《生命科学》 2017, 29(10): 1016-1024
摘 要：摘 要：在哺乳动物胚胎发育过程中，中内胚层(mesendoderm) 也被称为原条(primitive streak)，是中胚层和内胚层分化的过渡时期。中内胚层的存在时间较短，但成功的中内胚层分化对随后进行的中胚层与内胚层发育至关重要。发育生物学的研究极大地推动了人们对胚胎发育的认识，同时，越来越多体外分化系统的建立也加深了对环境信号如何影响胚层分化的理解。近些年来，通过表观遗传的研究，人们逐渐认识到染色体结构与组蛋白修饰的改变也在分化发育过程中起到重要作用。通过胚胎干细胞定向诱导中内胚层分化来探究相关分子机制，不仅有助于对早期胚胎发育的了解，也有助于临床应用与疾病治疗。现总结了TGF-β 信号、Wnt 信号和FGF 信号调控中内胚层分化的研究现状，并概述了这些信号如何与表观修饰共同调控胚胎干细胞向中内胚层分化的进展。
Abstract: Abstract: During early development of mammalian embryos， there exists an intermediate state， called primitive streak， also known as mesendoderm (ME)， from which mesoderm and endoderm are derived. Although it is a transient stage during embryogenesis， successful differentiation of ME is critical for the following formation of mesoderm and endoderm. Developmental biology studies have greatly advanced our knowledge on embryogenesis， while in vitro chemical defined differentiation systems facilitate dissection of the influence of extracellular signals on germ layer formation. In addition， epigenetic regulations such as chromatin structure changes and histone modification alterations are appreciated to play critical roles in the process of cell differentiation and embryo development. In this review， we summarize recent progress on how extracellular signals (TGF-β， Wnt， FGF) are integrated with intracellular epigenetic modifications during ME differentiation.
