团花树α扩展蛋白基因的克隆及表达分析

采用扩增保守区域、基因组步移及3’RACE技术,在团花树中克隆到15个α-expansin基因的cDNA序列,命名为AcEXPA2-16(GenBank注册号JF922686-JF922700),其相对应的基因组序列GenBank注册号为JF922701-JF922715。包括已知的AcEXPA1,这16个EXPA蛋白的大小及序列高度保守,包括N端的信号肽、3个外显子和2个内含子。通过氨基酸序列比对和系统进化树分析,AcEXPA1-16分为4个亚族,分别为A、B、C和D亚族。定量PCR分析显示AcEXPA1-16基因在同一组织中的表达存在冗余现象,而单个基因在不同的组织中又存在特异表达,尤其AcEXPA8在形成层中的表达水平极高。这表明AcEXPA8在木质部发生的过程中可能起到重要的作用。研究结果为在团花树中研究α-expansin基因与木质部的生长和材质的关系提供信息,并最终为林木分子育种提供潜在的候选基因。

Transforming growth factor-α promotes mouse blastocyst outgrowth and secretion of matrix metalloproteinases

Objective To study the effect of transforming growth factor-α (TGF-α) on early stage of embryo implantation.Methods Mouse blastocysts were cultured in vitro in medium containing various concentrations of TGF-α. Blastocyst implantation capacity was evaluated by calculating the percentage of embryos with attachment or outgrowth. Matrix metalloproteinases (MMPs) secretion of blastocysts was observed using gelatin zymography. Results There was no significant difference in the percentage of attachment between control and TGF-α treated groups, but the percentage of outgrowth of TGF-α treated groups was significantly higher than that of the control group after 24h culturing. Gelatin zymography showed that blastocysts cultured in TGF-α treated groups started secreting MMPs earlier than those in the control group.Conclusion TGF-α is involved in regulating the mouse embryo implantation process by promoting blastocyst outgrowth and secreting matrix matalloproteinases.