Essential Roles of the Tap42-Regulated Protein Phosphatase 2A (PP2A) Family in Wing Imaginal Disc Development of <em>Drosophila melanogaster</em>

<div><p>Protein ser/thr phosphatase 2A family members (PP2A, PP4, and PP6) are implicated in the control of numerous biological processes, but our understanding of the <em>in vivo</em> function and regulation of these enzymes is limited. In this study, we investigated the role of Tap42, a common regulatory subunit for all three PP2A family members, in the development of <em>Drosophila</em> m<em>elanogaster</em> wing imaginal discs. RNAi-mediated silencing of <em>Tap42</em> using the binary <em>Gal4/UAS</em> system and two disc drivers, <em>pnr-</em> and <em>ap-Gal4</em>, not only decreased survival rates but also hampered the development of wing discs, resulting in a remarkable thorax cleft and defective wings in adults. Silencing of <em>Tap42</em> also altered multiple signaling pathways (HH, JNK and DPP) and triggered apoptosis in wing imaginal discs. The <em>Tap42^RNAi</em>-induced defects were the direct result of loss of regulation of <em>Drosophila</em> PP2A family members (MTS, PP4, and PPV), as enforced expression of wild type Tap42, but not a phosphatase binding defective Tap42 mutant, rescued fly survivorship and defects. The experimental platform described herein identifies crucial roles for Tap42•phosphatase complexes in governing imaginal disc and fly development.</p>