在牛中,状芽细胞体的排列决定了胚胎左右不对称的途径
Reiko Kuroda1, Bunshiro Endo, Masanori Abe
1Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan. ckuroda@mail.ecc.u-tokyo.ac.jp
Nature
|November 27, 2009
概括
牛的早期发育表明,细胞在八细胞阶段的排列决定了左右不对称. 操纵这种性胚芽细胞组合可以逆转胚胎的手性和节点信号.
科学领域:
- 发展生物学 发展生物学
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 左右不对称是大多数动物的基本特征,但其早期的发育机制仍然不太了解.
- 像Lymnaea stagnalis这样的胃类动物表现出由母性因素决定的遗传性性 (左侧/右侧),其潜在的基因和机制尚未确定.
研究的目的:
- 为了确定关键的发育阶段和决定Lymnaea stagnalis.右左不对称的细胞事件.
- 研究早期胚胎性和下游信号通路,特别是节点通路之间的关系.
主要方法:
- 在Lymnaea stagnalis胚胎的第三个裂变 (四到八细胞阶段) 中,在胚胎布质体排列的机械微处理.
- 观察胚胎手性和随后的操纵牛的发展.
- 对操纵胚胎中的节点信号通路表达模式的分析.
- 使用逆向交叉的先天性动物进行遗传联系分析.
主要成果:
- 在八细胞阶段,而不是更早的阶段,布拉斯托默的奇拉排列决定了左右不对称.
- 微操作第三切割性拉性逆转了胚胎的手性,产生了具有逆转拉性可行的牛.
- 操纵改变了胚胎的节点表达模式,这表明布拉斯托马的排列在这个途径上游起作用.
- 强烈的遗传联系被发现在 handedness-determining 基因和手性细胞骨动力学在第三裂变之间.
结论:
- 在八细胞阶段由母体决定的胚芽细胞的排列对于决定胚胎信号通路和生物体的左右图案 (奇罗摩生) 是至关重要的.
- 这些发现确立了早期细胞性和建立不对称性的节点途径之间的机械联系.
- 在其他有机体 (包括脊椎动物) 的左右图案中,可能保留了类似的状母细胞体配置机制.
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