Function of Drosophila Btk29A in wing and abdominal development and relationship with Sol narae

Abstract

Jun N-terminal Kinase (JNK) belongs to Mitogen-activated protein kinase (MAPK) family and performs diverse functions during stress-induced apoptosis, cell proliferation including compensatory proliferation, cell regeneration, and cell migration. However, the endogenous function of JNK is not yet fully understood. It has been recently reported that localized JNK signaling acts in wing development. In this thesis, I report that a mutant allele of Btk29A is identified as a suppressor of lethality induced by overexpressed Sona, and Btk29A functions as a regulator of JNK signaling in wing development. Cells in $Btk29A^{m10}$ clones showed caspase-dependent apoptosis whereas knockdown of Btk29A results in smaller wings that are not rescued by anti-apoptotic protein, p35. Overexpression of Btk29A causes apoptosis mediated by canonical JNK upregulation in wing development. In addition, Btk29A functions in larva epithelial cells (LEC) during abdomen development. Without Btk29Afunction, the depletion of LEC is not completed. On the other hand, Sol narae (Sona) is the only function in the histobalsts that form the adult abdomen.