共查询到20条相似文献，搜索用时 62 毫秒
1.
2.
3.
4.
妊娠的建立和维持归因于胚体的信号和黄体对孕酮的产生,在反刍动物,胚体滋养层分泌的激素抑制子宫内膜产生前列腺素PGF2α。在发情周期的绵羊,孕酮下调子宫内膜腔上皮和子宫腺上皮孕酮受体基因的表达,并伴随着上皮雌激素受体和催产素受体的增加。在催产素的作用下,子宫开始分泌溶黄体作用的前列腺素F2α。在妊娠绵羊,孕体滋养层产生的干扰素可作用于子宫内膜而直接抑制雌激素受体基因和催产素受体基因的转录。孕酮、干扰素、胎盘催乳素和生殖激素共同组成了一个"作用网络"来调节子宫的功能分化和子宫腺的形态发生,从而维持绵羊妊娠。本文综述了绵羊妊娠识别、建立和维持的信号系统。 相似文献
5.
6.
7.
8.
Agnieszka BLITEK Ewa MORAWSKA-PUCINSKA Magdalena SZYMANSKA Jolanta KIEWISZ Agnieszka WACLAWIK 《The Journal of reproduction and development》2013,59(6):512-519
Transforming growth factor (TGF) β and its receptors are expressed at the
conceptus-maternal interface during early pregnancy in the pig. The present studies
were conducted to examine: (1) the effect of conceptus products on TGFβ1 mRNA
expression and protein concentration in the porcine endometrium using in
vivo and in vitro models, and (2) the effect of TGFβ1 on
proliferation of porcine trophoblast cells in vitro. During
in vivo experiments, gilts with one surgically detached uterine
horn were slaughtered on days 11 or 14 of the estrous cycle and pregnancy. For
in vitro studies, endometrial explants and luminal epithelial
(LE) cells co-cultured with stromal (ST) cells were treated with conceptus-exposed
medium (CEM). Moreover, porcine trophoblast cells were treated with TGFβ1, and the
number of viable cells was measured. On day 11, the presence of conceptuses had no
effect on TGFβ1 mRNA expression, but decreased the TGFβ1 protein concentration in the
connected uterine horn compared with the detached uterine horn. In contrast to day
11, on day 14 after estrus, TGFβ1 mRNA expression and protein content in the
endometrium collected from the gravid uterine horn were greater when compared with
the contralateral uterine horn. The treatment of endometrial slices with CEM resulted
in greater TGFβ1 mRNA expression and protein secretion. LE cells responded to CEM
with an increased TGFβ1 mRNA level. Moreover, TGFβ1 stimulated the proliferation of
day 14 trophoblast cells. In summary, porcine conceptuses may regulate TGFβ1
synthesis in the endometrium at the time of implantation. TGFβ1, in turn, may promote
conceptus development by increasing the proliferation of trophoblast cells. 相似文献
9.
10.
11.
12.
13.
14.
15.
16.
17.
Kikuchi M Nakano Y Nambo Y Haneda S Matsui M Miyake Y Macleod JN Nagaoka K Imakawa K 《The Journal of reproduction and development》2011,57(2):203-211
A factor responsible for progression to pregnancy establishment in the mare has not been definitively characterized. To identify factors possibly involved in the establishment of equine pregnancy, the endometrium was collected from day 13 (day 0=day of ovulation) cyclic and day 13, 19 and 25 pregnant animals. From initial subtractive hybridization studies, a calcium regulating factor, Stanniocalcin-1 (STC1) mRNA, was found as a candidate molecule expressed uniquely in the pregnant endometrium. Endometrial expression of STC1 mRNA was noted on day 19 and was markedly increased in the day 25 gravid endometrium. STC1 protein was found in the extracts of day 25 gravid endometrium and immunochemically localized in the uterine glands. In addition, STC1 protein was detected in uterine flushing media collected from day 25 pregnant mares. High concentrations of estradiol-17 β (E(2)) were detected in day 25 conceptuses. E(2) levels were much higher in the gravid endometrium than in other regions, whereas progesterone levels did not differ among the samples from different endometrial regions. Expression of STC1 mRNA, however, was not significantly upregulated in cultured endometrial explants treated with various concentrations of E(2) (0.01-100 ng/ml) with or without 10 ng/ml progesterone. These results indicate that an increase in STC1 expression appears to coincide with capsule disappearance in the conceptus, and suggest that STC1 from the uterine glands likely plays a role in conceptus development during the pregnancy establishment period in the mare. 相似文献
18.
Interferon tau (IFNT), a type I IFN produced by the conceptus trophectoderm, is the signal for maternal pregnancy recognition in ruminants. The purpose of this study was to investigate whether IFNT effected on the proliferation of ovine trophectoderm cells in an autocrine manner. Elongated ovine conceptuses (Days 15, Day 0 = day of mating) were collected for isolation of mononuclear ovine trophectoderm (oTr‐1) cells, and conceptuses (Days 15 and 20, n = 4 and 3, respectively) were collected for RNA extraction. We demonstrated that the IFNT receptor, IFNAR1, was expressed in trophectoderm of day 15 and 20 conceptuses. Interestingly, the ovine trophectoderm cell line oTr‐1 cultured in the presence of recombinant bovine IFNT (rbIFNT) displayed increased expressions of IFN‐stimulated genes (ISGs), such as IFN‐stimulated gene 15 (ISG15), 2‐5‐oligoadenylate synthetase 1 (OAS1) and bone marrow stromal cell antigen 2 (BST2). Meanwhile, the presence of rbIFNT in the culture media could promote the cell proliferation in a dose‐dependent manner. Furthermore, the connective tissue growth factor, which has diverse functions in cell proliferation and is involved in conceptus elongation, was upregulated in oTr‐1 cell by rbIFNT treatment in vitro. These data indicated that IFNT could act as an autocrine factor to regulate trophectoderm cell proliferation. 相似文献
19.
20.
Hansen PJ 《Reproduction in domestic animals》2011,46(Z3):18-30
The mammalian conceptus undergoes development in the face of a functional immune system. This characteristic of viviparity creates opportunities and perils for the conceptus. In the period up to hatching from the zona pellucida, the conceptus appears immunologically inert with low expression of major histocompatibility complex (MHC) genes and little evidence for alterations in the function of maternal immune cells. The conceptus may benefit from cytokines produced by leucocytes resident in the reproductive tract or by other cells of the reproductive tract. One cytokine in particular, colony-stimulating factor 2, can promote preimplantation development and cause changes in conceptus function that increase the likelihood that the conceptus develops to term. It is not clear whether activation of specific types of immune responses in early pregnancy can enhance the likelihood of pregnancy success. Semen deposition causes inflammation in the reproductive tract, but there is little evidence that this process is beneficial to pregnancy unless the uterus was exposed to a prior inflammatory event. Around the time of placentation, the period of immunological inertness of the conceptus is replaced by a period of immune activation caused by the expression of interferon genes in ruminants and pigs and MHC class I genes in invasive trophoblast of the horse. The large-scale changes in the endometrium that occur as a result are likely to play an important role to ensure continued development of the conceptus. In contrast, other immune responses generated as a result of disease in the reproductive tract or other tissues (mastitis) can lead to death of the conceptus. Because of this hazard, as well as the possibility that cell-mediated immune responses against the conceptus could occur, the immune system is regulated by both the mother and conceptus to reduce immune responsiveness during pregnancy. 相似文献