Meeting Abstract
The genus Drosophila contains over 1,500 species that inhabit diverse habitats including deserts, tropical rainforests, and alpine zones. Despite these varied habitats no species of Drosophila has been shown to tolerate major desiccation, and instead mechanisms to resist water loss have evolved. In animals, expression of late embryogenesis abundant proteins (LEA) is tightly correlated to life cycle stages that are desiccation tolerant. LEA proteins prevent protein aggregation and stabilize membranes during desiccation. We have created D. melanogaster fly lines that express transgenic LEA proteins (AfrLEA2 or AfrLEA3m), which are naturally accumulated in desiccation tolerant cysts of Artemia franciscana. Western blots confirmed that AfrLEA proteins are expressed in our transgenic lines of D. melanogaster. To investigate the impact of accumulation of LEA proteins on desiccation tolerance, we dried 18-20 h embryos of D. melanogaster for 4 h at 55% humidity and 22°C. This drying regime removed 80% of embryo water. Embryos then were rehydrated and scored for eclosion 72 and 120 h later. For individuals expressing AfrLEA2 or AfrLEA3m, the number of eclosed embryos 72 h post-rehydration was modestly lower than that observed for non-dried embryos [90.2 ± 13%, ± SD (n=3) and 88.0 ±1.1% (n=3) of non-dried embryos, respectively]. Eclosion of dried control embryos (without either LEA protein) was significantly lower at 72 h post-rehydration compared to embryos expressing LEA proteins [8.8 ± 8% (n=3) of non-dried embryos, one-way ANOVA, p < 0.05] and increased after 120 h of rehydration to 64.4 ± 44% (n=3). These data show that expression of AfrLEA proteins significantly reduce recovery time after desiccation in D. melanogaster embryos. [Supported by NSF grant IOS-1457061/IOS-1456809]
