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哺乳动物早期胚胎滋养外胚层发育的研究进展 总被引:1,自引:1,他引:0
囊胚形成过程中,胚胎卵裂球分化为滋养外胚层和内细胞团细胞。囊胚孵出后,滋养外胚层又分化为极滋养层和壁滋养层。滋养外胚层的分化对哺乳动物早期胚胎发育至关重要。研究表明,影响滋养外胚层发育的关键基因主要为Tead4、Cdx2和Eomes,敲除或突变这些基因将导致滋养外胚层细胞分化错误,而滋养外胚层的完整性、渗透性和液体转运功能受损也将导致囊胚形成失败。本文主要综述了哺乳动物滋养外胚层的发育、滋养外胚层发育需要的关键基因、调控滋养外胚层完整性和功能相关的蛋白,以及这些蛋白与滋养外胚层发育关键基因之间可能存在的关系,为进一步研究哺乳动物早期胚胎滋养外胚层的调控机制提供参考。 相似文献
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利用微流控芯片模拟输卵管微环境,探讨物理性刺激对早期胚胎发育的影响,为解决早期胚胎体外囊胚发育率较低、胚胎质量差的问题提供帮助。本实验采用一次铸造成型制备微流控芯片培养装置,并应用培养装置对小鼠1-细胞期胚胎进行培养,观察胚胎体外发育率。结果表明,利用微流控芯片培养组与对照组2相比,2-细胞胚胎发育率差异不显著(P0.05),但是,在8-细胞胚胎发育率、桑葚胚发育率和囊胚发育率都差异显著(P0.05)。此外,囊胚内总细胞数显著提高(P0.05)。结论:一次铸造成型微流控芯片制作方法简便易行且培养液不易外漏,这种培养装置能显著提高小鼠早期胚胎体外囊胚发育率和胚胎的质量。 相似文献
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哺乳动物胚胎的活性氧来源及其抗氧化机制 总被引:2,自引:2,他引:0
活性氧(reactive oxygen species, ROS)与胚胎发育缺陷密切相关,胚胎或其培养的环境都有可能产生ROS,一些外源因子能够使胚胎的ROS产量增加,引起胚胎发育阻滞,这严重地限制了与胚胎相关的研究。胚胎存在着多种抗氧化机制,在实际操作中应结合胚胎发育各时期内部ROS的来源及其抗氧化机制,提高细胞内部抗氧化效率;控制培养条件,完善培养体系,降低外在因素对ROS的诱发作用,更高效地生产体外发育胚胎。 相似文献
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为了探究YWHAZ蛋白在小鼠早期胚胎发育过程中的表达、定位和作用,本试验利用RT-PCR和Western blot方法检测Ywhaz基因及其编码蛋白在小鼠早期胚胎发育中的表达;利用免疫荧光技术检测YWHAZ蛋白在小鼠早期胚胎发育过程中的定位;使用特异性的siRNA沉默合子中的Ywhaz,在胚胎发育的1.5,2.5,3.0,3.5,4.5,5.0 dpc分别观察2-细胞、4-细胞、8-细胞、桑葚胚和囊胚的发育率,阐明在合子中沉默Ywhaz基因对小鼠早期胚胎发育的影响。结果显示,Ywhaz mRNA及其编码蛋白在小鼠1-细胞、2-细胞、4-细胞、8-细胞、桑葚胚和囊胚中均有表达,YWHAZ蛋白定位在小鼠早期胚胎的细胞质和细胞核中。Ywhaz沉默组的2-细胞、4-细胞、8-细胞、桑葚胚和囊胚的发育率均极显著低于对照组(P<0.01),沉默组5.0 dpc囊胚率显著高于其4.5 dpc囊胚率(P<0.05)。结果表明,Ywhaz mRNA及其编码的蛋白在小鼠早期胚胎中有表达,其蛋白主要定位在早期胚胎的细胞核和细胞质中;在合子中沉默Ywhaz基因可导致小鼠早期胚胎发育率降低且存在明显... 相似文献
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本研究旨在探讨PGI2类似物iloprost对猪胚胎体外发育的影响。试验以IVF胚胎为研究对象,分别在不同时期(0、24、48、72h)将不同浓度(0、0.2、0.5、1.0、2.0、5.0、10.0μmol.L-1)iloprost加入到猪胚胎培养液中,于156h时记录囊胚发育率和囊胚细胞数,筛选获得最佳添加方案,检测胚胎脂肪代谢速度和代谢相关基因(cox2、creb、pparδ、pdk、cpt2)的表达水平,分析iloprost影响胚胎发育的机制。结果显示,最佳的添加方案为,在受精后48h加入2.0μmol.L-1 iloprost,胚胎囊胚发育率(28%)和囊胚细胞数(49.42)显著高于(P<0.05)对照组的囊胚发育率(16%)和囊胚细胞数(28.22);添加iloprost后,胚胎脂肪酸降解速度也显著加快(P<0.05),脂肪酸代谢相关基因cox2、creb、pparδ、cpt2的表达量上升,糖代谢相关基因pdk表达量无显著变化。结果表明,PGI2类似物iloprost可以促进胚胎降解脂肪酸,为胚胎发育提供能量,提高了胚胎体外发育能力。 相似文献
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《动物医学进展》2021,42(8)
为探索哺乳动物孤雌激活胚胎早期发育过程中胞吞作用相关蛋白的动态表达,通过体外生产小鼠孤雌激活胚胎,采用实时荧光定量PCR(RT-qPCR)和蛋白质免疫印迹(Western blot)技术检测不同发育时期小鼠孤雌激活胚胎胞吞作用相关蛋白Cav1、Cav2基因和蛋白相对表达水平,并采用免疫荧光技术进行不同发育时期小鼠孤雌激活胚胎中Cav1、Cav2表达定位分析。结果表明,在小鼠孤雌激活胚胎不同时期均可检测到Cav1、Cav2基因及其蛋白的表达,其中囊胚和桑椹胚中该2个基因的表达水平最高,4-8细胞时期次之,2细胞最低;各发育时期孤雌激活胚胎中Cav1、Cav2蛋白主要定位在胚胎细胞胞质内;囊胚中内细胞团(ICM)细胞中Cav1的荧光强度高于滋养层细胞。说明胞吞作用相关蛋白Cav1、Cav2可能参与小鼠早期胚胎发育的生理调控,桑椹胚和囊胚时期可能是其发挥生理功能的重要时期,并且在囊胚时期对内细胞团发育的调控作用更为显著。研究结果可为探索胞吞作用参与哺乳动物胚胎早期发育的调控机制提供重要参考。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献