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体外胚胎生产作为一项高效的辅助生殖技术,对优质种质资源的保存利用及遗传改良具有重要意义。但与体内生产胚胎相比,体外生产胚胎在培养过程中出现生长发育缓慢、卵裂率低、凋亡比例增加等问题,移植后伴随着胎盘肥大、孕期延长等问题,还可能出现早产、出生体重降低、巨胎综合征(LOS)等,这与基因表达异常和表观遗传修饰异常有重要关系。文章简单回顾了近年来表观修饰学在体内、外生产胚胎的研究进展,主要介绍了印记基因的表观修饰、DNA甲基化及组蛋白乙酰化在哺乳动物体内、外生产胚胎之间的差异,简述了微阵列技术在体内、外生产胚胎之间的应用,以期找到导致体内、外胚胎质量差异的关键印记基因及其作用途径,探讨体外生产胚胎质量低于体内胚胎的原因,进而改善体外胚胎生产体系。 相似文献
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印记基因在调控哺乳动物的众多生命进程中发挥着重要作用,尤其是在生命形成初期,印记基因通过表观遗传修饰决定等位基因的表达和沉默,调节着胚胎和胎盘的生长发育。印记基因在胎盘和胚胎中的表达紊乱与胎儿生长受限、发育停止以及甲状腺脱毒症等密切相关,因此深入探索印记基因对胚胎和胎盘发育的调节机理对于哺乳动物胎儿宫内发育迟缓、出生缺陷以及后期疾病的预防具有重要的指导意义。本文综述了印记基因的主要特点、性腺中印记的擦除、重建与表观遗传修饰及印记基因调控哺乳动物胚胎和胎盘发育的最新研究进展。 相似文献
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玻璃化冷冻作为一种操作简单、成功率高的细胞保存方式具有诸多优点，广泛应用于农业、医学、生物等领域。但相较于新鲜卵母细胞，玻璃化冷冻后的卵母细胞仍存在许多问题，如玻璃化冷冻后的卵母细胞妊娠率和产活仔率低于新鲜的卵母细胞、基因表达异常等。表观遗传学是研究基因在核苷酸序列不发生改变的情况下基因表达的可遗传变化的一门学科。表观遗传修饰在不改变DNA序列的情况下使基因和环境之间产生相互作用。在体外胚胎生产过程中，外界环境因素会对表观遗传修饰造成影响。作者从表观遗传学方面综述了玻璃化冷冻对哺乳动物MⅡ期卵母细胞DNA和全基因组甲基化、组蛋白甲基化和乙酰化、磷酸化及泛素化、基因印迹、microRNA的影响，以及玻璃化冷冻MⅡ卵母细胞后表观遗传修饰的改变对转录过程中基因的表达影响，为揭示并调控玻璃化冷冻卵母细胞后表观遗传修饰事件、进一步提高玻璃化冷冻后卵母细胞的质量提供参考。 相似文献
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小鼠早期胚胎发育过程中的DNA去甲基化 总被引：1，自引：0，他引：1
表观遗传修饰在基因转录与表达、细胞生长与分化以及动物个体正常发育等过程中都具有重要的调控作用。表观遗传修饰发生异常,会引起机体生长发育中的各种异常。哺乳动物从精卵受精到附植前的胚胎早期发育阶段会发生重要的表观遗传重编程,主要包括DNA甲基化和组蛋白修饰。精卵受精后DNA发生主动和被动2种方式的去甲基化。本文主要综述了与DNA甲基化相关的蛋白和早期胚胎发育过程中的去甲基化机制,并对小鼠附植前胚胎发育过程中的DNA甲基化的动态变化进行了详细的论述。 相似文献
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胚胎干细胞是未分化的具有增殖和自我更新能力的细胞,并且能分化成所有类型的体细胞以及生殖细胞。它们提供了早期胚胎分化的体外模型,也是基因操作的重要靶细胞。禽类多能性干细胞培养最重要的应用领域是以干细胞体外遗传修饰、鉴定为技术平台的家禽转基因技术。通过此技术对禽类基因进行遗传修饰与操作,在胚胎发育基础研究、转基因禽类生产及家禽育种等方面有巨大的应用前景。但是禽类多能性干细胞培养的许多基本问题仍亟待解决,如探索其建系的培养条件、揭示其维持多能性和增殖能力的分子机制等。文章综述了禽类多能性干细胞的分离方法、体外分化能力、嵌合体形成以及基因修饰方面的研究进展及目前的研究局限。 相似文献
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组蛋白修饰是控制各种生物活性的基本表观遗传过程。在哺乳动物卵母细胞成熟和早期胚胎发育中，组蛋白修饰调控减数分裂、胚胎发育以及细胞分化等过程。乳酸是糖酵解的最终产物，也是一种多功能信号分子。最近研究发现，乳酸通过组蛋白赖氨酸残基的乳酸化来促进基因的表观遗传调控，并且发现乳酸是组蛋白赖氨酸乳酸化的前体，从而刺激染色质的基因转录。本文综述了乳酸盐和乳酸盐诱导的组蛋白乳酸化在胚胎发育以及子宫内膜容受性等生殖过程中的作用，为进一步建立体外胚胎生产体系以及提高哺乳动物繁殖能力具有重要意义。 相似文献
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基因组印记是一种表观调控机制,在哺乳动物的发育中具有重要作用。印记基因是仅一方亲本来源的同源基因表达,而来自另一亲本不表达的一种基因。近年来,印记基因被广泛研究。印记基因分为父系印记基因和母系印记基因,其表达具有组织特异性,而且在胚胎不同发育阶段的表达也具有一定差异,胚胎期的营养水平也影响印记基因的表达。DNA甲基化在调控印记基因的表达中起重要作用,影响细胞核移植过程细胞的表观重编程,并影响胎盘及内脏器官的正常发育;基因印记模式的改变也可以引起甲基化的改变进而导致基因印记的丢失等。本文综述了近年来关于牛的印记基因的研究进展情况,为印记基因的后续相关研究工作提供借鉴。 相似文献
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Kikuchi K 《The Journal of reproduction and development》2004,50(1):21-28
The establishment of in vitro embryo production (IVP) system in pigs enables us to generate viable embryos with a quality equal to that of in vivo derived embryos. This technology contributes not only to developments in reproductive physiology and agriculture but also to biotechnologies for producing cloned or genetically modified pigs. The birth of piglets from in vitro matured and fertilized embryos at the two- to 4-cell stage was first achieved about 10 years ago, but it was only quite recently that piglets were produced after the transfer of IVP blastocysts. This improvement to the blastocyst stage of the in vitro culture system after in vitro maturation and fertilization can be expected to play a part in the development of an advanced IVP system. Here, we discuss the developmental ability of porcine embryos produced by our improved IVP system and the utilization of this technique in the new biotechnology. 相似文献
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Bovine somatic cell nuclear transfer (SCNT) embryos can develop to the blastocyst stage at a rate similar to that of embryos produced by in vitro fertilization. However, the full‐term developmental rate of SCNT embryos is very low, owing to the high embryonic and fetal losses after embryo transfer. In addition, increased birth weight and postnatal mortality are observed at high rates in cloned calves. The low efficiency of SCNT is probably attributed to incomplete reprogramming of the donor nucleus and most of the developmental problems of clones are thought to be caused by epigenetic defects. Applications of SCNT will depend on improvement in the efficiency of production of healthy cloned calves. In this review, we discuss problems and recent progress in bovine SCNT. 相似文献
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María Pilar Viudes‐de‐Castro Francisco Marco‐Jimnez Alba Ms Pellicer Ximo García‐Domínguez Amparo M. Talavn Jose Salvador Vicente 《Reproduction in domestic animals》2019,54(4):696-701
Superovulation protocols are designed to achieve maximum embryo yields. Nevertheless, ovarian response control and the quality of obtained embryos are still a challenge. On the other hand, to save the superovulated embryos until their subsequent use, it is usual to cryopreserve them, so it is also crucial to assess their cryotolerance. The aim of this study was to compare the efficacy of a single injection of corifollitropin alfa (FSH‐CTP) alone or supplemented with human chorionic gonadotropin (hCG) and to determine the impact of this stimulation on in vitro and in vivo development of fresh or devitrified embryos. Our outcomes showed that ovulation rate and recovered embryos were significantly increased when hCG was used. In vitro development of fresh and devitrified embryos and survival at birth were not significantly affected by superstimulation treatment. Results of this study suggest that a single injection of long‐acting FSH‐CTP supplemented with hCG can be effectively used in rabbits to elicit an increase in ovulation rate and number of recovered embryos. Furthermore, we demonstrated that hCG supplementation had no negative effects in embryo cryosurvival and development, showing similar survival rate at birth than FSH‐CTP alone group. 相似文献
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Jesus Manuel Palomino Gabriela F. Mastromonaco Miriam P. Cervantes Reuben J. Mapletoft Muhammad Anzar Gregg P. Adams 《Reproduction in domestic animals》2020,55(1):54-63
Two experiments were done using a two-by-two design to determine the effects of season and superstimulatory protocol on embryo production in wood bison. In Experiment 1 (in vivo-derived embryos), ovarian superstimulation was induced in female bison during the ovulatory and anovulatory seasons with either two or three doses of FSH given every-other-day (FSH × 2 vs. FSH × 3, respectively). Bison were given hCG to induce ovulation, inseminated 12 and 24 hr after hCG, and embryos were collected 8 days after hCG (n = 10 bison/group). In Experiment 2 (in vitro embryo production), ovarian superstimulation was induced in female bison during the ovulatory and anovulatory seasons with two doses of FSH, and in vivo maturation of the cumulus–oocyte complexes (COC) was induced with hCG at either 48 or 72 hr after the last dose of FSH. COC were collected 34 hr after hCG, and expanded COC were used for in vitro fertilization and culture. In Experiment 1, the number of follicles ≥9 mm, the proportion of follicles that ovulated, the number of CL, and the total number of ova/embryos collected did not differ between seasons or treatment groups, but the number of transferable embryos was greater (p < .05) in the ovulatory season. In Experiment 2, no differences were detected between seasons or treatment groups for any end point. The number of transferable embryos produced per bison was greatest (p < .05) using in vitro fertilization and was unaffected by season (1.5 ± 0.2 and 1.1 ± 0.3 during anovulatory and ovulatory seasons, respectively), in contrast to in vivo embryo production which was affected by season (0.1 ± 0.01 and 0.7 ± 0.2 during anovulatory and ovulatory seasons, respectively). Results demonstrate that transferable embryos can be produced throughout the year in wood bison by both in vivo and in vitro techniques, but the efficiency of embryo production of in vivo-derived embryos is significantly lower during the anovulatory season. 相似文献