Effect of pattern recognition receptor LE (PGRP-LE) overexpression in Dredd mutant Drosophila enterocytes

The main goal of this study was to characterize the Dredd-independent functions of PGRP-LE in the adult Drosophila midgut (the midgut is the functional analog of the vertebrate small intestine). We expressed a UAS-PGRP-LE transgene under the control of mex-GAL4, which is specifically active in midgut enterocytes, in a Dredd mutant background. We then collected adult male midguts, extracted total RNA and performed mRNA-seq. Our data show that PGRP-LE overexpression alters fundamental aspects of midgut metabolism in Dredd mutant midguts. Total RNA was extracted from 20 midguts of Dredd mutant adult males (controls - genotype: Dredd D44/Y; mex-GAL4/+), and of Dredd mutant adult males with PGRP-LE overexpression in enterocytes (genotype: Dredd D44/Y; mex-GAL4/UAS-PGRP-LE). mRNA sequencing was performed on 5 biological replicates per genotype. Adult male flies were fed a yeast only diet and dissected 7 days after eclosion.

本研究的核心目标为解析果蝇（Drosophila）成体中肠内不依赖Dredd的PGRP-LE生物学功能，其中中肠为脊椎动物小肠的功能同源类似物。我们在Dredd突变体的遗传背景中，利用仅在中肠肠上皮细胞中特异性激活的mex-GAL4驱动UAS-PGRP-LE转基因表达。随后收集成体雄性果蝇的中肠，提取总RNA并开展mRNA测序（mRNA-seq）。实验数据表明，在Dredd突变体中肠内，PGRP-LE过表达会改变中肠代谢的核心特征。我们分别从两类样本的20份中肠中提取总RNA：一类为对照组，即基因型为Dredd D44/Y; mex-GAL4/+的Dredd突变体成体雄性果蝇；另一类为实验组，即肠上皮细胞过表达PGRP-LE的Dredd突变体成体雄性果蝇，其基因型为Dredd D44/Y; mex-GAL4/UAS-PGRP-LE。每种基因型设置5个生物学重复样本进行mRNA测序。成体雄性果蝇仅以酵母为单一食物源，羽化7天后进行解剖取材。