (n = 236) and 6 (n = 1409) were significantly up-regulated on Days 16 and 19, suggesting a role in maternal recognition and initiation of implantation. This transcriptome analysis of the bovine conceptus will provide a blueprint of the dynamic changes in gene expression occurring during maternal recognition and implantation and will complement existing knowledge of the temporal changes in the endometrial transcriptome, thus facilitating a better understanding of conceptus-maternal cross talk during the peri-implantation period of pregnancy. mRNA-seq study of bovine conceptuses at 5 stages of development (days 7, 10, 13, 16 and 19) post fertilization.