AUTHOR=Mo Dongqing , Chen Yao , Jiang Na , Shen Jie , Zhang Junzheng 

TITLE=Investigation of Isoform Specific Functions of the V-ATPase a Subunit During Drosophila Wing Development

JOURNAL=Frontiers in Genetics

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2020.00723

DOI=10.3389/fgene.2020.00723

ISSN=1664-8021

ABSTRACT=<p>The vacuolar ATPases (V-ATPases) are ATP-dependent proton pumps that play vital roles in eukaryotic cells. Insect V-ATPases are required in nearly all epithelial tissues to regulate a multiplicity of processes including receptor-mediated endocytosis, protein degradation, fluid secretion, and neurotransmission. Composed of fourteen different subunits, several V-ATPase subunits exist in distinct isoforms to perform cell type specific functions. The 100 kD a subunit (Vha100) of V-ATPases are encoded by a family of five genes in <italic>Drosophila</italic>, but their assignments are not fully understood. Here we report an experimental survey of the <italic>Vha100</italic> gene family during <italic>Drosophila</italic> wing development. A combination of CRISPR-Cas9 mutagenesis, somatic clonal analysis and <italic>in vivo</italic> RNAi assays is used to characterize the requirement of Vha100 isoforms, and mutants of <italic>Vha100-2</italic>, <italic>Vha100-3, Vha100-4</italic>, and <italic>Vha100-5</italic> genes were generated. We show that <italic>Vha100-3</italic> and <italic>Vha100-5</italic> are dispensable for fly development, while <italic>Vha100-1</italic> is not critically required in the wing. As for the other two isoforms, we find that <italic>Vha100-2</italic> regulates wing cuticle maturation, while <italic>Vha100-4</italic> is the single isoform involved in developmental patterning. More specifically, <italic>Vha100-4</italic> is required for proper activation of the Wingless signaling pathway during fly wing development. Interestingly, we also find a specific genetic interaction between <italic>Vha100-1</italic> and <italic>Vha100-4</italic> during wing development. Our results revealed the distinct roles of <italic>Vha100</italic> isoforms during insect wing development, providing a rationale for understanding the diverse roles of V-ATPases.</p>