飞蝗型变可塑性的父性遗传及其表观遗传机制研究

One of the current hot topics for worldwide researchers has been the transgenerational inheritance of environmental information. As such environmental cues experienced by either parent could be transmitted to their offspring, resulting into phenotypic changes in offspring to match the ancestral environments. The transgenerational effect has for-reaching implications on species survival and evolution. However, the majority of examples of transgenerational effects described have been with maternal effect, and only a handful of examples of paternal effect were documented in animals. This unconventional mode of information transfer involves epigenetic mechanisms by which transgenerational modification of the genome occurs without a corresponding change in DNA sequence. However, it is less known about the regulatory mechanism, particularly the epigenetic mechanism underlying the transgenerational inheritance. Inheritance of phase plasticity in the migratory locust provides a good model for the study of transgenerational effect in animal. After strictly controlled for the effects of genetic background and genetic variation, we'll study in this project: (1) the phase characteristics that are inherited by paternal effect induced by population density; (2) the inheritance of expression of functionally important genes and noncoding RNAs; (3) the regulatory role of DNA methylation in the control of key gene expression. Our study will have important implications for the molecular mechanism underpinning transgenerational inheritance and will facilitate our understanding of the development of locust outbreak in nature.

目前一个非常活跃的研究领域是环境信息的跨代遗传；许多物种能够将亲代经历的环境信息传递给子代，子代表现出相应的表型改变，来适应与亲代类似的环境。环境信息的跨代传递对物种的生存和进化具有深远的意义。但过去关于动物的跨代遗传现象都是母性效应介导的；极少有父亲经历影响后代的报道。由于这种非常规的信息传递模式不涉及基因组编码的改变，因此被认为是通过表观遗传机制实现的。但目前对这种跨代遗传现象的调控机制、特别是表观机制知之甚少。飞蝗的型变可塑性遗传是很好的研究动物跨代遗传的模型。本项目在通过严谨实验设计消除遗传背景和遗传变异影响的基础上，拟研究（1）父本的种群密度改变对子代群散两型特征的影响；（2）父性效应对子代的重要功能基因和非编码RNA表达的作用；（3）DNA甲基化对型变相关的关键通路分子表达变异的调控。该研究对理解动物的跨代遗传分子机理有重要的科学意义，并将极大促进对蝗灾形成机制的理解。

很多物种具有表型可塑性的跨世代遗传，即双亲经历的环境信息能传递到下一代，导致后代表型发生变异，以适应和亲代类似的环境。但对动物而言，父母亲的经历怎样通过表观遗传影响子代的可塑性，其方式和程度一般不清楚。我们因此开展了如下四个方面的研究并取得重要发现：一、对飞蝗重要型变可塑性特征的父母性遗传研究发现，这些特征可以通过母性遗传也可以通过父性遗传，这些表型特征包括个体大小和形态、后代卵的孵化和发育一致性等。二、对参与发育调节的热激蛋白基因的表达研究发现，种群密度诱导的热激蛋白表达改变可以跨代传递。基于自然突变体的研究发现热激蛋白Hsp90介导母代光周期对胚胎发育变异的影响。三、对非编码RNA（包括长非编码RNA即lncRNA和miRNA）参与跨代遗传调节作用开展了深入研究，发现lncRNA在胚胎发育的表达具有高度的发育特异性。对飞蝗行为转变过程的一个lncRNA（PAHAL）研究发现，PAHAL调节苯丙氨酸羟化酶基因表达和多巴胺的代谢，并调控飞蝗的两型转变。表达谱揭示许多miRNAs参与胚胎发育，功能研究发现miR-276有效促进飞蝗卵发育的一致性。四，对RNA的m6A修饰研究发现，飞蝗RNA甲基化修饰酶在脑内高表达，m6A与飞蝗的两型转变相关，并能够调控飞蝗的行为转变。上述研究发现对理解动物的跨代遗传分子机理有重要的科学意义，并将极大促进对蝗灾形成机制的理解。