Department of Biology, Developmental Biology, University of Erlangen-Nuremberg, Erlangen, Germany.
Department of Ecology, Evolution and Behavior, Hebrew University of Jerusalem, Jerusalem, Israel.
Elife. 2019 Mar 21;8:e39748. doi: 10.7554/eLife.39748.
Small open reading frames (smORFs) encoding 'micropeptides' exhibit remarkable evolutionary complexity. Conserved peptides encoded by are essential for embryo segmentation in but, in , function in terminal epidermal differentiation and patterning of adult legs. Here, we show that a molecular complex identified in epidermal differentiation, comprising Mlpt peptides, ubiquitin-ligase Ubr3 and transcription factor Shavenbaby (Svb), represents an ancient developmental module required for early insect embryo patterning. We find that loss of segmentation function for this module in flies evolved concomitantly with restriction of Svb expression in early embryos. Consistent with this observation, artificially restoring early Svb expression in flies causes segmentation defects that depend on function, demonstrating enduring potency of an ancestral developmental switch despite evolving embryonic patterning modes. These results highlight the evolutionary plasticity of conserved molecular complexes under the constraints of essential genetic networks.
This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
小开放阅读框（smORFs）编码“微肽”表现出显著的进化复杂性。由 编码的保守肽对于 中的胚胎分割是必不可少的，但在 中，它们在终末表皮分化和成年腿的模式形成中起作用。在这里，我们表明，在 表皮分化中鉴定的一个分子复合物，包括 Mlpt 肽、泛素连接酶 Ubr3 和转录因子 Shavenbaby（Svb），代表了一个古老的发育模块，该模块对于早期昆虫胚胎模式形成是必需的。我们发现，该模块的分段功能丧失在苍蝇中进化的同时，Svb 表达在早期 胚胎中受到限制。与这一观察结果一致，人工恢复苍蝇中早期 Svb 的表达会导致依赖 功能的分段缺陷，这表明尽管胚胎模式形成模式在进化，但古老的发育开关仍然具有持久的潜力。这些结果突出了在必需遗传网络的限制下保守分子复合物的进化可塑性。
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