This work package includes 2 projects.
We have recently discovered a change in the mitochondrial respiration dynamics of Drosophila larvae at low temperatures that induce diapause, that is not observed in adults, and which leads to larval death. We believe this might explain why Drosophila overwinters as adults, and we propose to study this by using CRISPR/Cas9 mutagenesis of the gene we believe might be responsible, Ucp4c. We shall extend this analysis to pest species, D. suzukii, the Medfly and Olive fly. Should these different species developmental diapause phenotypes (larva, pupa or adult) correlate with mitochondrial dynamics, we might have a target for disrupting diapause in pests. Drosophila has a single gene encoding HO (heme oxygenase) that plays an important role in development and in controlling the DNA damage signalling pathway. We have observed that in the Drosophila retina ho is cyclically expressed with two peaks, at the beginning of the day and in the middle of the night. Modulating HO levels alters clock gene expression so we will induce various stresses, cold, heat, chemical and investigate HO and clock gene expression levels as well as exposing flies to antioxidants to see whether they have beneficial effects on fly sleep and circadian behaviour.
Title: Mitochondrial metabolism and seasonality in Drosophila
Host Institution: University of Padova
Supervisor: Prof Rodolfo Costa
Secondment: University of Leicester for three months to investigate other mitochondrial phenotypes and Oxitec for two months to learn Medfly and Olive fly biology and transgenesis.
Objectives: To discover whether uncoupled respiration has evolved as a transient adaptation favouring progression of larvae into more cold‐tolerant developmental stages such as the adult. Drosophila larvae show uncoupled mitochondrial respiration at low temperatures and cannot survive, whereas adults exhibit coupled respiration and survive under these conditions by moving into diapause. This difference may be mediated by the gene Ucp4c. The project will use a genetic approach to study the signalling pathway that generates uncouples versus coupled mitochondrial respiration in Drosophila and pest species.
Title: Environmental stress and the clock in Drosophila
Host Institution: Jagiellonian University (Krakow)
Supervisor: Prof Elzbieta Pyza
Secondment: University of Padova for 4 months for generating molecular constructs for mutagenesis.
Objectives: To investigate the role of neuronal and glial Heme oxygenase (HO) on the circadian clock and associated phenotypes after stress. HO plays a role in the DNA damage signalling pathway and shows two peaks of expression during the day that are regulated by the clock. Furthermore changes in HO expression alter circadian behaviour. We shall examine its expression patterns in the brain, particularly synaptic plasticity, under various environmental stresses (hot, cold, pesticide) and asses the DNA damage response in wild type and CRISPR/Cas9 generated ho mutants. We shall also use antioxidants to see if they have beneficial effects under normal and stress conditions.