AUTHOR=Albishi Najla M. , Palli Subba Reddy 

TITLE=Autophagy genes AMBRA1 and ATG8 play key roles in midgut remodeling of the yellow fever mosquito, Aedes aegypti

JOURNAL=Frontiers in Insect Science

VOLUME=3

YEAR=2023

URL=https://www.frontiersin.org/journals/insect-science/articles/10.3389/finsc.2023.1113871

DOI=10.3389/finsc.2023.1113871

ISSN=2673-8600

ABSTRACT=<p>The function of two autophagy genes, an activating molecule BECN1 regulated autophagy (AMBRA1) and autophagy-related gene 8 (ATG8) in the midgut remodeling of <italic>Aedes aegypti</italic> was investigated. Real-time quantitative polymerase chain reaction (RT-qPCR) analysis of RNA samples collected from the last instar larvae and pupae showed that these two genes are predominantly expressed during the last 12 h and first 24 h of the last larval and pupal stages, respectively. Stable ecdysteroid analog induced and juvenile hormone (JH) analog suppressed these genes. RNA interference (RNAi) studies showed that the ecdysone-induced transcription factor E93 is required for the expression of these genes. JH-induced transcription factor krüppel homolog 1 (Kr-h1) suppressed the expression of these genes. RNAi-mediated silencing of <italic>AMBRA1</italic> and <italic>ATG8</italic> blocked midgut remodeling. Histological studies of midguts from insects at 48 h after ecdysis to the final larval stage and 12 h after ecdysis to the pupal stage showed that <italic>ATG</italic> gene knockdown blocked midgut remodeling. <italic>AMBRA1</italic> and <italic>ATG8</italic> double-stranded (dsRNA)-treated insects retained larval midgut cells and died during the pupal stage. Together, these results demonstrate that ecdysteroid induction of <italic>ATG</italic> genes initiates autophagy programmed cell death during midgut remodeling. JH inhibits midgut remodeling during metamorphosis by interfering with the expression of ATG genes.</p>