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: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.
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: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:To further knowledge of piglet maturity, we have developed a microarray analysis to describe biological processes and to find candidate genes for key roles in piglet maturity. The objective was to identify which genes and biological processes are specifically involved in the difference between two extreme breeds: Large White (LW) and Meishan (MS). The LW breed is a selected breed known to show an increased rate of mortality at birth, while the MS breed presents more robust piglets at birth. MS and LW sows were inseminated with mixed semen (LW and MS) hence each litter was composed of pure fetuses (LW or MS) and crossed fetuses (LWMS from MS sows and MSLW from LW sows). To assay for changes in gene expression during piglet maturity, mRNA was isolated from 61 fetal skeletal muscle samples with 8 different conditions: two fetal gestational ages (90 or 110 days of gestation), associated with four genotypes (two extreme breeds for mortality at birth (MS and LW) and two crossed breeds (MSLW and LWMS)). MS fetuses are known to have a better survival at birth than LW fetuses. An understanding of maturity is possible with the comparison between the fetal gestational ages and between the two extreme breeds. The impact of parental genotypes is studied with the presence of crossed fetuses. After quality control and normalization, only 61 samples were conserved (represented here).
Project description:Transcriptional profiling of Day 30 embryos (D30E) was performed. First parity sows were submitted to an ovulation-induction protocol, intermittent suckling (IS), during lactation. IS consisted of 8 h/d separation from their litters during the last 7d of a 28d lactation. During separation, sows received boar exposure. There were 3 treatments: control (C28, n=19), where piglets were weaned at D28 of lactation and were bred after weaning and two IS treatments: sows were either bred at their first induced estrus during lactation (IS21FE, n=18), or were “skipped” and bred at their second estrus (IS21SE, n= 17) which occurred after final weaning at D28. Sows were slaughtered and embryos were collected on D30 of gestation for DNA PCR sexing. Later, D30E from the same sex with similar weight were pooled for further microarray investigation.
Project description:To further knowledge of piglet maturity, we have developed a microarray analysis to describe biological processes and to find candidate genes for key roles in piglet maturity. The objective was to identify which genes and biological processes are specifically involved in the difference between two extreme breeds: Large White (LW) and Meishan (MS). The LW breed is a selected breed known to show an increased rate of mortality at birth, while the MS breed presents more robust piglets at birth. MS and LW sows were inseminated with mixed semen (LW and MS) hence each litter was composed of pure fetuses (LW or MS) and crossed fetuses (LWMS from MS sows and MSLW from LW sows).