极性蛋白Scrib在原肠胚发生中作用研究

发布时间：2018-03-29 14:16

本文选题：Scrib　切入点：numb　出处：《广东药学院》2011年硕士论文

【摘要】：在胚胎发生过程中,从原肠期开始出现器官的发生和分化,神经管、体节、心脏、脑、原肠、血管等都是在这个阶段产生的,而这一切的开端始于囊胚期上胚层的细胞向中线运动形成原条产生中胚层(也叫EMT)。卵子及随后的发育过程中,在受精卵内众多因子参与到原条的细胞运动及后续器官发育中,而表达在上皮类细胞中的极性蛋白基因是重要的调控一族。果蝇中极性蛋白Scrib的缺失使得果蝇上皮细胞的极性缺失,细胞过度增殖;在人类中Scrib中作为肿瘤抑制基因发挥作用;同时Scrib也在神经发育中对神经突触的功能的维持、内耳的发育也起到重要的作用。在我们前期的研究中在体外已经证实了Scrib可以和Numb结合负调控Notch信号。这条信号通路在体内是否有功能及有何功能,还没有得到证实。本课题以鸡胚作为动物模型研究体内情况下Scrib和Numb的异常表达对胚胎发育产生的影响及如何产生这种影响。我们通过原位杂交的方法分别检测了Scrib、Numb的表达,探索两种基因在原肠期的表达规律,发现Scrib表达开始于HH 4并在原条前端表达,表达集中,当到达HH 7时则呈弥散性表达;Numb的表达在早期和Scrib相同,但后期主要表达在神经系统中。通过电转染的方法分别过表达Scrib和Numb,发现过表达引起胚胎发育异常,过表达早期使得胚胎细胞迁移受阻,上胚层的细胞对中胚层的转变受到抑制;后期过表达引起神经管闭合缓慢,起到延缓发育的作用。我们用shRNA降调Scrib的表达发现了相反的现象,降调后促进神经管的发育。同时也检测与神经管发育有关的基因Pax-7、Islet-1等等,发现Pax-7表达不受影响,但Islet-1表达受到抑制。综上所述,我们的结果发现Numb和Scrib的过表达和降调对EMT的转变和神经管的发育具有相关性,这对于我们进一步探索Scrib和Numb结合信号的功能及下游分子机制打下牢固的基础。结论:Scrib和numb在原肠期鸡胚发育中起到重要作用,过表达Scrib和Numb抑制EMT的转变和神经管的发育;降调Scrib则促进神经管的发育。
[Abstract]:In the process of embryogenesis, organ development and differentiation begin from the proto-intestinal stage. Nerve tubes, ganglia, heart, brain, intestine, blood vessels and so on are produced at this stage. And all this begins when the cells in the ectoderm of the blastocyst move toward the midline to form the mesoderm (also known as EMT.oocyte and subsequent development), in which many factors are involved in the cellular movement of the blastocyst and in the subsequent organ development. The polarity protein gene expressed in epithelioid cells is an important regulatory family. The absence of polar protein Scrib in Drosophila results in the loss of polarity and over-proliferation of the cells in Drosophila melanogaster, and plays an important role as a tumor suppressor gene in human Scrib. Scrib also maintains synaptic function during neurodevelopment. The development of the inner ear also plays an important role. In our previous studies, it has been demonstrated in vitro that Scrib can bind to Numb to negatively regulate the Notch signal. The effect of abnormal expression of Scrib and Numb on embryonic development in vivo was studied by using chicken embryo as animal model. In situ hybridization was used to detect the expression of Scribbun numb. The expression of Scrib began at HH4 and expressed at the front of the original strip. When HH7 reached HH7, the expression of Scrib was diffusely expressed in the same way as Scrib in the early stage. However, in the later stage, the expression of Scrib and numbwas over expressed in the nervous system. It was found that overexpression caused abnormal embryonic development, and early overexpression blocked the migration of embryonic cells. The changes of mesoderm were inhibited by the cells in the ectoderm, and the slow closure of the neural tube caused by the late overexpression, which delayed the development of the neural tube. We found the opposite phenomenon with the down-regulation of Scrib expression in shRNA. At the same time, the gene Pax-7 Islet-1 and so on were detected. It was found that the expression of Pax-7 was not affected, but the expression of Islet-1 was inhibited. In conclusion, our results show that the overexpression and downregulation of Numb and Scrib are related to the transition of EMT and the development of neural tube, which lays a solid foundation for us to further explore the function of Scrib and Numb binding signal and the downstream molecular mechanism. Conclusion the expression of Scrib and Numb inhibits the transformation of EMT and the development of neural tube, and the downregulation of Scrib can promote the development of neural tube. [conclusion] Scrib and numb play an important role in the development of chicken embryo in prointestinal stage, and the overexpression of Scrib and Numb inhibit the development of EMT and neural tube.
【学位授予单位】：广东药学院
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R321

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