The Drosophila homologue of MEGF8 is essential for early development

Deborah L Lloyd,Andrew O M Wilkie,Markus Toegel,Tudor A Fulga

doi:10.1038/s41598-018-27076-y

Deborah L Lloyd, Andrew O M Wilkie + Show 2 more

Open Access

https://doi.org/10.1038/s41598-018-27076-y

Copy DOI

Abstract

Mutations of the gene MEGF8 cause Carpenter syndrome in humans, and the mouse orthologue has been functionally associated with Nodal and Bmp4 signalling. Here, we have investigated the phenotype associated with loss-of-function of CG7466, a gene that encodes the Drosophila homologue of MEGF8. We generated three different frame-shift null mutations in CG7466 using CRISPR/Cas9 gene editing. Heterozygous flies appeared normal, but homozygous animals had disorganised denticle belts and died as 2nd or 3rd instar larvae. Larvae were delayed in transition to 3rd instars and showed arrested growth, which was associated with abnormal feeding behaviour and prolonged survival when yeast food was supplemented with sucrose. RNAi-mediated knockdown using the Gal4-UAS system resulted in lethality with ubiquitous and tissue-specific Gal4 drivers, and growth defects including abnormal bristle number and orientation in a subset of escapers. We conclude that CG7466 is essential for larval development and that diminished function perturbs denticle and bristle formation.

Highlights

Over the past 25 years, investigation into the genetic basis of multiple congenital abnormality syndromes has provided a powerful route to the discovery and functional analysis of novel genes with pleiotropic roles in embryonic development
The majority of dMegf8Δ/Δ mutants died in a short period of time (48 h) between larval days three and five (Fig. 1F), ~2% survived for up to 20 days when their yeast diet was supplemented with sucrose
Despite having deep evolutionary origins and an important role in development, little is known about the function of Multiple Epidermal Growth Factor-like Domains 8 (MEGF8) other than proposed roles in Nodal[8] and BMP7 signalling

Summary

Introduction

Over the past 25 years, investigation into the genetic basis of multiple congenital abnormality syndromes has provided a powerful route to the discovery and functional analysis of novel genes with pleiotropic roles in embryonic development. To explore the in vivo consequences of dMegf[8] LOF, we used CRISPR-Cas[9] gene editing to generate three independent null mutant stocks (dMegf8Δ1, dMegf8Δ4, dMegf8Δ8) (Fig. 1B).

Results

Conclusion