The localization and expression of epidermal growth factor and epidermal growth factor receptor in bovine ovary during oestrous cycle

Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.     

表皮生长因子在动物肠道无机离子及其他营养物质吸收中的作用

表皮生长因子(epidermal growth factor,EGF)是生长因子家族成员之一,具有促进细胞生长、细胞迁移、细胞增殖、伤口愈合、骨骼愈合以及营养物质转运等生物学功能。大量研究表明EGF对钠离子、氯离子、镁离子、无机磷、葡萄糖、谷氨酰胺、小肽、5-羟色胺等物质的转运具有促进作用。本文旨在概述EGF对营养物质转运的影响,为EGF在动物生产上的应用提供参考。     

生长因子和体细胞共培养对牛体外受精的影响

为研究表皮生长因子（EGF）和胰岛素（Insulin）对牛卵母细胞体外发育的影响以及体细胞共培养对体外受精胚胎体外发育的影响，将获取的牛卵泡卵母细胞在含有30μg，LEGF或50mg／L Insulin或30μg／LEGF＋50mg／L Insulin的成熟培养液中进行成熟培养，比较不同生长因子对牛卵母细胞体外成熟和体外受精的影响；将受精卵用颗粒细胞单层培养系统或牛输卵管上皮细胞单层培养系统进行体外培养，比较体细胞共培养系统对体外受精胚胎体外发育的影响。结果表明，成熟培养液中添加30μg／LEGF或者30μg／LEGF＋50mg／L Insulin可以显著提高卵母细胞的成熟率和受精后的卵裂率（P〈0．05）；输卵管上皮细胞共培养系统可以显著提高受精后的囊胚发育率（P〈0．05），可以用于牛体外受精胚胎的体外培养。     

猪表皮生长因子基因的遗传变异及其与产仔性状的相关性分析

本研究通过建立两次PCR扩增分型法,分析猪表皮生长因子(epidermal growth factor,EGF)基因第3内含子上的875bp插入片段在13个中外不同繁殖性能的猪种中的遗传变异,以及EGF基因在白色杜洛克×二花脸资源家系180头F2母猪中与繁殖性状的相关性。结果表明,不同类型中国地方猪种与西方商业猪种在EGF基因位点上存在偏态分布。在资源家系中该位点对总产仔数、产活仔数和断奶活仔数无显著影响(P0.05);尽管BB基因型的产活仔数和断奶活仔数分别比AA型多1.74和0.46头,但BB型的个体太少,各基因型间的均值差异不显著(P0.05);虽然产活仔数的a值和d值分别达到0.87和1.24头,但该基因位点的加性效应和显性效应并不明显。因此,需要利用更多的SNP位点和更多样本进一步了解EGF基因与繁殖性状的关联性。     

IGF-1和EGF对辽宁绒山羊初级毛囊体外培养的影响

为研究不同剂量的IGF-1和EGF对辽宁绒山羊毛囊体外生长及毛囊形态的影响,采用显微分离法分离绒山羊初级毛囊,分别测定不同浓度IGF-1(0.1,1,10,100ng·mL-1)、不同浓度EGF(0.2,2,20,100ng·mL-1)和联合添加IGF-1与EGF(分别添加10ng·mL-1和20ng·mL-1)对毛囊形态变化及生长长度的影响.结果表明:IGF-1刺激毛乳头和毛母质细胞分裂增殖;EGF促进毛囊外根鞘细胞分化;联合添加刺激毛球部增大.IGF-1和EGF对毛囊体外生长均具有正向调节作用,作用大小与剂量有关,最适宜浓度IGF-1为10ng·mL-1,EGF为20ng·mL-1,10d后生长长度分别达1.075mm和1.117mm;IGF-1(10ng·mL-1)和EGF(20ng·mL-1)联合添加对毛囊生长促进作用优于单独添加,10d后生长长度达1.413mm.     

细胞分裂间期和分裂期ERK活性研究

[目的]研究分裂间期和分裂期细胞外信号调节蛋白激酶(ERK)活性,以期了解细胞的生理活动.[方法]培养COS7、Hela-H2B和Cho-EGFR细胞,用有或无诺考达唑(Nocodazole)处理后获得分裂期和分裂间期细胞;再用表皮生长因子(EGF)或AG1478处理,分别收集分裂期和分裂间期细胞,裂解后制备蛋白样品,...     

Epidermal growth factor receptor-protein kinase interactions in hepatic membranes of rainbow trout (Oncorhynchus mykiss)

The association between the presence of EGF binding and its associated tyrosine kinase activity was investigated in the hepatic membranes of rainbow trout (Oncorhynchus mykiss). Time course experiments indicted that the binding of EGF to hepatic membranes was temperature dependent and resulted in increased phosphorylation of membrane components. The phosphorylation reaction was dependent on the presence of divalent ions (Mg²⁺ and Mn²⁺) but not monovalent ions (Na⁺ and K⁺) or calcium. Western blot analysis of phosphorylated trout membranes indicated protein bands at 150 and 180 kDa which is similar to that observed in mammals. Use of specific substrates and protein kinase inhibitors also indicated that the increase in EGF stimulated phosphorylation was related to an increase in tyrosine kinase activity. These data support the hypothesis that trout have an EGF-like receptor that has binding and biological activities similar to that observed in mammalian species.     

EGF在哺乳动物卵母细胞体外受精中的作用

[目的]为卵母细胞的生长发育创造更加适宜的环境。[方法]对EGF的理化特性、作用机理及其在卵母细胞体外培养、体外受精和早期胚胎发育中的作用进行阐述。[结果]EGF、IGF和TGF等生长因子在哺乳动物卵母细胞体外培养中起很重要的作用,尤其是在无血清培养条件下。生长因子可大大提高卵母细胞的成熟率和受精率,并对受精卵的发育有很大的促进作用。在众多生长因子中研究的最多的就是EGF。EGF能够促进卵母细胞减数分裂、卵丘细胞扩散,调节卵母细胞胞质成熟。[结论]对EGF的深入研究对于提高哺乳动物卵子的体外成熟率、体外受精率以及胎儿的发育都具有重大意义,为体外受精等技术和胚胎工程的发展提高可靠的保障。但对清楚了解EGF及其受体的性质和作用机制仍存在很多问题,且对表皮生长因子对体外受精的作用研究较少。