Consequences of conceptus exposure to colony stimulating factor 2 on survival, elongation, interferon-{tau} secretion and gene expression
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ABSTRACT: 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:The majority of pregnancy loss in cattle occurs between days 8 and 16 of gestation coincident with the initiation of conceptus elongation and the onset of maternal recognition of pregnancy. Differences in conceptus lengths on the same day of gestation may be related to an inherent lack of developmental competency or may simply be a consequence of asynchrony with the maternal environment. The primary objective of this work was to characterize differential patterns of mRNA expression between short and long bovine conceptuses recovered on Day 15 of gestation. Embryo selection is an important factor that contributes to pregnancy success following transfer of embryos produced in vivo or in vitro. Morphological evaluation of embryos for stage of development and quality grade is the most widely used method for predicting embryo viability in cattle. Multiple studies have demonstrated that there are significant differences in pregnancy rates across different morphological grades. However, morphological evaluation is not always the best predictor of pregnancy success. Therefore, it is of interest to develop an objective and highly predictive method of pre-transfer embryo screening. A secondary objective of this experiment was to characterize differential patterns of mRNA expression between Day 15 bovine conceptuses derived from Grade 1 (excellent) and Grade 3 (poor) embryos. In Experiment 1, gene expression was compared between Day 15 conceptuses derived from the transfer of Grade 1 (n=4) versus Grade 3 (n=3) embryos. In Experiment 2, gene expression was compared between Grade 1-derived Day 15 conceptuses classified as either short (n=5) or long (n=5) in length.
Project description:We aimed to study the effects of CSF2 treatment on the methylome of the Day 15 female and male embryo. Methylomic profiling of bovine extra-embryonic membrane at Day 15 post-insemination produced by IVF. Oocytes were matured and fertilized in vitro using a single Holstein bull. After 5 days in vitro culture, the embryos were either treated with 10 ng/ml bovine recombinant CSF2 or the Control (DPBS/BSA) until Day 7. At Day 7, the embryos were transferred into recipients. At day 15 following insemination, embryos were flushed and collected for total RNA and gDNA extraction. The gender of the embryos were determined by PCR prior to microarray analysis. CSF2 males were compared to Control males while CSF2 females were compared to Control females
Project description:RNA seq analysis was conducted to determine gene expression in the day 14 ovine conceptus. This was used in conjunction with the day 14 PPARG ChIP-seq analysis to identify genes bound by PPARG which were also expressed or not expressed in the day 14 conceptus. Understanding changes in gene expression during early pregnancy is critical to improving fertility and reproductive efficiency in ruminants. RNA seq analysis of 4 conceptuses from 4 individual Day 14 pregnant columbia/rambouillet crossbred ewes
Project description:We aimed to study the effects of CSF2 treatment on the transcriptome of the Day 15 female and male embryo. Within the raw files, channel 1= Cy3 and channel 2= Cy5 Transcriptional profiling of bovine extra-embryonic membrane at Day 15 post-insemination produced by IVF. Oocytes were matured and fertilized in vitro using a single Holstein bull. After 5 days in vitro culture, the embryos were either treated with 10 ng/ml bovine recombinant CSF2 or the Control (DPBS/BSA) until Day 7. At Day 7, the embryos were transferred into recipients. At day 15 following insemination, embryos were flushed and collected for total RNA and gDNA extraction. The gender of the embryos were determined by PCR prior to microarray analysis. CSF2 males were compared to Control males while CSF2 females were compared to Control females. Control females were also compared to control males.
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: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.
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:PPARG ChIP seq analysis was conducted to determine genes bound by and potentially regulated by PPARG in the developing ovine conceptus. Determination of gene regulation by prostaglandins through PPARG helps to improve our understanding of early pregnancy events and provides a basis for strategies to improve fertility and reproductive efficiency in ruminants. PPARG ChIP seq analysis of 4 conceptuses from 4 individual Day 14 pregnant columbia/ramboulette crossbred ewes
Project description:The objective of this study was to identify changes on the CSF2 embryo transcriptome that make them more able to become a blastocyst and more likely to survive after transfer. Embryos were treated with CSF2 at day 5 after fertilization and at day 6 morulae and blastocysts were select for the microarray analysis. A total of 160 genes that had a 1.5-fold difference in expression and a significance of P M-bM-^IM-$ 0.05 could be annotated. Analysis of the data identified 13 biological process ontologies that could be grouped into four functional groups (development and differentiation process, cell communication, apoptosis and cell adhesion). Experimental conditions: CSF2 treated vs. CSF2 nontreated bovine in vitro produced preimplantation embryos. Biological replicates: CSF2 treated vs. nontreated bovine preimplantation embryos were used in a dye switch two-color microarray experimental design. Ratio data was not used in these experiments.
Project description:We undertook gene expression microarray experiments to identify genes that are differentially expressed in different placental and fetal tissue, and resting and Pokeweed Mitogen (PWM) stimulated horse lymphocytes. Conceptus tissues were dissected to obtain chorionic girdle, chorion, and fetal tissue. Freshly isolated horse peripheral blood lymphocytes were split and harvested immediately, or stimulated with PWM and harvested over a five day period. These experiments utilized a custom Agilent horse array designed in house that featured >14,000 probes on an 8x15k array format. Several genes were selected from the results for validation by quantitative real-time PCR. QPCR results matched the microarray results very closely. Four Day 33-35 chorionic girdle RNAs were compared to matching chorion RNAs, and fetal tissue from two of the conceptuses. Gene expression in resting lymphocytes was compared to gene expression in PWM treated lymphocytes.