Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany.
Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstrasse 5, Erlangen, 91058, Germany.
Dev Biol. 2020 Apr 1;460(1):20-31. doi: 10.1016/j.ydbio.2019.04.015. Epub 2019 May 7.
Recently, it was shown that anterior-posterior patterning genes in the red flour beetle Tribolium castaneum are expressed sequentially in waves. However, in the fruit fly Drosophila melanogaster, an insect with a derived mode of embryogenesis compared to Tribolium, anterior-posterior patterning genes quickly and simultaneously arise as mature gene expression domains that, afterwards, undergo slight posterior-to-anterior shifts. This raises the question of how a fast and simultaneous mode of patterning, like that of Drosophila, could have evolved from a rather slow sequential mode of patterning, like that of Tribolium. In this paper, we propose a mechanism for this evolutionary transition based on a switch from a uniform to a gradient-mediated initialization of the gap gene cascade by maternal Hb. The model is supported by computational analyses and experiments.
最近，已经表明在红粉甲虫 Tribolium castaneum 中，前后模式基因以波的形式依次表达。然而，在果蝇 Drosophila melanogaster 中，与 Tribolium 相比，这种昆虫具有衍生的胚胎发生模式，前后模式基因迅速且同时出现，成为成熟的基因表达域，随后经历轻微的后至前移位。这就提出了一个问题，即像 Drosophila 那样快速且同时的模式化如何从 Tribolium 那样相对缓慢的顺序模式化中进化而来。在本文中，我们提出了一种基于母体 Hb 从均匀初始化到梯度介导的间隙基因级联初始化的转变的机制，该机制为这一进化转变提供了理论依据。该模型得到了计算分析和实验的支持。
