Expression data from porcine ovary tissue of sows from two prolificacy levels
Ontology highlight
ABSTRACT: Previous results from a genome scan in a F2 Iberian by Meishan intercross showed several chromosome regions associated with litter size traits. In order to identify candidate genes underlying these QTL we have performed an ovary gene expression analysis during pregnancy. F2 sows were ranked by their estimated breeding values for prolificacy, the six sows with higher EBV (HIGH prolificacy) and the six with lower EBV (LOW prolificacy) were selected. Samples were hybridized to Affymetrix porcine expression microarrays. The statistical analysis with a mixed-model approach identified 221 differentially expressed probes, representing 189 genes. These genes were functionally annotated in order to identify the genetic pathways overrepresented. Among the most represented functional groups the first one was immune system response activation against external stimulus. The second group was made up of genes which regulate the maternal homeostasis by complement and coagulation cascades. The last group was involved on lipid and fatty acid enzymes of metabolic processes, which participate in steroidogenesis pathway. In order to identify powerful candidate genes for prolificacy, the second approach of this study was merging microarray data with position information of QTL affecting litter size, previously detected in the same experimental cross. According to this, we have identified 27 differentially expressed genes co-localized with QTL for litter size traits, which fulfill the biological, positional and functional criteria. Twelve ovary samples: six high prolific sows and low prolific sows, slaughtered after 30 days of pregnancy. Each sample is the average between right and left ovary from each sow.
Project description:Previous results from a genome scan in a F2 Iberian by Meishan intercross showed several chromosome regions associated with litter size traits. In order to identify candidate genes underlying these QTL we have performed an ovary gene expression analysis during pregnancy. F2 sows were ranked by their estimated breeding values for prolificacy, the six sows with higher EBV (HIGH prolificacy) and the six with lower EBV (LOW prolificacy) were selected. Samples were hybridized to Affymetrix porcine expression microarrays. The statistical analysis with a mixed-model approach identified 221 differentially expressed probes, representing 189 genes. These genes were functionally annotated in order to identify the genetic pathways overrepresented. Among the most represented functional groups the first one was immune system response activation against external stimulus. The second group was made up of genes which regulate the maternal homeostasis by complement and coagulation cascades. The last group was involved on lipid and fatty acid enzymes of metabolic processes, which participate in steroidogenesis pathway. In order to identify powerful candidate genes for prolificacy, the second approach of this study was merging microarray data with position information of QTL affecting litter size, previously detected in the same experimental cross. According to this, we have identified 27 differentially expressed genes co-localized with QTL for litter size traits, which fulfill the biological, positional and functional criteria.
Project description:The seminal plasma (SP) is the liquid component of semen that facilitates sperm transport through the female genital tract. SP modulates the activity of the ovary, oviductal environment and uterine function during the periovulatory and early pregnancy period. Extracellular vesicles (EVs) secreted in the oviduct (oEVs) and uterus (uEVs) have been shown to influence the expression of endometrial genes that regulate fertilization and early embryo development. In some species, semen is composed of well-separated fractions that vary in concentration of spermatozoa and SP composition and volume. This study aimed to investigate the impact of different accumulative fractions of the porcine ejaculate (F1, composed of the sperm-rich fraction (SRF); F2, composed of F1 plus the intermediate fraction; F3, composed of F2 plus the post-SRF) on oEVs and uEVs protein cargo. Six days after the onset of estrus, we determined the oEVs and uEVs size and protein concentration in pregnant sows by artificial insemination (AI-sows) and in non-inseminated sows as control (C-sows). We also identified the main proteins in oEVs and uEVs, in AI-F1, AI-F2, AI-F3, and C-sows. Our results indicated that although the size of EVs is similar between AI- and C-sows, the protein concentration of both oEVs and uEVs was significantly lower in AI-sows (p < 0.05). Proteomic analysis identified 38 unique proteins in oEVs from AI-sows, mainly involved in protein stabilization, glycolytic and carbohydrate processes. The uEVs from AI-sows showed the presence of 43 unique proteins, including already-known fertility-related proteins (EZR, HSPAA901, PDS). We also demonstrated that the protein composition of oEVs and uEVs differed depending on the seminal fraction(s) inseminated (F1, F2, or F3). In conclusion, we have found a specific protein cargo in uterine and oviductal EVs depending on the type of semen fraction the sow was inseminated with, and these insemination with different seminal fractions results in the oviductal and uterine secretion of specific EVs proteins are closely associated with reproductive processes.
Project description:Embryonic survival rate is an important factor for the fecundity of sows, and it is affected by endometrium secreting histotroph. A higher concentration of calcium ion has been observed in the uterus of the high prolific Erhualian sows (EH) compared with low prolific ones (EL), which suggests EH sows had a greater establishment and maintenance of pregnancy, and thus increase embryonic survival rate during peri-implantation period. In order to understand the mechanisms of endometrium secreting histotroph affecting embryonic survival rate during Erhualian peri-implantation period, the expression patterns of endometrial mRNA in the EH and EL on day 12 of gestation were analyzed using RNA sequencing technology. 164 differentially expressed genes (DEGs) were identified (Padj < 0.05, |log2(FC)| ≥ 1),including 46 upregulated and 118 downregulated genes in the EH group compared with EL group. Among these DEGs, 17 DEGs have been previously reported as DEGs in other pig breeds for litter size. Gene Ontology (GO) enrichment indicated that a subset of DEGs were involved in the calcium ion binding and cell adhesion. Solute carrier family 8 member A3 (SLC8A3) and solute carrier family 24 member 4 (SLC24A4) were upregulated genes (Padj < 0.05) in EH group and they were considered as key candidate genes expressed in endometrium to affect embryonic survival rate during peri-implantation period. The present results will aid in understanding the variation of litter size in Erhualian breed during peri-implantation period.
Project description:Prolificacy related traits are of great economical interest in the pig industry. microRNAs (miRNAs) are post-transcriptional regulators of gene expression important for reproductive processes. In pigs, the roles of ovarian miRNAs during gestation remain unknown although the ovaries are essential during gestation. It has been hypothesised that ovarian miRNAs could participate during the porcine gestation and, moreover, they could influence the prolificacy levels of sows. The miRNA expression profile was compared in the ovaries of pregnant Iberian x Meishan F2 sows displaying extreme phenotypes regarding prolificacy levels defined as the number of embryos (NE) attached to the uterus at 30-32 days of gestation. miR-146a-5p and miR-142-3p were differentially expressed between high (NEM-bM-^IM-%13) and low (NEM-bM-^IM-$11) prolificacy sows. In silico functional analyses of the predicted mRNA targets for these miRNAs revealed that miR-146a-5p targets were mainly involved in the immune system response important for the establishment of the maternal-foetal tolerance, implantation and maintenance of pregnancy. On the other hand, miR-142-3p targets participated in different biological processes that would contribute to the homeostasis maintenance to ensure a correct functional development of the ovaries. miRNAs associated with prolificacy levels could regulate negatively, by a novel post-transcriptional mechanism, their predicted mRNA targets, PPM1K, TLR1 and CPEB2 which have been reported as differentially expressed in the ovaries of pregnant sows regarding the prolificacy levels. Furthermore, among predicted mRNA targets for miRNAs associated with prolificacy, four genes, differentially expressed in the ovaries of pregnant sows regarding prolificacy levels, (LRRK1, BAT1, CPEB2, CCL8) are proposed to be good candidate genes for litter size due to their location within confidence intervals for prolificacy QTL described previously. Overall, it is suggested that the up-regulation of miR-146a-5p and miR-142-3p in the ovaries of pregnant sows could help in the establishment of a uterine environment, which would favor the embryonic development. Total RNA was isolated from uterus of Iberian x Meishan F2 pregnant sows divided into two groups: High prolificacy sows (n=3) and Low prolificacy sows (n=3). RNA was labeled with the Cy3-like Hy3M-bM-^DM-" dye, mixed with a pool of RNA from the six samples labeled with the Cy5-like Hy5M-bM-^DM-" dye, and hybridized to two-color miRCURYM-bM-^DM-" arrays from ExiqonM-BM-..
Project description:Prolificacy related traits are of great economical interest in the pig industry. microRNAs (miRNAs) are post-transcriptional regulators of gene expression important for reproductive processes. In pigs, the roles of ovarian miRNAs during gestation remain unknown although the ovaries are essential during gestation. It has been hypothesised that ovarian miRNAs could participate during the porcine gestation and, moreover, they could influence the prolificacy levels of sows. The miRNA expression profile was compared in the ovaries of pregnant Iberian x Meishan F2 sows displaying extreme phenotypes regarding prolificacy levels defined as the number of embryos (NE) attached to the uterus at 30-32 days of gestation. miR-146a-5p and miR-142-3p were differentially expressed between high (NE≥13) and low (NE≤11) prolificacy sows. In silico functional analyses of the predicted mRNA targets for these miRNAs revealed that miR-146a-5p targets were mainly involved in the immune system response important for the establishment of the maternal-foetal tolerance, implantation and maintenance of pregnancy. On the other hand, miR-142-3p targets participated in different biological processes that would contribute to the homeostasis maintenance to ensure a correct functional development of the ovaries. miRNAs associated with prolificacy levels could regulate negatively, by a novel post-transcriptional mechanism, their predicted mRNA targets, PPM1K, TLR1 and CPEB2 which have been reported as differentially expressed in the ovaries of pregnant sows regarding the prolificacy levels. Furthermore, among predicted mRNA targets for miRNAs associated with prolificacy, four genes, differentially expressed in the ovaries of pregnant sows regarding prolificacy levels, (LRRK1, BAT1, CPEB2, CCL8) are proposed to be good candidate genes for litter size due to their location within confidence intervals for prolificacy QTL described previously. Overall, it is suggested that the up-regulation of miR-146a-5p and miR-142-3p in the ovaries of pregnant sows could help in the establishment of a uterine environment, which would favor the embryonic development.
Project description:In our previous sow study, two subpopulations of feed-restricted sows (60% of anticipated feed intake) were identified: ‘Restrict (Risk)’ that mobilized higher levels of body tissue stores (>40MJ ME day-1) compared to ‘Restrict (Non-Risk)’ sows (Patterson et al. Reprod. Fert. Deveopl., 2011, 23, 889-898) and although Risk sows maintain higher litter growth in the weaned litter, this was at the expense of lower embryonic weight in their subsequent litter compared with Non-Risk sows. To understand the underlying molecular mechanisms involved, we investigated the gene expression profiles of embryos from Risk and Non-Risk litters in this experiment.
Project description:This study provide an opportunity to elucidate the genetic control of fetal implantation and improve our understanding of fetal implantation and gestation maintenance, thus make further improvement for litter size of pigs. Nine pregnant sows were slaughtered by electrical on day 13, day 18 and day 24 after insemination (the pregnant group, three sows every period). The non-pregnant sows were slaughtered on day 13 after inseminated (n=3).In pregnant sows, samples of the endometrium attachment sites and inter-sites were taken. Samples from the endometrium of the non-pregnant sows were taken from comparable locations.
Project description:The objective of modern pig breeding is to exhaust the genetic potential in reproduction performance of sows regarding to litter size and litter weight of piglets. During gestation period, umbilical cord contributes to placenta-fetal communication and plays an indispensable role in the intrauterine embryonic development. In this study, we attempted to analyze the molecular mechanism of reproductive declined in high-parity sows from the perspective of umbilical cord blood. Firstly, we analyzed the reproductive character data of sows, and then the histological analysis of umbilical cord phenotype was performed. Next, we evaluated the effect of umbilical cord blood exosomes (UCB-EXO) on angiogenesis. Moreover, the expression characteristics of miRNA in UCB-EXO of high-parity sows with poor reproductive performance (OS) and multiparous sows with excellent reproductive performance (MS) were analyzed. Results showed that the reproductive performance performed best at 3rd-7th and gradually decreased after 8th parities. Angiogenesis was repressed in OS piglets. Moreover, the Exo-MS exhibited pro-angiogenesis properties, with those of Exo-OS were diminished. With the increase of parities, the angiogenesis and immune function of sows decreased significantly, greatly limited the reproductive potential of sows. The data demonstrated that miRNAs of UCB-EXO played a central role in intrauterine development and suggested a novel possible explanation for reproductive potential, provides reference for increasing female reproductive efficiency.
Project description:The Chinese Erhualian is one of the most prolific pig breeds in the world, which farrows at least five more piglets per litter than Western pig breeds partly due to a greater ovulation rate. Differences in the transcriptome of Chinese Erhualian and Large White ovaries directly result in variation of ovulation rate. To understand the molecular basis related to ovulation rate in Chinese indigenous and Western breeds, samples were collected and used to hybridized. This study reveals many potential avenues of investigation for seeking new insights into ovarian physiology and the genetic control of reproduction. Expression profiling experiments were conducted to identify differentially expressed genes in ovarian follicles at the preovulatory stage of a PMSG-hCG stimulated estrous cycle from 3 Chinese Erhualian and 3 Large White cycling sows by using the Affymetrix Porcine Genechip™.
Project description:An F2 cross between two highly divergent porcine breeds for most productive traits, including prolificacy, was generated. F2 sows were classified as of high or low prolificacy based on phenotypic records of four consecutive parities (total number of piglets born and number of piglets born alive were recorded). At the fifth gestation, sows were slaughtered at day 30-32 of gestation, and the number of corpora lutea and number of embryos were registered. Samples from different tissues were snap frozen in liquid nitrogen for further studies. Uterus samples were used for total RNA extraction and hybridized on the affymetrix porcine genechip for comparison between high and low prolificacy F2 sows.