Dorsoventral pattern formation

在果蝇中，当来自种系下体细胞的局部EGF信号在蛋壳中提供空间线索时，背腹侧（DV）轴的形成开始于卵发生过程，这在胚胎发生过程中导致TO11/NF-KB信号级联的腹侧激活。Toll信号诱导中胚层形成，并建立了Dpp （BMP）信号梯度，该梯度影响胚胎和胚胎外胚层。使用候选基因方法，我们能够分析Tribolium中DV轴形成的关键方面，但我们未能揭示导致种系信号定位的过程，腹侧蛋壳线索的形成，Toll配体的激活以及导致中胚层规范的网络。显然，在一个很大程度上保守的发育网络中，新的组成部分在多个点上被招募。此外，两个过程在果蝇中缺乏发育对应体：生长区的DV模式和胚胎外发育。在iBeetle项目中，我们计划确定DV模式网络的缺失成分，并确定生长区DV模式和胚胎外发育所需的基因。

In Drosophila, dorsoventral (DV) axis formation begins during oogenesis when localized EGF signaling from germline lo soma provides spatial cues in the eggshell, which during embryogenesis lead lo ventral activation of the TO11/NF-KB signaling cascade. Toll signaling induces mesoderm formation and establishes a gradient of Dpp (BMP) signaling that patterns the embryonic and extraembryonic ectoderm. Using a candidate-gene approach we were able lo analyze key aspects of DV axis formation in Tribolium, but we failed lo unravel the processes leading to the localization of the germline signal, the formation of the ventral eggshell cues, the activation of the Toll ligand and the network leading lo mesoderm specification. Apparently, new components have been recruited at multiple points within a largely conserved developmental network. Furthermore, two processes lack developmental counterparts in Drosophila: DV patterning in the growth zone and extraembryonic development. Within the iBeetle project we plan lo identify missing components of the DV patterning network and identify genes required for DV patterning in the growth zone and for extraembryonic development.