Plavskin Yevgeniy, Nagashima Akitomo, Perroud Pierre-François, Hasebe Mitsuyasu, Quatrano Ralph S, Atwal Gurinder S, Timmermans Marja C P
Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
National Institute for Basic Biology, Okazaki 444-8585, Japan; Exploratory Research for Advanced Technology, Japan Science and Technology Agency, Okazaki 444-8585, Japan.
Dev Cell. 2016 Feb 8;36(3):276-89. doi: 10.1016/j.devcel.2016.01.010.
Novel developmental programs often evolve via cooption of existing genetic networks. To understand this process, we explored cooption of the TAS3 tasiRNA pathway in the moss Physcomitrella patens. We find an ancestral function for this repeatedly redeployed pathway in the spatial regulation of a conserved set of Auxin Response Factors. In moss, this results in stochastic patterning of the filamentous protonemal tissue. Through modeling and experimentation, we demonstrate that tasiRNA regulation confers sensitivity and robustness onto the auxin response. Increased auxin sensitivity parallels increased developmental sensitivity to nitrogen, a key environmental signal. We propose that the properties lent to the auxin response network, along with the ability to stochastically modulate development in response to environmental cues, have contributed to repeated cooption of the tasiRNA-ARF module during evolution. The signaling properties of a genetic network, and not just its developmental output, are thus critical to understanding evolution of multicellular forms.
新的发育程序通常通过对现有基因网络的征用而进化。为了理解这一过程，我们探索了小立碗藓中TAS3 tasiRNA途径的征用情况。我们发现这个被反复重新利用的途径在一组保守的生长素响应因子的空间调控中具有祖先功能。在苔藓中，这导致丝状原丝体组织的随机模式形成。通过建模和实验，我们证明tasiRNA调控赋予了生长素响应敏感性和稳健性。生长素敏感性的增加与对氮（一种关键环境信号）的发育敏感性增加平行。我们提出，赋予生长素响应网络的特性，以及响应环境线索随机调节发育的能力，在进化过程中促成了tasiRNA-ARF模块的反复征用。因此，基因网络的信号特性，而不仅仅是其发育输出，对于理解多细胞形式的进化至关重要。
