Project description:Co-ordinated regulation of endometrial gene expression is essential for successful pregnancy establishment. A non-receptive uterine environment may be a key contributor to pregnancy loss, as the majority of pregnancy losses occur prior to embryo implantation. DNA methylation has been highlighted as a potential contributor in regulating early pregnancy events in the uterus. It was hypothesized that DNA methylation regulates expression of key genes in the uterus during pregnancy. To gain support for this hypothesis the correlation between DNA methylation and gene expression was tested. Endometrial samples from fertile and sub-fertile dairy cow strains were obtained at day 17 of pregnancy or the reproductive cycle. Microarrays were used to characterize genome-wide DNA methylation profiles and data compared with transcription profiles which have been previously reported. 39% of DNA methylation probes assayed mapped to RefSeq genes with transcription measurements. The 1,000 most significant correlations were used for subsequent analysis. Of these, 52% percent were negatively correlated with gene expression. When this gene list was compared with previously reported gene expression studies on the same tissues, 42% were differentially expressed when comparing pregnant and cycling animals and 11% were differentially expressed comparing pregnant fertile and sub-fertile animals. DNA methylation status was correlated with gene expression in several pathways implicated in early pregnancy events. Although these data do not provide direct evidence of a causative association between DNA methylation and gene expression, this study provides critical support for an effect of DNA methylation in early pregnancy events and highlights candidate genes for future studies. The estrous cycles of 24 lactating dairy cows were synchronized (at 58.8 (SEM 3.77) and 60.2 (SEM 1.51) days post calving in dairy cows of sub-fertile and fertile strains, respectively) and 14 received a single embryo transferred on day 7 of the estrous cycle. Animals were slaughtered at day 17 of the reproductive cycle and endometrial tissues (both caruncular and intercaruncular) were sampled. Selection criteria for the study included strain and calving date, and health postcalving was an exclusion criterion (cows with severe uterine infections or mastitis were excluded before being enrolled in the embryo transfer round). Cows in each strain were matched for calving number and age. A total of 10 cycling and 12 pregnant animals enrolled in the study were utilized, due to the associated costs of slaughtering the cows. These animals represented fertile (six pregnant and five cycling Holstein-Friesian cows with New Zealand ancestry/M-bM-^IM-$30% North American genetics, n=11, NZ) and sub-fertile (six pregnant and five cycling Holstein-Friesian cows with >87% North American ancestry, n=11, NA) phenotypes of Holstein-Friesian dairy cows
Project description:OBJECTIVE: To reveal the miRNA expression profile of placental exosomes by high-throughput sequencing and screen key biomarkers in different pregnancy period to provide new research ideas for the establishment and maintenance of pregnancy in cows and other ruminants.It can also provide reference for other pregnancy diseases. METHOD: Exosmal miRNAs were isolated from non-pregnant cows(n=3,Gestation Day(G.D.) 0),early pregnant cows(n=3,G.D.60),Middile pregnant cows(n=3,G.D.150),Late pregnant cows(n=3,G.D.240), small RNA profiles were generated by deep sequencing, in triplicate, using Illumina Hiseq SE50. RESULTS: During pregnancy, there was a high quantity of placental exosomes in the peripheral blood of cows, which selectively loaded some miRNAs. The abundance and species of miRNAs various from different stages of pregnancy, suggesting that exosomal miRNAs is involved in the regulation mechanism of pregnancy.
Project description:Korean peninsular weather is rapidly becoming subtropical due to global warming. In summer 2018, South Korea experienced the highest temperatures since the meteorological observations recorded in 1907. Heat stress has a negative effect on Holstein cows, the most popular breed of dairy cattle in South Korea, which is susceptible to heat. To examine physiological changes in dairy cows under heat stress conditions, we analyzed the profiles circulating microRNAs isolated from whole blood samples collected under heat stress and non-heat stress conditions using small RNA sequencing. We compared the expression profiles in lactating cows under heat stress and non-heat stress conditions to understand the regulation of biological processes in heat-stressed cows. Moreover, we measured several heat stress indicators, such as rectal temperature, milk yield, average daily gain, and progesterone concentration. All these assessments showed that pregnant cows were more susceptible to heat stress than non-pregnant cows. Particularly, progesterone concentrations known to have maternal warming effects were at similar levels in non-pregnant cows but significantly increased in pregnant cows under heat stress conditions. The differentially expressed miRNAs and their putative target genes were analyzed in pregnant cows. Interestingly, we found that differentially expressed miRNAs (bta-miR-146b, bta-miR-20b, bta-miR-29d-3p, bta-miR-1246) specifically targeted progesterone biosynthesis (StAR) and the function of corpus luteum-related genes (CCL11, XCL), suggesting that pregnant cows with elevated progesterone concentrations are more susceptible to heat stress. In addition, we found the differential expression of 11 miRNAs (bta-miR-19a, bta-miR-19b, bta-miR-30a-5p, and several from the bta-miR-2284 family) in both pregnant and non-pregnant cows under heat stress conditions. In target gene prediction and gene set enrichment analysis, these miRNAs were found to be associated with the cytoskeleton, cell junction, vasculogenesis, cell proliferation, ATP synthesis, oxidative stress, and immune responses involved in heat response. These miRNAs can be used as potential biomarkers for heat stress.
Project description:This study was done to identify endometrial DNA methylation marks that can be associated with pregnancy outcomes in postpartum cows at the time of breeding. Results showed that postpartum cows that could become pregnant could be distinguishable based on their endometrial DNA methylation patterns at the time of breeding.
Project description:Pregnancy induces changes in the transcriptome of the bovine endometrium from 15 days after insemination. However, pregnancy is less likely to occur if cows had a postpartum bacterial infection of the uterus. We hypothesized that uterine bacterial infection alters the endometrial transcriptomic signature of pregnancy. To examine the endometrial transcriptomic signature of pregnancy, cows were inseminated 130 days after intrauterine infusion of pathogenic bacteria and endometrium was collected 16 days later for RNA sequencing. We found 171 pregnancy regulated genes in cows 146 days after bacterial infection. When comparing our findings with three previous studies that described the endometrial transcriptomic signature of pregnancy in healthy cows, 24 genes were consistently differentially expressed in pregnancy, including MX1, MX2 and STAT1. However, 12 pregnancy regulated genes were only found in the endometrium of healthy cows, including ISG15 and TRANK1. Furthermore, 28 pregnancy regulated genes were only found in the endometrium of cows following bacterial infection and these were associated with altered iNOS, TLR, and IL-7 canonical signaling pathways. Although 94 predicted upstream regulators were conserved amongst the studies, 14 were found only in the endometrium of pregnant healthy cows, and 5 were found only in cows following bacterial infection, including AIRE, NFKBIA, and DUSP1. In conclusion, there were both consistent and discordant features of the endometrial transcriptomic signature of pregnancy 146 days after intrauterine bacterial infusion. These findings imply that there is an essential transcriptomic signature of pregnancy, but that infection induces long term changes in the endometrium that affect the transcriptomic response to pregnancy.
Project description:We aim at identifying possible differences in miRNA profiles and individual circulating miRNA between healthy cows and cows with persistent inflammation as diagnosed by cytology and histology. Ultimately the miRNA profiles will be correslated with RNAseq results to be performed from endometrial biopsies (planned later on this year following laser micro dissection). Samples have been taken from 6 "healthy cows" with low presence of immune cells at 21 and 44 days post partum which were subsequently pregnant, and from 11 cows with high numbers of immune cells at 21 and 44 days post partum, all non pregnant.
Project description:Changes of Cytokines and chemokines profiles were sucessfully determined between mouse non-treated vs LPS treated pregnant uteri using Qiagen PCR array. Pregnant mouse (FVB strain E8.5-9.5) were treated with LPS(2.5ug/mouse) or saline as control. 8h- or 16-h later, uteri tissues (N=3) were collected.
Project description:Changes of Cytokines and chemokines profiles were sucessfully determined between mouse non-treated vs LPS treated pregnant uteri using Qiagen PCR array.
Project description:Purpose: characterize the uterine transcriptome profiles of pregnant (P) versus non-pregnant (NP) cows during early pregnancy and attempted to define a potential set of marker genes that can be valuable for predicting pregnancy outcome. Methods: beef cows were synchronized and artificially inseminated at detected estrus. Six days after AI, jugular blood samples and a biopsy from the uterine horn contralateral to the ovary containing the corpus luteum were collected. Based on pregnancy outcome on day 30, samples were retrospectively allocated to the following groups: Pregnant and Non-Pregnant. Both groups had similar plasma progesterone concentrations on D6. Uterine biopsies were submitted to RNA-Seq analysis in a Illumina HiScanSQ platform. Results: The 272,685,768 million filtered reads were mapped to the Bos taurus reference genome and 14,654 genes were analyzed for differential expression between groups. Transcriptome data showed that 216 genes are differently expressed when comparing NP versus P uterine tissue (Padj≤0.1). More specifically, 36 genes were up-regulated in P cows and 180 are up-regulated in NP cows. Conclusions: this study characterized a unique set of genes, expressed in the uterus on 6 days after insemination, that indicate a receptive state leading to pregnancy success. Furthermore, expression of such genes can be used as potential markers to efficiently predict pregnancy success. endometrial mRNA profiles of pregnant and non-pregnant cows were generated by deep sequencing using Illumina HiScanSQ platform BioProject PRJNA268916 SRA Study SRP05036
Project description:To get new insights into molecular mechanisms underlying the embryo-maternal communication during the pre-implantation period endometrium samples from Day 18 pregnant vs. non-pregnant twin cows were analyzed using a combination of subtracted cDNA libraries and cDNA array hybridization. Keywords: Comparison of endometrium of pregnant versus control animals