Growth Control by Hippo Signaling in Drosophila

Growth inhibitory signaling mediated by the Hippo pathway provides an important regulatory mechanism for tissue growth and organ size control in animal development. Loss of Hippo signaling leads to tissue overgrowth and aberrant organ size in animals like fruit flies and mice. Previous studies have identified several key components in this pathway. A central question in this field is how Hippo signaling is activated by upstream components to control tissue growth and organ size. Also, it is not clear how cellular growth is regulated by Hippo signaling. This project will address these questions with molecular and genetic approaches investigating the role of upstream molecules, Expanded, Merlin and Sav, in Hippo membrane localization and activation. Itwill also test a hypothesis that Hippo signaling negatively regulates cellular growth by blocking insulin receptor signaling activities. Hippo membrane localization is expected to be a key step for its activation. Studies on Hippo signaling shall advance our knowledge of how tissue growth and organ size are controlled in animal development. Moreover, this research project provides great opportunities to promote teaching, training, and learning for graduate and undergraduate students. During summers, high school students from an outreach program will come to Dr. Lai's laboratory to gain research experience in developmental biology and genetics. To disseminate research results, the Lai laboratory will publish its work in a timely fashion, regularly attend conferences and give talks in local schools and other institutions to enhance scientific understanding by the community and society.