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1.
IFN-τ与妊娠   总被引:2,自引:0,他引:2  
IFN-τ属于一类功能特化的 IFN,它是反刍动物母体妊娠识别的孕体信号 ,在黄体维持和妊娠建立过程中发挥重要的生物学功能。本文对 IFN- τ的抗溶黄作用及其抗溶黄机制等方面的研究进展进行了系统综述。  相似文献   

2.
干扰素——τ及其在母体妊娠识别中的作用   总被引:3,自引:0,他引:3  
对于妊娠期比排卵周期长的动物而言,要建立妊娠,就必须阻滞黄体的正常周期性退化,保证孕酮的持续产生,从而维持子宫内膜功能,保证胚胎的发育、着床、胎盘形成及胎儿的成功发育。这种黄体维持现象由Short(1969)首次证明,称为母体妊娠识别(maternalpregnancyrecognition,MPR)。不同物种在母体妊娠识别过程中抑制黄体溶解的方式各异。猪胚泡分泌的雌激素是黄体溶解信号,马的妊娠识别信号及其作用机制还所知不多,可能由胚体分泌一种低分子量蛋白作为信号。而在反刍动物(以绵羊、山羊、牛为代表)中,妊娠识别…  相似文献   

3.
干扰素tau(IFN-τ)是反刍动物特有的一种新型Ⅰ型干扰素,通常被认为是反刍动物的妊娠识别信号,在胚胎与子宫内膜的相互作用中调节一系列相关基因的表达。近年来,随着对IFN-τ研究的深入开展,发现其除了参与调节反刍动物妊娠着床外,在其他物种中还具有抗炎、抗病毒、抗肿瘤、免疫调节等多种生理功能。基于此,文章围绕IFN-τ的主要生理作用展开综述。  相似文献   

4.
干扰素 -τ是由反刍动物孕体附植时发出的特有妊娠信号 ,是建立母体妊娠识别的一种主要因子。反刍动物早期妊娠识别和妊娠诊断是影响其繁殖力的关键因素。文章对干扰素 -τ的分子结构、生物学功能及其在妊娠识别中的作用机理的最新研究作了扼要综述  相似文献   

5.
干扰素-τ是羊孕体附植时发出的特有的妊娠识别信号,它是建立母体妊娠识别的一种主要因子。本文阐述了IFN-τ的分子结构及其最新的研究进展,即IFN-τ和PGF2α、U-CRP、OTR、GM-CSF的互作机理。  相似文献   

6.
干扰素-τ对绵羊妊娠识别影响的研究进展   总被引:1,自引:0,他引:1  
干扰素-τ是羊孕体附植时发出的特有的妊娠识别信号,它是建立母体妊娠识别的一种主要因子。本文阐述了IFN—τ的分子结构及其最新的研究进展,即IFN—τ和PGF2α、U—CRP、OTR、GM—CSF的互作机理。  相似文献   

7.
胚胎附植是哺乳动物生殖过程中的关键步骤。干扰素-τ是反刍动物特有的妊娠识别信号,在妊娠早期特异表达并发挥重要作用。本文综述了干扰素-τ在反刍动物胚胎附植及胎盘形成早期发挥的作用,总结该阶段受干扰素-τ调控的相关基因,以及干扰素-τ与孕酮、前列腺素、皮质醇在影响子宫内环境中的相互作用,为深入研究反刍动物胚胎附植相关基因和进一步了解其胚胎附植机制提供理论基础。  相似文献   

8.
干扰素-τ(INF-τ)最初被称为滋养层蛋白-1(TP-1),是反刍动物滋养层细胞分泌的一类低分子质量酸性蛋白质,分子质量一般为17~24 ku。干扰素-τ具有Ⅰ型干扰素的共同特性,即抗病毒、抗细胞增生、免疫调节等[1]。但IFN-τ在生物学功能方面有其自身特点,它仅在胚胎滋养层细胞中表达,无需病毒诱导;另外,高浓度IFN-τ与其他Ⅰ型干扰素  相似文献   

9.
羊干扰素可分为Ⅰ型、Ⅱ型,后者与其他动物干扰素一样,只包含一种干扰素即IFN-γ,而前者被确定的却只有IFN—ω和IFN—τ。对具有强抗病毒能力的干扰素α的研究一直是干扰素研究的主攻方向,但笔者却没有查到羊干扰素α的相关资料(80年代末曾被定义为IFN—αⅡ的基因现已被确定为IFN—  相似文献   

10.
干扰素-τ及其在反刍动物中抗黄体溶解作用   总被引:1,自引:1,他引:0  
干扰素-τ是一个在反刍动物妊娠建立过程中起着关键性作用的细胞因子,属于Ⅰ型干扰素家族。在围植入期由胚胎滋养层单核细胞合成分泌,主要作用于子宫内膜,抑制溶黄体素PGF2α的合成分泌,起到抗黄体溶解作用,保证妊娠的建立。导致牛胚胎早期死亡的一个重要原因是抗黄体溶解机制失调,因此干扰素-τ被认为是一个能有效提高妊娠率的可操控靶细胞因子。  相似文献   

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13.
Maternal recognition of pregnancy refers to the requirement for the conceptus (embryo and its associated extra-embryonic membranes) to produce a hormone that acts on the uterus and/or corpus luteum (CL) to ensure maintenance of a functional CL for production of progesterone; the hormone required for pregnancy in most mammals. The pregnancy recognition signal in primates is chorionic gonadotrophin which acts directly on the CL via luteinizing hormone receptors to ensure maintenance of functional CL during pregnancy. In ruminants, interferon tau (IFNT) is the pregnancy recognition signal. IFNT is secreted during the peri-implantation period of pregnancy and acts on uterine epithelia to silence expression of estrogen receptor alpha and oxytocin receptor which abrogates the oxytocin-dependent release of luteolytic pulses of prostaglandin F2-alpha (PGF) by uterine epithelia; therefore, the CL continues to produce progesterone required for pregnancy. Pig conceptuses secrete interferon delta and interferon gamma during the peri-implantation period of pregnancy, but there is no evidence that they are involved in pregnancy recognition signaling. Rather, pig conceptuses secrete abundant amounts of estrogens between Days 11 to 15 of pregnancy required for maternal recognition of pregnancy. Estrogen, likely in concert with prolactin, prevents secretion of PGF into the uterine venous drainage (endocrine secretion), but maintains secretion of PGF into the uterine lumen (exocrine secretion) where it is metabolized to a form that is not luteolytic. Since PGF is sequestered within the uterine lumen and unavailable to induce luteolysis, functional CL are maintained for production of progesterone. In addition to effects of chorionic gonadotrophin, IFNT and estrogens to signal pregnancy recognition, these hormones act on uterine epithelia to enhance expression of genes critical for growth and development of the conceptus.  相似文献   

14.
15.
In 1977 Bazer and Thatcher proposed that maternal recognition of pregnancy in the pig involves the secretion of PGF(2alpha) towards the uterine lumen (exocrine) rather than towards the uterine venous drainage (endocrine) as occurs in the non-pregnant pig during the mid to late stages of the estrous cycle. The retrograde transfer of PGF(2alpha) from the venous blood and uterine lymph into the uterus and the ability of the uterine vein and artery wall to accumulate PGF(2alpha) could constitute a part of putative mechanism of corpus luteum protection during early pregnancy. A luteotropic/anti-luteolytic effect of PGE(2) in the pig also has been frequently demonstrated and it seems that the most effective agent in changing PGE(2):PGF(2alpha) secretion is estradiol. The role for oxytocin during luteolysis and early pregnancy is controversial. It appears, however, that the main function of this hormone is autocrine and/or paracrine stimulation of PGF(2alpha) secretion. Pig trophoblastic interferons, unlike those of ruminants, do not themselves exert an anti-luteolytic effect in pigs. It is likely, that cytokines and angiogenic growth factors are involved in the initiation of luteolysis and/or maintenance of corpora lutea (CL).A discovery of functional LH receptors in porcine endometrium opened a new possibility for this hormone in luteolysis and perhaps in recognition of pregnancy in pigs. The endogenous LH pulses can provoke prostaglandin secretion from endometrium in pigs. On the other hand prolongation of up-regulation of LH receptors in endometrium of early pregnant gilts can additionally increase angiogenic factor production before the process of implantation is completed. Finally new integrated concepts of luteolysis and inhibition of luteolysis in pigs based on selectively reviewed information are presented.  相似文献   

16.
Inadequate delivery of nutrients results in intrauterine growth restriction (IUGR), which is a leading cause of neonatal morbidity and mortality in livestock. In ruminants, inadequate nutrition during pregnancy is often prevalent due to frequent utilization of exensive forage based grazing systems, making them highly susceptible to changes in nutrient quality and availability. Delivery of nutrients to the fetus is dependent on a number of critical factors including placental growth and development, utero-placental blood flow, nutrient availability, and placental metabolism and transport capacity. Previous findings from our laboratory and others, highlight essential roles for amino acids and their metabolites in supporting normal fetal growth and development, as well as the critical role for amino acid transporters in nutrient delivery to the fetus. The focus of this review will be on the role of maternal nutrition on placental form and function as a regulator of fetal development in ruminants.  相似文献   

17.
Inadequate delivery of nutrients results in intrauterine growth restriction(IUGR), which is a leading cause of neonatal morbidity and mortality in livestock. In ruminants, inadequate nutrition during pregnancy is often prevalent due to frequent utilization of exensive forage based grazing systems, making them highly susceptible to changes in nutrient quality and availability. Delivery of nutrients to the fetus is dependent on a number of critical factors including placental growth and development, utero-placental blood flow, nutrient availability, and placental metabolism and transport capacity. Previous findings from our laboratory and others, highlight essential roles for amino acids and their metabolites in supporting normal fetal growth and development, as well as the critical role for amino acid transporters in nutrient delivery to the fetus. The focus of this review will be on the role of maternal nutrition on placental form and function as a regulator of fetal development in ruminants.  相似文献   

18.
Embryonic mortality is found to be the main source of reproductive wastage in domestic ruminants. Many genes are involved in the growth and development of the embryo, and the interferon‐stimulated gene 15 (ISG 15) is one of the major gene stimulated by interferon tau, the maternal recognition of pregnancy signal in ruminants. In this study, both genomic and cDNA sequences of ISG 15 from Bos indicus (Deoni breed) were amplified and characterized. The genomic sequence of Deoni ISG 15 exhibited 99% identity with Bos taurus and 97% identity with that of Bos mutus and Bubalus bubalis. Moreover qRT‐PCR analysis revealed constitutive expression of the ISG 15 mRNA in peripheral blood mononuclear cells of Deoni heifers and multiparous cows during early pregnancy. Fourteen Deoni heifers and fifteen multiparous Deoni cows were synchronized for timed AI by CIDR‐Ovsynch protocol, and six animals were kept as cyclic control in each group. Blood samples were collected on days 7, 14, 16, 18, 21, 30 and 45 from the day of AI. Pregnancy was confirmed by plasma progesterone level through ELISA. A significantly higher expression of ISG 15 mRNA was found on day 16 (< .05) and day 18 (< .05) of pregnancy in nulliparous heifers. Although in multiparous Deoni cows ISG 15 expression was greater in pregnant cows, difference was statistically non‐significant. The result of this study indicates that ISG 15 gene expression is upregulated during 16–18 days of pregnancy and could be used as an early pregnancy marker in dairy cows especially in heifers.  相似文献   

19.
Precolostral calves and their dams were serologically investigated for the presence of antibodies against Bovine Herpesvirus 1 in diagnostic tests with a very high sensitivity and specificity. Although the syndesmo-chorial type of placenta of ruminants does not transfer gamma globulins, a large number of calves had antibodies, in most cases in a very low concentration. Significant correlations were found between the serological status of the dam, the status of the calf, and the titre of antibodies. Oral intake of maternal blood by the calf at birth or transmission or leakage of maternal antibodies during pregnancy might be possible causes of precolostrally positive calves. From the results it is concluded that to reduce the risk of obtaining BHV1-positive calves, BHV1-negative dams should be selected for breeding purposes.  相似文献   

20.
孕酮的内分泌调节与免疫功能对动物早期妊娠建立和维持十分重要。目前,在反刍动物生产中,胚胎丢失、早期流产等问题一直困扰着养殖户,而孕酮引起的免疫耐受机制还不很清楚。作者通过介绍孕酮的来源及作用方式、孕酮与机体免疫、孕酮介导妊娠免疫耐受等内容,阐述了孕酮在反刍动物早期妊娠中的免疫耐受作用,为孕酮在妊娠免疫耐受方面的研究提供理论参考。  相似文献   

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