Xu X, Zhang Z, Yang Y, Huang S, Li K, He L, Zhou X
School of Life Science, East China Normal University, Shanghai, China.
Agricultural and Medical Biotechnology, University of Kentucky, Lexington, KY, USA.
Insect Mol Biol. 2018 Dec;27(6):675-685. doi: 10.1111/imb.12502. Epub 2018 Aug 17.
As a transcriptional coactivator, Yorkie (Yki) is a major downstream target of the Hippo signalling pathway to regulate the organ size during animal development and regeneration. Previous microarray analysis in the silkworm, Bombyx mori, has shown that genes associated with the Hippo pathway were primarily expressed in gonads and imaginal discs. The RNA-interference-mediated silencing of Yki at the early wandering stage delayed B. mori development and ovary maturation, whereas baculovirus-mediated overexpression at the late larval instar facilitated organ growth and accelerated metamorphosis. Here, we employed CRISPR/Cas9-mediated mutagenesis to investigate the function of Yki in B. mori (BmYki) at the embryonic and early larval stages. Knocking out of BmYki led to reduced body size, moulting defects and, eventually, larval lethality. Sequence analysis of CRISPR/Cas9 mutants exhibited an array of deletions in BmYki. As a critical downstream effector of the Hippo kinase cassette, silencing of BmYki at the embryonic stage is indispensable and the consequence is lethal. Given that the Hippo signalling pathway is evolutionarily conserved, Yki has the potential to be a novel molecular target for genetic-based pest management practices.
作为一种转录共激活因子，Yorkie（Yki）是Hippo信号通路的主要下游靶点，在动物发育和再生过程中调节器官大小。先前对家蚕的微阵列分析表明，与Hippo通路相关的基因主要在性腺和成虫盘中表达。在早期徘徊阶段通过RNA干扰介导的Yki沉默会延迟家蚕的发育和卵巢成熟，而在幼虫后期通过杆状病毒介导的过表达则促进器官生长并加速变态。在这里，我们采用CRISPR/Cas9介导的诱变技术来研究Yki在家蚕胚胎期和幼虫早期（BmYki）的功能。敲除BmYki会导致体型减小、蜕皮缺陷，并最终导致幼虫死亡。对CRISPR/Cas9突变体的序列分析显示BmYki存在一系列缺失。作为Hippo激酶盒的关键下游效应因子，在胚胎期沉默BmYki是必不可少的，其结果是致命的。鉴于Hippo信号通路在进化上是保守的，Yki有可能成为基于基因的害虫管理实践的新分子靶点。
