Journal of reproduction and fertility. Supplement最新文献

{"title":"Uterine function in Meishan pigs.","authors":"R. Christenson, J. Vallet, K. Leymaster, L. D. Young","doi":"10.1530/biosciprocs.14.0020","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.0020","url":null,"abstract":"The Meishan pig provides a biological model with the genetic capacity to express a high prolificacy. This prolificacy can be partially attributed to a higher ovulation rate and a higher rate of prenatal survival at a given ovulation rate throughout gestation than in European breeds. Both early embryonic survival (factors inherent to the ovum and uterus, which occur before day 25 of gestation) and uterine capacity (factors inherent to uterine limitation, which occur from 30 days of gestation to parturition) may contribute to prenatal survival. Crossbreeding studies show that the prolificacy of Meishan pigs is primarily of maternal origin, but not whether the effects occur via the ovum, uterus or systemic factors. Although there have been few comparative studies on uterine function for prolific pigs, experiments relating to three general areas have been reported. During neonatal uterine development, endometrial gland development occurs shortly after birth in Meishan and European breeds. Tissue culture for 24 h showed that secretion of at least three uterine proteins (one identified as retinol-binding protein) increased in clear temporal association with development of the endometrial gland. The secretion of two additional proteins appears to change in a breed-specific manner. Although regulatory roles for uterine proteins remain to be defined, biochemical events associated with neonatal endometrial gland development may affect subsequent adult uterine function. During the time of maternal recognition of pregnancy or early gestation, reports suggest that uterine secretions are enhanced in Meishan pigs, which may partially explain their increased prolificacy. However, other studies show smaller embryo and placental weights at day 30 of gestation, suggesting that prolificacy of Meishan females is related to a maternal ability to control embryo/fetal and placental growth. During the later fetal period (uterine capacity) in European pigs, endometrial response to a crowded uterine environment is minimal, but the conceptus responds to a crowded uterine environment by altering placental function; similar experiments using Meishan pigs are in progress. Once the regulatory determinants of uterine function are understood, improvements can possibly be made in the reproductive efficiency of all swine.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"9 1","pages":"279-89"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87688530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing management of natural and artificial matings in swine.","authors":"W. Flowers, K. Esbenshade","doi":"10.1530/biosciprocs.14.0015","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.0015","url":null,"abstract":"A successful mating involves the coordination of many physiological events including insemination, gamete transport and ovulation. As more basic information about these processes becomes available, it is apparent that there are opportunities for manipulating these physiological events and enhancing the reproductive success of natural and artificial matings. The primary intent of this review is to examine the effectiveness of several of these strategies, as determined by their influence on farrowing rate and litter size. It is evident that the timing, duration and pattern of ovulation in pigs are extremely variable. Thus, increasing the frequency and changing the timing of matings during oestrus has received renewed interest. In general, if a female exhibits oestrus for more than 1 day, then increasing the frequency of matings has a greater influence on reproductive performance than does altering the timing of matings. In addition, litter size is more responsive to increased mating frequencies than is farrowing rate. Increasing the number of matings per oestrus via the use of combinations of natural service and artificial insemination, compared with the use of either alone, appears to enhance reproductive performance. It has been well documented that several aspects of the mating process itself can advance the onset of ovulation and enhance sperm transport and storage in the female reproductive tract. As a result, the use of these stimuli in conjunction with natural and artificial matings provide opportunities for enhancing fecundity. Pre- and post-breeding treatments with vasectomized boars, nonviable semen, oestrogens and seminal plasma have all been reported to increase farrowing rate and litter size. With artificial insemination, additions of prostaglandins, oxytocin, oestrogens and leucocytes to semen have been reported to enhance reproductive performance, albeit with varying degrees of success. Personnel and boar needs are important components in optimizing breeding management. Estimates of these needs for artificial and natural matings are discussed.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"73 1","pages":"217-28"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90756113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effectiveness of in vitro maturation and in vitro fertilization techniques in pigs.","authors":"K. Niwa","doi":"10.1530/biosciprocs.14.004","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.004","url":null,"abstract":"In vitro maturation and in vitro fertilization techniques in pigs have progressed considerably in recent years. Many reports focus on the factors affecting in vitro maturation that lead to normal male pronuclear formation or monospermy after fertilization in vitro. It is suggested that pig follicular fluid (pFF), follicle somatic cells and various hormones are important factors for the maintenance of cytoplasmic maturation of oocytes in vitro, but that fetal calf serum (FCS), which is generally added to maturation medium, is detrimental. A series of experiments clearly indicate that the glutathione (GSH) content of matured oocytes increases greatly when maturation medium is supplemented with cysteine, a precursor of GSH, and the rates of male pronuclear formation increase in parallel with the increasing GSH content. To prevent polyspermy, conditions of maturation and of fertilization in vitro are important. Culture of oocytes in medium with FCS for the first 24 h and with BSA for the second 24 h decreases the incidence of polyspermy, without a significant effect on nuclear maturation. However, it has been shown that secretory macromolecules of the oviduct may reduce the incidence of polyspermy by interacting with fertilizing spermatozoa rather than with oocytes. A reduction of polyspermy by treating spermatozoa with pFF is also reported. In addition to the many improvements in the methodology of in vitro fertilization using unfrozen spermatozoa in pigs, techniques for fertilizing oocytes in vitro with frozen epididymal and ejaculated spermatozoa have also recently been developed.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"1 1","pages":"49-59"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90398542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Early embryonic development in prolific Meishan pigs.","authors":"S. Ford, C. Youngs","doi":"10.1530/biosciprocs.14.0019","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.0019","url":null,"abstract":"Prenatal mortality in European pigs is estimated at 30-40%, the majority of which occurs between days 12 and 18 after mating. Chinese Meishan pigs are prolific, averaging three to five more pigs per litter than do European breeds. Early reports into the fecundity of Meishan females suggested that their prolificacy resulted from lower embryonic mortality when compared with European females exhibiting the same ovulation rate. The preponderance of evidence suggests that there are no differences between Meishan and European breeds in either morphological embryo diversity within a litter or embryo mortality before day 12 after mating. Recent studies from our laboratory suggest that preimplantation embryos from Meishan females exhibit markedly reduced growth rates and oestrogen secretory activities through day 12 when compared with embryos from Yorkshire females. The significantly reduced conceptus sizes of Meishan versus European breeds on day 30 of gestation provide additional evidence of the reduced growth rate of Meishan embryos. Furthermore, because embryonic oestrogen production is known to alter uterine secretion of histotroph, the lower oestrogen production by Meishan embryos in the Meishan uterus may result in more gradual alterations in the uterine environment that are beneficial for conceptus survival and subsequent litter size. Recent studies using cross-transfer of Meishan and Yorkshire embryos on day 2 after mating have led to the suggestion that there is a major effect of recipient genotype on embryonic growth rate and oestrogen secretion. In these studies, both Meishan and Yorkshire embryos transferred to Meishan uteri exhibited marked decreases in morphological development and oestrogen content on day 12 when compared with embryos transferred to Yorkshire recipients. These data suggest the presence of factor(s) in endometrial secretions from Meishan females that reduce the growth rate and oestrogen secretory potential of preimplantation conceptuses.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"164 1","pages":"271-8"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90221518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of insulin-like growth factors and epidermal growth factor-related peptides in intraovarian regulation in the pig ovary.","authors":"J. Hammond, S. Samaras, R. Grimes, J. Leighton, J. Barber, S. Canning, H. Guthrie","doi":"10.1530/biosciprocs.14.008","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.008","url":null,"abstract":"The autocrine and paracrine role of the insulin-like growth factors (IGFs) and epidermal growth factor (EGF)-related peptides in pig ovary are reviewed. For convenience, each of these regulatory systems is divided into several interactive components: regulated expression of the growth factors, growth factor reception at the cell surface and intracellular action of the growth factors. In addition, the concept of regulated bioavailability and targeting of growth factors in the extracellular space is developed as an important control locus and area for future study. With regard to the IGF system, these components include two ligands--IGF-I and -II, both expressed in the porcine ovary--and the possibility of three receptors. IGF-I and the type I IGF receptor appear to be the most important in stimulating ovarian function and amplifying hormone action. In addition, the 'set-point' of the ovarian IGF system may be determined by the activity of several IGF-binding proteins (IGFBPs). At least four of these proteins are expressed in the pig ovary. Studies of their regulation and action in ovarian cells indicate that they can function as antagonists to FSH and the IGFs. However, preliminary evidence suggests a more dynamic model in which these proteins may direct the site and timing of IGF effects. There are fewer data on the EGF system. At least four EGF-related peptides are expressed in pig ovaries, but insufficient information is available to predict their physiological regulation. These peptides are potent mitogens for ovarian cells.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"186 1","pages":"117-25"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77254228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studies of uterine secretions and products of primary cultures of endometrial cells in pigs.","authors":"D. Davis, R. Blair","doi":"10.1530/biosciprocs.14.0010","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.0010","url":null,"abstract":"The uterus plays a central role in the reproductive biology of mammals. Adaptation of the uterus from an oviparous to a viviparous nature required changes that involved production of a uterine environment that could support the development of the embryo and fetus. Production of a suitable environment includes the synthesis and secretion of products by the uterine endometrium. However, the uterine endometrium is not a single homogeneous unit, but rather consists of several cell populations. Recent accomplishments in cell culture techniques provide a means for examining the contributions and secretory control of different endometrial cell populations. Furthermore, it is possible to recombine specific cell types to study their interaction. It is clear that the luminal epithelium, glandular epithelium and endometrial stroma produce different secretory products. Some secretions (for example uteroferrin) are secreted by only one cell type; others (for example prostaglandins, PGs) are secreted by all types of cell. There is much to be learned about the functions and regulations of endometrial secretions and there are important aspects of the role of the endometrium in pregnancy that present concepts do not address. For example, there is no explanation for the required synchrony between the embryo and uterus before day 10 and the implications of control of the uterine environment by progesterone from day 4 to day 10 are not understood. Almost all of the uterine secretory proteins are produced after day 10. In this review, we consider the protein and prostaglandin products from the different cell populations of the pig endometrium and propose a model to explain the integration of multiple sources of PGs and multiple regulators of PG secretion. Our purpose is to facilitate a more complete understanding of the individual uterine cell populations and a better understanding of how these cell types interact to function as a complete unit.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"76 1","pages":"143-55"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86392745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nuclear control of early embryonic development in domestic pigs.","authors":"R. Prather","doi":"10.1530/biosciprocs.14.002","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.002","url":null,"abstract":"In mammals, growing oocytes have characteristically high levels of RNA synthesis. After the initiation of meiosis, that is germinal vesicle breakdown, this RNA synthesis ceases. Although there is limited evidence for RNA synthesis by the zygote, significant amounts of RNA synthesis do not occur until a species-specific cell stage. In pigs, significant amounts of mRNA synthesis cannot be detected before the four-cell stage. There appear to be three qualitatively different periods of transcription during the four-cell stage. The first occurs during a short (< 2 h) G1 phase. The second, occurs after completion of DNA synthesis (S phase) about 16 h after cleavage to the four-cell stage, and the third occurs about 24 h after cleavage to the four-cell stage. Correlated with these changes in RNA synthesis are changes in nucleolar morphology, amino acid transport characteristics, protein production, mitochondrial morphology, and metabolism of the embryo. The mechanisms that regulate initiation of RNA synthesis in early mammalian embryos appear to repress transcription. A state of transcription permissiveness then follows that sets into motion the differentiation programme.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"598 1","pages":"17-29"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77841685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Culture of pig embryos.","authors":"R. Petters, K. Wells","doi":"10.1530/biosciprocs.14.005","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.005","url":null,"abstract":"Pig embryos can be cultured using a number of different strategies including complex approaches like culture in vivo in a surrogate oviduct (rabbit, sheep, mouse), culture in mouse oviducts in organ culture, and co-culture of embryos with cells in addition to simple approaches like culture in defined media or salt solutions. Addition of serum to medium has been of particular importance where blastocyst development and hatching are required. Pig conceptuses (day 10-15), embryonic discs or cell lines derived from conceptuses can be cultured in complex media like Eagle's minimal essential medium or Dulbecco's modified Eagle's medium with serum, although embryonic discs can be cultured in the absence of serum. In contrast, early stage pig embryos (one-cell to blastocyst) are best cultured in simpler media such as those used for mouse embryos. The media that have been used are all relatively similar in composition. They contain salts and one or more energy sources such as glucose, lactate, or pyruvate with BSA as a macromolecular component. Early attempts to culture pig embryos were not very successful, but some embryos did develop to the blastocyst stage. More recent reports indicate a much higher rate of development with relatively little or no change in media composition. Some workers have reported improved development in medium lacking glucose, which is consistent with findings with laboratory animals such as hamsters. Glutamine can serve as the sole exogenous energy source in medium lacking glucose, lactate and pyruvate. Addition of taurine and hypotaurine to culture medium enhances development of pig embryos in vitro. We suggest, where possible, adoption of a standard medium that could be used by different laboratories and, perhaps, with different species. Use of one medium for different species would simplify experimental protocols, enhance studies of comparative embryonic physiology and metabolism, and expedite transfer of information obtained in different species.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"3 1","pages":"61-73"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79661554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embryo-uterine interactions in pigs during week 2 of pregnancy.","authors":"R. Roberts, S. Xie, W. Trout","doi":"10.1530/biosciprocs.14.0012","DOIUrl":"https://doi.org/10.1530/biosciprocs.14.0012","url":null,"abstract":"The second week of pregnancy is a particularly critical period for embryonic survival in pigs. Within that time, conceptus oestrogen synthesis is initiated, spacing and final placement of conceptuses is completed, and the signal for extending the functional lifespan of the corpora lutea is received by the mother. There is also a marked increase in blood flow to the uterus and the uterine endometrium produces and secretes nutrient histotrophe. Conceptus-derived oestrogen has been implicated in many of these events. It is also during this period that the trophoblast elongates dramatically and the inner cell mass starts to differentiate into the embryo proper. Here, we critically review the evidence that oestrogen is the sole factor initiating long-term corpus luteum maintenance in pigs. We also review the functions and general properties of the major secretory proteins in histotrophe and the role of oestrogen in controlling their expression. It is now generally accepted that asynchrony within a litter underlies much of the losses of conceptuses that are otherwise genetically normal, but which are lagging in their development; however, the underlying mechanisms remain unclear. Here we hypothesize that oestrogenic compounds derived from more advanced conceptuses or provided prematurely, either by injection or in the diet, trigger a massive increase in uterine expression and secretion of retinol-binding protein laden with retinol. We propose that less developed, smaller conceptuses are least able to contend with the sudden exposure to this potential teratogen at a time when they are particularly susceptible to imbalance in retinol supply. Hence, even though their growth proceeds for a few days, their developmental potential is irrevocably compromised.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"2 1","pages":"171-86"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88460947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heterogeneous cell types in the corpus luteum of sheep, goats and cattle.","authors":"J. O'Shea","doi":"10.1530/BIOSCIPROCS.9.007","DOIUrl":"https://doi.org/10.1530/BIOSCIPROCS.9.007","url":null,"abstract":"Data on the structure, quantitation, origins and functions of the large luteal (LL) and small luteal (SL) cells of sheep, goats and cattle are reviewed. Both LL and SL cells show ultrastructural features consistent with a steroidogenic function. However, in addition to differences in size and shape, LL cells differ from SL cells primarily in possessing large numbers of secretory granules, suggesting an additional protein/polypeptide synthetic and secretory function. In sheep, morphometric estimates show that the corpus luteum (CL) contains approximately equal to 10 X 10(6) LL cells and approximately equal to 50-60 X 10(6) SL cells: individual LL cells are approximately equal to X 6 greater in volume than SL cells. During formation of the CL, granulosa and theca cells are incorporated, and evidence suggests that granulosa cells give rise to LL cells and theca cells to SL cells. However, SL cells, or cells of thecal origin, may also give rise to some LL cells. Both LL and SL cells produce progesterone in vitro. On a per cell basis, LL cells produce more progesterone than do SL cells, but SL cells show a much greater progesterone-secretory response to LH. Oxytocin is synthesized, and secreted in granule form, only by the LL cells, and relaxin, whose presence has been demonstrated convincingly only in cattle, also appears to be produced only by LL cells. The two types of luteal cell in ruminants therefore show major differences in function: the occurrence of any significant functional interaction remains to be established.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"26 1","pages":"71-85"},"PeriodicalIF":0.0,"publicationDate":"2019-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74454301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}