Epigenetics of non-model organisms

模式生物是世纪大部分时间里研究的支柱。在某种程度上，选择模式生物是因为它们的直接发育和恒定的形态。然而，快速基因组测序的出现和分子工具向非传统模式生物的迅速转移模糊了模式生物、新兴模式生物和非传统模式生物之间的界限。非传统模式生物的更复杂的生活史为我们提供了一个独特的机会来扩展我们对生物学的理解。 我提议的研究计划将探索非传统模式生物学的表观遗传基础。 例如，果蝇像老鼠和人类一样，在发育过程中对适度营养缺乏的反应，没有什么比发育成更小的成年人更令人兴奋的了。相反，水蚤对不利的环境条件的反应是产生额外的性别-雄性。同样，在捕食者的存在下，水蚤的形态被严重重塑，动物可以产生巨大的头盔，尾刺，棍棒，颈齿和其他形态上的精心制作，完全改变了它们的外观。这些丰富的形态变化必然是表观遗传的，因为它们发生在具有相同基因组的克隆中。这些戏剧性的和生物学上必要的表观遗传反应证明了非传统模式生物的优势。 表观基因组反映了基因表达中的一系列表观遗传变化;也就是说，基因表达的变化不是由于DNA序列的改变。表观基因组对外部环境因素，如营养，毒素暴露，激素环境，社会互动，甚至可能是天气。细胞内部环境的影响，特别是内细菌的影响，文献记载较少。在内细菌中，具有专性细胞内繁殖的细菌，α-变形菌可以说是最著名的，因为该组的一个古老成员产生了我们的线粒体。然而，这种普遍存在的细菌群还包括较少驯化的现存亲属，沃尔巴克氏体和立克次体，分别是无脊椎动物和脊椎动物的专性内细菌。 我将扩展我们的工作在果蝇的内生细菌的表观遗传效应，探索他们的控制其主机的基因组在非传统的模型系统，水蚤，蜱和哺乳动物细胞培养。无处不在的内细菌控制其宿主的多种方式，从而影响宿主的表型和生物学，是本研究计划将解决的问题。

Model organisms have been the mainstay of research for much of the 20th century. In part, model organisms have been selected for their straightforward development and constant morphology. However, the advent of rapid genome sequencing and the ready transfer of molecular tools to non-traditional model organisms have blurred the lines between model, emerging and non-traditional model organisms. The more complex life histories of non-traditional model organisms provide a unique opportunity to expand our understanding of biology. My proposed research program will explore the epigenetic foundation of the biology of non-traditional model organisms. For example, Drosophila like mice and humans, responds to modest nutrient deprivation in development by nothing more exciting than developing as smaller adults. In contrast, Daphnia responds to adverse environmental circumstances by producing an additional sex - males. Similarly, in the presence of predators, the morphology of Daphnia is grossly remodeled and the animals can produce massive helmets, tail spines, clubs, neck teeth and other morphological elaborations that completely change their appearance. These exuberant morphological changes are necessarily epigenetic, as they occur in clones with identical genomes. These dramatic and biologically essential epigenetic responses demonstrates the advantages of non-traditional model organisms. The epigenome reflects the suite of epigenetic changes in gene expression; that is, changes in gene expression not due to altered DNA sequence. The epigenome is responsive to external environmental factors such as nutrition, toxin exposure, hormonal milieu, social interactions, and possibly even the weather. Less well documented is the effect of the internal environment of cells, in particular the effect of endobacteria. Among the endobacteria, bacteria with obligate intracellular reproduction, a-proteobacteria is arguably the most famous, as an ancient member of this group gave rise to our mitochondria. However, this ubiquitous group of bacteria also includes less domesticated extant relatives, Wolbachia and Rickettsia, obligate endobacteria of inverterbrates and vertebrates, respectively. I will extend our work on the epigenetic effects of endobacteria in Drosophila by exploring their control of their host's genome in the non-traditional model systems, Daphnia, ticks and mammalian cell culture. The manifold ways in which ubiquitous endobacteria control their host, and so influence host phenotype and biology, are the questions that will be tackled in this research programme.