Screening of genes that regulate the maintenance of synapse during aging of Drosophila melanogaster
Authors: Danielle Moreira; Jessica Sidisky; Daniel Babcock
Affiliation: Department of Biological Sciences, Lehigh University, Bethlehem, PA
Keywords: l. locomotion/flight; a. neural degeneration
The maintenance of synapses is dependent on several coordinated mechanisms, which involve cell-to-cell communication, molecules recycling and degradation. However, the mechanism that controls the synapse maintenance during aging is poorly understood. Here, we investigated the synapse maintenance at the neuromuscular junction (NMJ) of adult Drosophila melanogaster lines. Using a flight behavior tester, we evaluated the flight ability of 205 inbred fly lines from the DrosophilaGenetic Reference Panel (DGRP), which harbor known SNP and non-SNP variants in or near genes, during aging. To flight test, we collected flies, which were reared on an incubator at 25°C for 1- or 2-days post pupae eclosion, separated by sex and matured them for 3 days and 21 days on an incubator at 29°C. We observed a widely variable flight ability in the DGRP lines from day 3 to day 21 during aging. However, 10 out of 205 DGRP lines had the most expressive decline of the flight ability during aging. To validate these findings, we tested mutant flies for these 10 genes and observed that these genes are prone to cause progressive loss of flight ability. In addition, to identify how these genes cause disruption on tripartite synapse of the neuromuscular junction (NMJ), we used a UAS-Gal4 system to direct the knockdown of those genes on glia (Repo-Gal4), muscle (MHC-Gal4) and motor neuron (BG380-Gal4). Knocking down the 10 genes on muscle and/or motor neurons led to flight ability decline, but one out of the 10 genes caused a progressive defect of the flight behavior directed by the glial driver. To further understand the cellular alterations on synapse at the NMJ, we are characterizing the morphology of the pre- and post-synaptic components. Our data is highlighting the mechanism regulating the synapse maintenance during aging and the progressive degeneration of the synapse cellular components.