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环氧合酶(cyclooxygenase,Cox)是由花生四烯酸合成前列腺素的限速酶,而前列腺素在哺乳动物的生殖过程中起着很重要的作用。本试验采用RT—PCR方法对环氧合酶-1(Cox-1)及环氧舍酶-2(Cox-2)在早期妊娠兔子宫内膜中的表达进行了半定量研究和在早期胚胎中的表达定性研究。结果表明,Cox-1在早期妊娠兔子宫内膜中表达较平稳,呈组成型表达;在早期胚胎中各个时期均可以检测到Cox-1mRNA,表明它在早期胚胎发育过程中起作用。Cox-2在早期妊娠子宫内膜中的表达水平有很大差异,妊娠第l天表达水平较高,从第2天开始表达下降,到第6天表达又明显增加,第8天达到最高。Cox-2在囊胚之前的各个时期胚胎均未检测到,而在扩展胚泡和孵出胚泡中表达,Cox-2的时期特异性表达可能与兔胚泡孵出及胚胎着床等过程相关。  相似文献   

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白血病抑制因子(LIF)是一种多生物活性的细胞因子,研究表明,LIF在人及动物的子宫内膜的腺上皮细胞、妊娠期蜕膜及胎盘上均有表达;胚泡是动物生殖过程中的关键,一些细胞因子起重要作用,它们能够充当子宫内膜微环境的"局部调节者",LIF对哺乳动物胚胎发育到胚泡阶段具有一定的作用,LIF在子宫内膜中特异性表达,促进胚胎生长发育和启动胚泡植入;LIF在生殖周期中影响子宫的功能及调节子宫内膜生长,这可能与LIF作用于子宫使其能发生蜕膜反应有关;LIF通过与LIF受体及gp130蛋白作用而发挥重要的生物学功能。LIF在哺乳动物早期妊娠中的作用机制具有重要意义。文章对LIF及其受体与子宫内膜的关系做了综述。  相似文献   

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Histone deacetylase inhibitors (HDACis) can change the histone acetylation and significantly enhance the developmental competence of the pre‐implantation SCNT embryo. To select a proper histone deacetylase inhibitor to improve the success rate and potentially developmental ability of handmade cloning (HMC) embryos of miniature porcine, we compared the effect of two histone deacetylase inhibitors (SAHA vs. VPA) on HMC embryo development, their histone acetylation level and the expression level of relevant genes. The blastocyst rate and number of blastocyst cells of HMC embryos treated with SAHA (SAHA‐HMC) or VPA (VPA‐HMC) were significantly higher than those of control (Control‐HMC), respectively, but there were no significant difference between SAHA‐HMC and VPA‐HMC groups. In addition, the acetylation level (AcH4K8) of Control‐HMC and VPA‐HMC embryos at the blastocyst stage, respectively, was significantly lower than that of in vitro fertilized (IVF) and SAHA‐HMC embryos. However, the acetylation H4K8 of the blastocysts had no significant difference between SAHA‐HMC and the IVF groups. The SAHA‐HMC blastocysts indicated comparative expression levels of Oct4 and HDAC1 (histone deacetyltransferase gene) with those of IVF blastocysts. In contrast, the expression levels of Oct4 were lower and those of HDAC1 were higher in the VPA‐HMC and Control‐HMC blastocysts, respectively, compared to those of the IVF blastocysts. Our results demonstrated that the HMC embryos treated by SAHA could promote the pre‐implantation development and increase the levels of histone H4K8 acetylation and the expression of the OCT4 gene, yet decrease the expression of the HDAC1 gene to the comparable level of the IVF embryos. Our results proved that SAHA may be a better histone deacetylase inhibitor for porcine HMC compared to VPA, and furthermore, it may indicate that SAHA can effectively correct the abnormal histone acetylation during the HMC embryo development and subsequently improve the full‐term developmental potential of the HMC embryos after embryo transplantation.  相似文献   

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哺乳动物的胚胎植入是生殖过程的一个重要环节,是妊娠的关键。包括胚胎对母体子宫内膜的识别、黏附、侵入等过程。正常情况下,胚胎仅在一个极短的时间内有机会附着到子宫内膜上,即胚泡滋养层达到侵入状态,子宫内膜达到接受状态,且两者同步发生,胚泡才会成功植入。胚胎植入的成功必须具备许多条件,需要足够的激素分泌,合体滋养层细胞形成,以及胚泡与子宫内膜同步发育与相互配合等。这一过程的调控机制十分复杂,至今仍是生殖医学领域中尚未解决的问题。文章就胚胎植入的基本过程及其分子机制做简要综述。  相似文献   

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植入是胚胎与子宫内膜识别、接触并依附于子宫内膜上或进一步侵入、包埋于子宫内膜中的过程,是哺乳动物生殖生理的重要环节,这一过程对于胚胎能够在子宫持续的发育并最终获得成功的妊娠是必需的。成功的植入需要同步发育的正常胚胎、容受性的子宫内膜及母胎的和谐对话来实现。胚胎植入过程复杂而短暂,参与调控的因素有很多,包括microRNA。论文介绍了与植入相关microRNA的最新研究进展,包括microRNA对胚胎发育、子宫内膜的容受性等方面的作用,将为我们理解植入机制提供新的视角。  相似文献   

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Three separate trials of bovine embryo transfers were performed consisting of 32, 41 and 33 transfers, respectively, to examine the effects of (a) the developmental stage of in vitro‐derived blastocysts, (b) the amount of interferon‐τ (IFN‐τ) they secreted during culture and (c) the cyclic stage of the recipient at the time of transfer on the probability of establishment of pregnancy. One blastocyst was transferred into the ipsilateral uterine horn to the CL. At the time of transfer, blastocysts were classified into one of three developmental stages (early blastocyst, blastocyst and expanded blastocyst) and the cyclic stage of each cow was assessed (?12 h, on time, +12 h, +24 h, >24 h). Prior to the second and third trials, blastocysts were individually cultured for 24 h in 50 μl medium droplets and the IFN‐τ concentration in the droplet was determined. Logistic regression analyses revealed that expanded blastocysts had a significantly higher likelihood of establishing pregnancy (p = 0.009), and that there was a significant interaction with the cyclic stage of the recipient in this group with lower rates of pregnancy resulting from decreasing synchrony with the recipient (p = 0.033). IFN‐τ secretion during culture was significantly higher in expanded blastocysts than in the other two groups (p < 0.05). A significant effect of the pre‐transfer level of IFN‐τ secretion was found only in the ‘Blastocyst’ group where transfer of embryos with lower IFN‐τ production prior to transfer resulted in higher pregnancy rates (p = 0.047). These results demonstrate that IFN‐τ secretion may be a useful tool to predict pregnancy outcome, but only within certain developmental stages.  相似文献   

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Leucemia inhibitory factor (LIF) is involved in various reproductive processes, including sperm development, regulation of ovulation, as well as blastocyst formation, hatching and implantation in embryos. Moreover, LIF has also been shown significantly to enhance the blastocyst formation rates of bovine embryos, a finding that remains controversial. Our purpose was to investigate time‐dependent effect of LIF on bovine embryo culture, especially in terms of addition timing. Presumptive zygotes were cultured in five different groups. In this study, 100 ng/ml LIF was added to the culture medium were as follows; control: SOF alone, group A: at day 0 (fertilization day), group B: at day 4 post‐insemination (p.i.), group C: at day 4 to 7 (p.i. before vitrification) and group D: at day 8 (p.i. after thawing). Addition of LIF to the culture medium at day 4 significantly increased the percentage of blastocyst rate when compared day 0, day 4 at 6/7 and control group (41.8% versus 24.3%, 19.7%, 34.6%). In conclusion, the addition of LIF only on day 4 (p.i.) to the culture medium was found to be beneficial for bovine embryonic development based on several measures, including blastocysts rate, re‐expansion rate and cellular cryotolerance after vitrification.  相似文献   

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This study was conducted to evaluate the effectiveness of forced collapse of the blastocoel before slow‐rate freezing and vitrification of bovine blastocysts. Cryopreservation of bovine blastocysts has been proposed as a tool to improve the feasibility of cattle production using the embryo transfer technique. However, the low efficiency of frozen–thawed embryos survival and further development is a crucial problem. In this study, bovine in vitro and in vivo blastocysts were slow‐rate frozen and vitrified after forced blastocoele collapse (FBC) of the blastocyst cavity by puncturing the blastocoele with a pulled Pasteur pipet. Differences in the developmental potential of frozen–thawed blastocysts derived from FBC and non‐FBC groups were found in both slow‐rate freezing and vitrification. Furthermore, we found that the total cell number of blastocysts in FBC groups was increased and the index of apoptosis in FBC groups was decreased. Consistent with these results, real‐time RT‐PCR analysis data showed that expression of the anti‐apoptotic Bcl‐XL gene was significantly increased by FBC groups, whereas expression of the pro‐apoptotic Bax gene was significantly decreased by FBC groups. Our results also showed that pregnancy outcomes in both slow‐rate frozen and vitrified bovine in vivo blastocysts could be improved by reducing the fluid content after FBC of the blastocyst cavity. Therefore, we suggest that FBC of the blastocyst cavity with a pulled Pasteur pipet is an effective pre‐treatment technique for both slow‐rate freezing and vitrification of bovine blastocysts.  相似文献   

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This study was conducted to examine the potential for implantation and sustainable fetal development of mouse embryos cultured from the pronuclear to blastocyst stage. Pronuclear embryos from ICR mice (Harlan Sprague‐Dawley) were cultured in Sydney IVF sequential media (Cook) to the blastocyst stage in medium only or co‐cultured with autologous cumulus cells. We also experimented with co‐culture in 100 µL drops. Drop co‐culture produced blastocyst formation rates with a mean of 47.0%, which was significantly higher (P < 0.05) compared to embryos cultured in identical culture conditions except without cumulus cells at 27.3%. Blastocysts obtained in vitro in Cook medium only and co‐cultured in Cook medium with cumulus cells were transferred to pseudopregnant females of ICR strain. The day of blastocyst transfer into surrogate females was designated as post‐transfer of blastocyst day 1 (PT 1). The implantation and fetal development was compared to embryo transfer of in vivo derived blastocysts, which served as controls. There were no statistical differences for implantation and fetal development rates for blastocysts cultured in vitro in either Cook medium only or co‐culture in Cook medium with cumulus cells compared to in vivo‐derived blastocysts. The advantage of the co‐culture system is in generating more blastocysts available for transfer.  相似文献   

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[目的]为了评估胚胎质量和发育阶段对奶牛胚胎移植妊娠率的影响。[方法]使用63头青年奶牛作为供体进行超数排卵,评估回收胚胎质量和发育阶段。选择334头青年奶牛作为受体鲜胚移植不同质量和发育阶段胚胎。对胚胎质量分布、发育阶段分布、不同质量胚胎和不同发育阶段胚胎移植30 d妊娠率进行统计分析。[结果]可用胚胎中A级胚胎比例(60.78%)显著高于B级和C级胚胎比例(36.70%和2.52%)(P<0.05);致密桑椹胚比例(54.36%)显著高于早期囊胚,囊胚和扩张囊胚比例(18.35%,25.0%和2.29%)(P<0.05)。A级和B级胚胎移植30 d妊娠率(63.55%和64.35%)显著高于C级胚胎移植30 d妊娠率(44.44%)(P<0.05);致密桑椹胚、早期囊胚、囊胚和扩张囊胚移植30 d妊娠率差异不显著(P<0.05),早期囊胚、囊胚移植30 d妊娠率高于致密桑椹胚、扩张囊胚移植30 d妊娠率(P<0.05)。[结论]选择不同发育阶段的A级和B级胚胎能够获得较高胚胎移植妊娠率,增加早期囊胚和囊胚阶段胚胎移植数量能够提高胚胎移植妊娠率。  相似文献   

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The aim of this study was to evaluate the developmental kinetics of cats' blastocysts in connection with their morphology and blastomeres allocation to trophoblast or embryoblast cells. We examined gross blastocyst morphology and the total number of blastomeres together with its allocation to inner cell mass (ICM) or trophectoderm (TE) cells in pre‐implantation feline embryos obtained from 6th to 9th day of in vitro culture. From all the investigated embryos, 61.8% developed to early blastocyst, 37.4% to full and 7.6% to hatching blastocyst stage. The total cell number (TCN) varied form 58 cells in early day 6 to 245 in hatching day 8 blastocyst, with the mean 84.9 cells in early, 156.7 in full, and 204.4 in hatching ones. Day 8 blastocyst had the highest number of total cells, together with the highest mean number of ICM regardless of its morphological assessment. Early blastocyst (apart from day 6) had the highest number of arrested cells, while dead cells were the highest in full day 9 blastocyst. More data about the relationship between blastocyst development and morphology would facilitate the selection of optimal blastocysts for further procedures.  相似文献   

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Leukemia inhibitory factor (LIF) is essential for embryo implantation in mice and plays an important role in other mammals including humans. Intraperitoneal (i.p.) injections with anti-LIF antibody (7.5 μg/g body weight, 3 times) between D3 (D1 = day of vaginal plug detection) and D4 effectively blocked embryo implantation; complete inhibition was achieved in C57BL/6J mice, and implantation was dramatically reduced in ICR mice (reduced to 27%). Normal rabbit IgG used as the control did not disturb embryo implantation. Anti-LIF antibody was localized not only in the stroma, but also in the luminal epithelium and the glandular lumen after i.p. injections. Growth-arrested blastocysts were recovered from the uterus without any implantation sites in both strains. Blastocysts made contact with the LE on the antimesometrial side; however, uterine stromal cells did not undergo secondary decidual reaction, and the uterine lumen was open, even at D7. Several regions of decidualization in ICR mice treated with anti-LIF antibody were smaller than those of the control, and development of blastocysts was delayed. The expression of LIF-regulated genes, such as immune-responsive gene-1 and insulin-like growth factor binding protein-3, was significantly decreased in C57BL/6J mice treated with anti-LIF antibody compared with the control, but not in ICR mice. The present study demonstrated that simple ip injections of an antibody are sufficient to block one of the important factors involved in embryo implantation in mice, and this method should also be easily applicable to the investigation of other factors involved in implantation.  相似文献   

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