Project description:Primiparous sows were randomly allocated to two treatments and were separated from piglets 8h daily from Day 21 of lactation companied with daily boar exposure for oestrus detection until weaning (Day 28). Gene expression of Day 9 embryos were compared between control sows (FE; sows artificially inseminated when in heat during lactation ) and Skip-a-Heat sows (SE; sows in heat during lactation and artificially inseminated on the following oestrus cycle). Stimulating lactational oestrus then two mating strategies were applied to primiparous sows; 1)FE; sows were in heat during lactation and received artificial insemination) and Skip-a-Heat sows (SE; sows were in heat during lactation and received artificial insemination at fallowing oestrus cycle).
Project description:Sperm cells are characterized by a unique epigenome, and an incorrect establishment of DNA methylation patterns during the differentiation of male germ cells into spermatozoa has been associated with male infertility in several species. While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bovine sperm is still scarce. The purpose of this study is to compare the methylomes of sperm and somatic cell types in cattle using the RRBS technology.
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:Sperm cells are characterized by a unique epigenome, and an incorrect establishment of DNA methylation patterns during the differentiation of male germ cells into spermatozoa has been associated with male infertility in several species. While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bovine sperm is still scarce. The purpose of this study is to compare the methylomes of sperm and somatic cell types in cattle using the MeDIP-chip technology (methylated DNA immunoprecipitation followed by microarray hybridation).
Project description:Artificial insemination (AI) is the preferred method for reproduction in the majority of the intensive pig production systems Worldwide. To this end, fresh extended ready-to-use semen doses are either purchased from AI-centres or produced by boars kept on-farm. For profitable semen production, it is necessary to obtain a maximum amount of high quality semen from each boar. This paper reviews current knowledge on factors that may affect semen quality by influencing the boar or the semen during processing. Genetic markers could be used for early detection of boars with the highest fertility potential. Genetic selection for fast growth might jeopardize semen quality. Early detection of boars no longer fit for semen production might be possible by ultrasonography of the testes. Seasonal variation in sperm quality could be associated with changes in photoperiod and heat stress during summer. Comfortable housing, with appropiate bedding material to avoid locomotion problems is essential. In some areas, cooling systems may be necessary to avoid heat stress. The sperm quality can be manipulated by feeding strategies aiming, for instance, to increase sperm resistance to oxidative stress and extend storage duration. High collection frequency will negatively influence sperm quality. Also, if collection is not hygienically performed it will result in bacterial contamination of the semen doses. The concern over bacterial contamination has risen not only because of its negative effect on semen quality but also due to the detection of antimicrobial resistance in isolates from extended semen. Moreover, bacterial and viral pathogens must be monitored because they affect semen production and quality and constitute a risk of herd infection. During processing, boar sperm are submitted to many stress factors that can cause oxidative stress and capacitation-like changes potentially reducing their fertility potential. Dilution rate or dilution temperature affects the quality of the semen doses. Some packaging might preserve semen better than others and some plastic components might be toxic for sperm. Standard operation procedures and quality assurance systems in AI centres are needed.
Project description:Since CNVs play a vital role in genomic studies, it is an imperative need to develop a comprehensive, more accurate and higher resolution porcine CNV map with practical significance in follow-up CNV functional analyses To detect CNV of pigs, we performed high density aCGH data of diverse pig breeds in the framework of the pig draft genome sequence (Sscrofa10.2) 9 Chinese indigenous pig, one Chinese wild boar and 2 commercial pigs were detected using one pig of Duroc as reference. These 12 animals include 1 wild pig, 2 pigs each from Yorkshire and Landrace as the representatives of modern commercial breeds and 9 unrelated individuals selected from 6 Chinese indigenous breeds (2- Tibetan pig, 2- Diannan small-ear pig, 2-Meishan pig, 1- Min pig, 1-Daweizi pig, and 1-Rongchang pig).
Project description:Artificial insemination in small ruminants is most commonly performed using fresh semen due to the low fertility rates typically achieved with frozen spermatozoa. Usually, when developing and applying assisted reproductive technologies, sheep and goats are often lumped together as one specie. In order to optimize sperm cryopreservation protocols in sheep and goat, differences in sperm proteomics between ram and buck are necessary to detect, which may contribute to differences in sperm function and fertility.