Molecular genetic analysis of the neurobiology of tidal clocks in a marine crustacean.

Circadian (24 hour) body clocks are conserved amongst terrestrial organisms, adapting them to the daily solar cycle. A greater diversity and abundance of life, however, inhabits environments varying over tidal/lunar time. Work by our group and others has established a molecular/genetic paradigm for circadian timing, conserved across diverse taxa, involving delayed negative feedback by circadian proteins on expression of the circadian “clock genes” encoding them. In contrast, absolutely nothing is known of the molecular neurobiology of tidal clocks and the behavioural rhythms they drive. This rich neurobiological problem is virgin territory. We shall investigate tidal timing in the isopod crustacean Eurydice pulchra. An inhabitant of UK beaches, it emerges from the sand to feed on flood tides and re-burrows before the ebb carries it away. In the laboratory under constant environmental conditions, it exhibits beautiful circa-tidal activity cycles, with a period ranging between 11.5 and 13.5 hours. Activity is coincident with the predicted high water on the home beach and can be shifted by vibration (mimicking wave action). The underlying molecular neurobiology of this exquisitely precise behaviour is unknown.

This project will utilise sequencing and genomic analyses, homology cloning, RNAseq, behavioural analyses, protein expression and neurobiological analyses of Eurydice nervous system to characterise the molecular genetics behind this elusive clock. The Applicant will be well supported by resources and expertise of LMB and also by ongoing collaborations with Marine Biology groups (Webster, Wilcockson) and Drosophila neurogeneticists (Kyriacou). Candidates should have competence and interest in molecular genetics and neurobiology, including PCR, DNA cloning, genomic sequence analysis, immunohistochemistry and in situ hybridisation. We shall identify tidal genes and then examine their functions in cell culture and in vivo. Is the tidal clock a shorter cycle equivalent of the circadian feedback loop or is it something more exotic? Our recently published work (see below) suggests that the tidal clock is altogether something different.

Recent first-author papers from previous PhD students in Hastings group:

Edwards et al. PNAS (2016).
Smyllie et al. PNAS (2016).
Smyllie et al. Current Biology (2016).