Maternal recognition of pregnancy in the horse: are microRNAs the secret messengers? [miRNA-seq]
Ontology highlight
ABSTRACT: The signal for maternal recognition of pregnancy (MRP) has still not been identified in the horse. Endometrial biopsies, uterine fluid, embryonic tissues and yolk sac fluid were collected 13 days after ovulation during pregnant and control cycles from the same mares. Micro-RNA-Sequencing was performed on all collected samples and mRNA-Sequencing was conducted on the same endometrial and embryonic tissue samples
Project description:The signal for maternal recognition of pregnancy (MRP) has still not been identified in the horse. Endometrial biopsies, uterine fluid, embryonic tissues and yolk sac fluid were collected 13 days after ovulation during pregnant and control cycles from the same mares. Micro-RNA-Sequencing was performed on all collected samples and mRNA-Sequencing was conducted on the same endometrial and embryonic tissue samples
Project description:mRNA profiles of (1) equine endometrium collected 14, 22, and 28 days after ovulation from pregnant mares and (2) equine endometrium collected 20 days after ovulation from pregnant mares, and from non-pregnant mares which displayed and failed to display extended luteal function following the administration of oxytocin.
Project description:At ovulation detection (D0), oral treatment with urea was initiated and continued until D7. Mares received a treatment or control diet (n= 11 mares/group) in a crossover design. The treated group received urea (0.4 g/kg body weight) mixed with sweet feed and molasses, the control group received sweet feed and molasses alone. Blood samples were collected daily, one hour after feeding, for BUN determination. Uterine and vaginal pH were evaluated with an epoxy pH probe. Endometrial biopsies were taken transcervically one hour after the last feeding on D7. RNA sequencing of the endometrium of a subset of mares (n=6/group) was conducted.
Project description:While the equine oviduct clearly affects early embryo development and while the selective transport of equine embryos through the oviduct indicates a reciprocal interaction, the influence of the embryo on gene expression in the oviduct remains to be determined in the horse. The aim of this study was to examine this by means of RNA sequencing. Four days after ovulation, the oviduct epithelial cells ipsilateral and contralateral to the ovulation side from five cyclic and five pregnant mares were collected. mRNA was extracted and samples were sequenced using the Illumina Hiseq-2000 sequencer. Data analysis was performed with the CLC Genomics software and differentially expressed genes (DEGs) were determined (p-value ≤ 0.05 and absolute fold change ≥ 2). ClueGO was used for functional interpretation. A total of 26,991 genes was identified and 253 genes were found to be upregulated and 108 to be downregulated in the pregnant ipsilateral oviduct, when compared to the cyclic ipsilateral oviduct. Comparison of the ipsilateral and the contralateral oviduct indicated 164 DEGs in pregnant mares and 77 DEGs in cyclic mares. Functional enrichment analysis only detected differences in the comparison of pregnant and cyclic ipsilateral oviducts and showed that the equine embryo affects the expression of immune response related genes in the oviduct, with marked upregulation of interferon associated genes. This research represents the foundation for further assessment of the role of specific genes in the early embryo-maternal dialogue of the horse.
Project description:We developed an experimental model to elevate BUN during diestrus. There were both urea and control treatments (7 mares/treatment), done in a crossover design. Urea treatment consisted of a loading dose of urea (0.03 g/kg of urea) and urea injections over 6 hours (0.03 g/kg/hr). Control mares received the same volume of saline solution. Blood samples were collected to measure BUN. Uterine and vaginal pH were evaluated after the last intravenous infusion, then endometrial biopsies were collected for RNA-sequencing
Project description:Embryo implantation in the mare occurs just over one month after fertilization, coinciding with the production of chorionic gonadotropin. The factors that regulate this late implantation in the mare, and whether they are unique or shared with more invasive embryos, remains poorly understood. This study aimed to determine and compare the transcriptome and subpopulations of endometrial cells before and after embryo implantation in the horse. Single-cell RNA sequencing was used to characterize the transcriptome of nearly 97 000 endometrial cells collected from biopsies of the endometrium at the beginning (day 33 of gestation) and the end of the embryo implantation (day 42 of gestation) in mares. Sixteen immune and 24 non-immune cell clusters were identified representing all known main cell populations, as well as subpopulations of horse immune cells such as resident innate lymphoid cells and mucosal-associated invariant T cells. Contrary to current knowledge, endometrial natural killer (eNK) cells were the most abundant endometrial leukocyte population during implantation in horses. Moreover, eNK cells not only expressed genes which may interact with fetal MHC I such as LY49F but also exert immunoregulatory functions regardless of MHC I expression such as CD96/TIGIT. Analogous to other species studied, upregulation of CXCR4 was found in several subpopulations of immune cells. Our results suggest that despite distinctive and later placentation compared with humans, horses share some key similarities in the mechanisms of embryo implantation.
Project description:The aim of the study was to compare the effects of maternal age on embryos in horses. For that, 11 embryos were collected at 8 days post ovulation (expanded blastocyst stage) from 2 groups of multiparous mares of different age: 5 from young mares (<10 years old) and 6 from old mares (10-17 years old). Embryos collected were cut in 2 parts: one hemi-embryo containing pure trophoblast and the other one containing trophoblast + inner cell mass. ARN extractions were performed for all samples using PicoPure RNA isolation kit (Applied Biosystem). Five nanograms of both parts of each embryo were sequenced in paired-end with a length of 30-50bp separately using Illumina NextSeq 500 High. Data were trimmed using Cutadapt. Sequences with less than 10bp were removed.
Project description:The aim of the global study was to compare the effects of maternal age and parity on gene expression of equine embryos. For that, 17 embryos were collected at 8 days post ovulation (expanded blastocyst stage) from 3 groups of young or old nulliparous or multiparous mares: 6 from young nulliparous mares (5 or 6 year-old, never foaled before), 5 from young multiparous mares (6 year-old and foaled at least once) and 6 from old multiparous (10-16 year-old and foaled at least once). Embryos collected were cut in 2 parts: one hemi-embryo containing pure trophoblast and the other one containing trophoblast + inner cell mass. ARN extractions were performed for all samples using PicoPure RNA isolation kit (Applied Biosystem). Five nanograms of both parts of each embryo were sequenced in paired-end with a length of 30-50bp separately using Illumina NextSeq 500 High. Data were trimmed using Cutadapt. Sequences with less than 10bp were removed. Data for young and old multiparous mares had been already published in [accession: GSE162893; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE162893]. Only data for embryos collected from young nulliparous mares are deposited here
Project description:We undertook gene expression microarray experiments to identify genes that are differentially expressed in invasive (Chorionic Girdle) and non-invasive (Chorion) placental tissue, and resting and Pokeweed Mitogen (PWM) stimulated horse lymphocytes. Conceptus tissues were dissected to obtain chorionic girdle, and chorion. 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 commercially available Agilent horse array that featured >43,000 probes on a 4x44k array format.
Project description:ChRO-seq provides quantative information about gene expression levels in liver tissue taken at necropsy from two healthy Quarter Horse mares.