Google Scholar Citations: https://scholar.google.com/citations?hl=en&user=hB2hYfwAAAAJ
Most insects undergo metamorphosis to develop into adults. The brains of holometabolous insects show drastic morphological changes during pupa, which are required to prepare for adult-specific behaviors. However, the brains of not all insects face drastic morphogenesis during postembryonic development. Approximately 10% of insect species belong to the evolutionary basal direct-developing insects, which develop into adults without pupation. Like holometabolous insects, adults of direct-developing insects exhibit adult-specific behaviors such as courtship and mating behaviors, which are not observed in juveniles. This raises a question from the viewpoint of evolutionary developmental biology: when and how the brain of basal direct-developing insects becomes adult brain without the pupal stage?
To address this question, Takayuki Watanabe is investigating the development of the neural circuits for adult-specific behaviors in a model hemimetabolous insect Gryllus bimaculatus (two-spotted cricket). In the current project, he focuses on the sexually dimorphic circuits which may regulate sexually dimorphic behaviors such as courtship and ritual agonistic behaviors in adult crickets, and reveals the molecular basis and evolution of the neural sex-determination system in basal direct-developing insects. Besides, he is establishing genetic techniques (i.e., transgenesis and genome editing) to the cricket for developmental and functional analyses of sexually dimorphic circuits in the cricket brain.