DROSOPHILA MELANOGASTER SELECTED MUTANTS’ RESPONSES TOENTOMOPATHOGENIC FUNGI METARHIZIUM ANISOPLIAE STRAIN ME1
Authors: Paschalis Giannoulis
Paschalis Giannoulis: Department of Agriculture, Faculty of Agricultural Sciences, University of Patras, New Buildings, 30200 Missolonghi, Greece.
ABSTRACT
Host-response variability to M. anisopliae was examined across D. melanogaster genotypes differing in immune signaling reporters and cuticular melanization, with particular focus on the yellow (y1; melanin-deficient) and ebony (e11; hypermelanic) mutants alongside a GFP-drs/lacZ-dpt reporter mutant. Flies were reared under controlled conditions (25°C, 12:12 h photoperiod) and challenged with M. anisopliae strain ME1. Third-instar larval bioassays used defined inocula (2 × 106 – 2 × 108 sp/ml) and multiple exposure modes and responses were quantified as macroscopic melanization, escape from infection (absence of melanic patches) and pupation timing; developmental suppression assays monitored oviposition, larval emergence, pupation, and eclosion. Both wild type and the GFP-drs/lacZ-dpt mutant showed sigmoidal, dose-dependent melanization, with higher inocula reducing latency in melanic patch emergence; genotype effects were modest, supporting the GFP-drs/lacZ-dpt mutant as a useful monitoring tool. In contrast, y1 exhibited strong dose-dependent suppression across development and increased susceptibility, consistent with compromised melanin-associated barrier protection, whereas e11 showed rapid full-body melanization and comparatively greater resistance despite clear pathogenic load effects at 108 spores/ml.
Keywords: Drosophila mutants; Microbial insecticides; Fungal Pathogenicity; Host responses