RNA sequencing of aphid galls
Insects are an extremely species-rich and diverse taxonomic group that includes many species with sophisticated ecologies. Specifically, gall-forming insect species induce various types of galls on their host plants by altering gene expression in host plant organs, and recent studies have been conducted to reveal gene expression in galls. However, the evolutionary trajectories of gene expression patterns and the resulting phenotypes have not yet been studied using several related species. The objective of this study is to investigate the diversification process of galls induced by four closely related aphid species (Aphididae: Hormaphidini) in a host plant species (Hamamelis japonica) by comparing their gene expression patterns and resulting phenotypes. We  try to reveal the evolutionary process of phenotypic traits in galls in the wild from both microlevel and macrolevel perspectives.