Journal of reproduction and fertility. Supplement最新文献_第3页

Physiological role of seminal components in the reproductive tract of the female pig. 母猪生殖道精液成分的生理作用。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.13.009

R. Claus

{"title":"Physiological role of seminal components in the reproductive tract of the female pig.","authors":"R. Claus","doi":"10.1530/biosciprocs.13.009","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.009","url":null,"abstract":"In many species the appearance of oestrus is sufficient to ensure that the time of ejaculation, sperm transport and capacitation are balanced with the time of ovulation. In the pig these phenomena vary considerably and require additional regulatory mechanisms which are partly explained by seminal components. Boar semen is rich in oestrogens (up to 11.5 micrograms/ejaculate). Infusion of saline with the addition of oestrogens in physiological amounts increased the myometrial contraction frequency up to 2.5-fold. This effect is explained by a release of PGF-2 alpha immediately after oestrogen infusion. Such an infusion also raises peripheral oestrogen concentrations and an effect on LH release can be demonstrated. Additionally, PGF-2 alpha is measurable in uterine vein plasma after oestrogen infusion and is transferred into the follicular fluid. The effect of oestrogens on LH and follicular PGF-2 alpha is likely to contribute to the timing of ovulation in response to mating. A specific protein of Mr 100,000-110,000 has been detected in boar seminal plasma and it exerts a strong immunosuppressive effect. This protein may be involved in a protection of spermatozoa but also of early embryos against female immunological attack. The addition of such specific compounds to AI doses, in which seminal plasma is diluted, may improve prolificacy.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"40 1","pages":"117-31"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90858327","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}

引用次数: 101

Regulation of conceptus development and attachment in pigs. 猪概念发育和依恋的调控。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.15.0010

R. Geisert, J. Yelich

{"title":"Regulation of conceptus development and attachment in pigs.","authors":"R. Geisert, J. Yelich","doi":"10.1530/biosciprocs.15.0010","DOIUrl":"https://doi.org/10.1530/biosciprocs.15.0010","url":null,"abstract":"Implantation/placentation in domestic pigs is preceded by synthesis of oestrogen by the conceptus to maintain functional corpora lutea throughout pregnancy and a rapid morphological transformation of conceptuses from spherical to long filamentous thread-like structures. Initial conceptus expansion, reaching a metre in length, not only delineates the surface area for placental attachment, but also provides the mechanism for delivery of oestrogen to signal events necessary for placentation throughout the uterine horn. Timing for conceptus gene expression to induce trophoblast expansion and attachment in pigs is temporally associated with downregulation of progesterone receptors and increase in oestrogen receptors within the uterine epithelium. Within the confines of the uterine lumen, pig conceptuses normally do not erode or invade through the uterine epithelial surface. However, the pig conceptus possesses extensive proteolytic activity as it is highly invasive outside the uterine lumen of the pig. Initial release of oestrogen by the elongating pig conceptus induces endometrial release of cytokines and a variety of protease inhibitors. Recently, endometrial expression for the inter-trypsin inhibitor (I alpha I) family of protease inhibitors has been detected in the pig endometrium during conceptus elongation and attachment. It is possible that I alpha Is may function to inhibit trophoblast invasion and also serve as targets for adhesion molecules, such as integrins and heparin, to aid in placental attachment to the uterine epithelium.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"48 1","pages":"133-49"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88239913","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}

引用次数: 176

Assessment of boar sperm function in relation to freezing and storage. 猪精子功能与冷冻和储存的关系评价。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.15.0015

W. Holt, A. Medrano

引用次数: 27

Manipulation of gametes and embryos in the pig. 对猪配子和胚胎的操作。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.12.008

J. Robl, N. First

{"title":"Manipulation of gametes and embryos in the pig.","authors":"J. Robl, N. First","doi":"10.1530/biosciprocs.12.008","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.008","url":null,"abstract":"Several manipulation techniques including nuclear injections, nuclear transplantation, embryo splitting, chimaera production and sperm injection are discussed with special reference to their application in the pig. The nuclear injection technique is likely to be of greatest use for gene transfer. Gene transfer is feasible for pig embryos, but it is very inefficient. Efficiencies of various steps in the successful production of transgenic offspring as summarized from several published references are as follows: immediate survival of embryos following injection (60%), offspring produced from injected embryos (15%), offspring with an integrated foreign gene (24%) and offspring expressing the integrated foreign gene (60%). The overall efficiency is about 1%. Potential uses for nuclear transplantation are for the production of gynogenetic and androgenetic embryos and for cloning embryos. The feasibility of producing androgenetic and gynogenetic embryos will depend on whether in the pig, as in the mouse, the paternal and maternal genomes function differently. The feasibility of cloning by nuclear transplantation will depend upon the timing of developmental events in pig embryos and the development of methods for reprogramming nuclei. Pig embryos have been cloned by embryo splitting. Chimaera production and fertilization by sperm injection are likely to be feasible for pig embryos but have not yet found application.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"90 1","pages":"101-14"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73319935","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}

引用次数: 15

Control of follicular development during and after lactation in sows. 母猪泌乳期间和之后卵泡发育的控制。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.12.003

J. Britt, J. D. Armstrong, N. M. Cox, Nancy M. Esbenshade

{"title":"Control of follicular development during and after lactation in sows.","authors":"J. Britt, J. D. Armstrong, N. M. Cox, Nancy M. Esbenshade","doi":"10.1530/biosciprocs.12.003","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.003","url":null,"abstract":"Follicular development during early lactation in the sow is characterized by a large population of small-sized follicles and a small population of medium-sized follicles. As lactation progresses there is a gradual shift in number of follicles into medium- or large-sized categories and the percentage of follicles classified as atretic declines. Weaning at birth often leads to aberrant follicular development, apparently because the positive feedback response of LH to oestradiol does not occur during the first week post partum. Secretion of LH during lactation is primarily controlled by suckling intensity of the litter while FSH is controlled by a nonsteroidal ovarian factor, presumably inhibin. Suckling apparently limits secretion of GnRH and weaning leads to an increase of GnRH within the hypothalamus coincident with an increase of LH in the anterior pituitary and plasma and increased follicular growth. Follicular development during both lactation and post-weaning anoestrus can be stimulated by exogenous gonadotrophins and pulsatile administration of GnRH. Factors such as nutrition, season, boar exposure, litter size and split weaning affect follicular development during lactation and after weaning, probably because they affect secretion of LH.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"27 1","pages":"37-54"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74651723","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}

引用次数: 114

Effectiveness of genetic selection for prolificacy in pigs. 猪繁殖能力遗传选择的有效性。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.12.0010

M. Bichard, P. J. David

{"title":"Effectiveness of genetic selection for prolificacy in pigs.","authors":"M. Bichard, P. J. David","doi":"10.1530/biosciprocs.12.0010","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.0010","url":null,"abstract":"This paper attempts to summarize and discuss the new evidence on the effectiveness of selection for prolificacy. In recent years selection between lines, and the adoption of formal cross-breeding programmes, have led to considerable improvements at a commercial level. Within-line selection has not been tackled seriously except in a few experiments. The mainly negative results from these should not lead to the conclusion that progress is impossible, but rather that it needs larger resources, applied consistently for several generations, to overcome the inherent problems. There are now many estimates of genetic parameters, based on large data sets, and these have helped to clear up some of the confusion resulting from previous inadequate material. A heritability of around 0.1, repeatability of 0.15, and fairly high genetic correlations between successive records seem justified. The negative environmental effect of being reared in a large litter is frequently present, but there is no good reason why this should seriously affect attempts to improve the trait by selection. Information from a candidate's relatives other than its dam can undoubtedly increase the accuracy with which its breeding value is estimated, but the routine use of such data in practical programmes is not straightforward. Prolificacy is only one group of traits contributing to net economic worth. The need to strike a balance between all relevant traits is explored in the particular context of a scheme based on hyperprolific sows. Finally, selection can only have lasting and cumulative effectiveness if it is applied at the top of a pyramid of improvement. Both culling and selection of replacement gilts within the commercial sector are largely irrelevant.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"50 1","pages":"127-38"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85353056","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}

引用次数: 26

How does embryo manipulation fit into present and future pig reproduction? 胚胎操作如何适应现在和未来的猪繁殖?

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.12.007

C. Polge

{"title":"How does embryo manipulation fit into present and future pig reproduction?","authors":"C. Polge","doi":"10.1530/biosciprocs.12.007","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.007","url":null,"abstract":"Available techniques for the collection and direct transplantation of pig embryos are simple and efficient and could be used for the expansion of new lines, for increasing selection pressure in nucleus herds and for extracting healthy stock from a diseased source. However, the reduced viability of pig embryos during culture in vitro and the inability as yet to preserve them by deep-freezing impose limits to the use of embryo transplantation for the export or import of potential breeding stock. The efficiency of breeding schemes could be improved by the sexing of embryos and the possibility of producing genetically identical twins or quadruplets by micromanipulation of embryos should improve the efficiency of animal experimentation. Chimaerism may be used to rescue embryos of a non-viable genotype such as parthenotes or those derived by hybridization, but the greatest revolution in pig breeding may be brought about by the introduction of foreign cloned genes into eggs and the production of transgenic animals. Eggs at an appropriate stage for microinjection may be provided in the future by techniques for the maturation and fertilization of oocytes in vitro. Animal breeders should be aware of the potential impact of techniques for the manipulation of eggs and embryos on future developments in animal production.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"33 1","pages":"93-100"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83909169","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}

引用次数: 13

Maturation of pig oocytes in vivo and in vitro. 猪卵母细胞在体内和体外的成熟。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.13.0014

R. Moor, M. Mattioli, J. Ding, T. Nagai

{"title":"Maturation of pig oocytes in vivo and in vitro.","authors":"R. Moor, M. Mattioli, J. Ding, T. Nagai","doi":"10.1530/biosciprocs.13.0014","DOIUrl":"https://doi.org/10.1530/biosciprocs.13.0014","url":null,"abstract":"In this review the concept that the origins of embryonic failure occur during oocyte development is explored. The four factors that determine oocyte viability, namely a normal growth phase, adequate follicle cell support during maturation, the completion of intracellular reprogramming before fertilization and the functioning of oocyte surveillance mechanisms, form the four sections of this review. The viability of pig oocytes at the end of the growth phase is compromised by presumptive spontaneous meiotic progression and by morphological heterogeneity. Determining the percentage and identity of viable dictyate oocytes, and identifying the reasons for the loss of viability, are key areas of future investigation. Although the requirement for follicle cell support during maturation is already established, little is yet known about the underlying signals and their transmission to the oocyte. The analysis of the action and nature of somatic signals will provide the foundation for further advances in the maturation of oocytes in vitro. Signalling cascades in oocytes control both the translation of masked mRNA and the modification and spatial localization of resultant proteins. The interdependent nature of this control system explains why inappropriate signals during maturation lead to subsequent embryonic mortality. Chromosomal errors during meiosis and early mitosis accumulate because of the leaky nature of the checkpoint system during the maternally regulated part of development: effective cell cycle surveillance is established only after the activation of the embryonic genome. In summary, we emphasize that the quality of the dictyate oocyte and the provision of appropriate signals in vitro are the principal determinants of maturational success.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"111 1","pages":"197-210"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85773557","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}

引用次数: 118

Maturation of ovarian follicles in the prepubertal gilt. 青春期前后备母猪卵巢卵泡的成熟。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.12.002

R. Christenson, J. Ford, D. Redmer

{"title":"Maturation of ovarian follicles in the prepubertal gilt.","authors":"R. Christenson, J. Ford, D. Redmer","doi":"10.1530/biosciprocs.12.002","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.002","url":null,"abstract":"The processes of follicle development and puberty are closely related, and both are associated with maturation of the hypothalamic-pituitary-ovarian axis. Prenatal development of the ovary is independent of gonadotrophic stimulation. Beyond 60 days of age (postnatally), tertiary follicles develop and gonadotrophins begin to influence ovarian follicular development. Negative feedback regulation of pituitary gonadotrophins by ovarian secretions develops between 60 and 100 days of age. In the prepubertal gilt, no consistent changes in peripheral FSH, oestrogen or progesterone concentrations have been identified which are associated with recruitment of the first set of preovulatory follicles. Whether LH secretion increases before this recruitment remains equivocal. Few details are available on how gonadotrophic hormones stimulate ovarian function in the prepubertal gilt. On the basis of a follicular maturation model that has been described for the rat, the actions of FSH, LH and oestrogens on follicular cell receptors and the regulation of aromatase activity seem paramount. Aromatization of androgens to oestrogens has been proposed as a central regulator for follicular maturation. In the prepubertal gilt, a selective increase in peripheral FSH concentration occurs on Day 1 after unilateral ovariectomy, followed by significant increases in ovarian venous concentrations of oestradiol and inhibin on Days 2 and 4 and compensatory growth as measured by follicular fluid volume on Days 2, 4 and 8. Administration of pig follicular fluid to the prepubertal gilt during and after unilateral ovariectomy suppresses compensatory ovarian hypertrophy by mechanisms yet to be determined. In pigs a number of intraovarian factors have been identified, but there is little information on how these factors regulate follicular recruitment and growth. The factor(s) that prevents ovarian follicles in the prepubertal gilt from progressing to ovulation after acquiring the ability to ovulate in response to exogenous gonadotrophins remains unknown.","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"50 1","pages":"21-36"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82439208","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}

引用次数: 50

Effect of migration, distribution and spacing of pig embryos on pregnancy and fetal survival. 猪胚胎迁移、分布和间距对妊娠和胎儿存活的影响。

Journal of reproduction and fertility. Supplement Pub Date : 2020-10-12 DOI: 10.1530/biosciprocs.12.004

P. Dziuk

{"title":"Effect of migration, distribution and spacing of pig embryos on pregnancy and fetal survival.","authors":"P. Dziuk","doi":"10.1530/biosciprocs.12.004","DOIUrl":"https://doi.org/10.1530/biosciprocs.12.004","url":null,"abstract":"Pig embryos enter the uterus from the oviduct about 48 h after ovulation at about the 4-cell stage. They remain near the tip of the uterine horn until about Day 6 when they migrate towards the body of the uterus. By Day 9 some embryos have entered the horn opposite the one of origin and continue migrating until Day 12. At Day 12 embryos can no longer successfully move to a different site. The critical signal for recognition of pregnancy occurs at Day 12 at the same time that embryos are elongating at a rapid rate. The distribution of embryos throughout the length of the horns has occurred by this time and spacing accompanied by uterine growth takes place. The speed of migration is not influenced by the number of embryos but may be affected by secretions from the embryos acting on the uterus. A significant section of unoccupied uterus at Day 12 will prevent continuance of pregnancy regardless of the number of embryos present in the occupied section. When the number of embryos is so few as to not occupy the uterus fully, pregnancy will not continue. Removal of embryos from a significant section of the uterus after Day 14 does not stop an existing pregnancy. Embryos are spaced nearly equidistant from each other with the absolute space between fetuses dependent on the total uterine space available. The position of the fetus in the uterus affects the spacing between fetuses; fetuses at the tip of the horn before Day 25 have the greatest space with the space decreasing from the tip to the body.(ABSTRACT TRUNCATED AT 250 WORDS)","PeriodicalId":16956,"journal":{"name":"Journal of reproduction and fertility. Supplement","volume":"10 1","pages":"57-63"},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78984655","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}

引用次数: 116