Supervisors:

PI: Gabriele Gerlach, Co-PIs: Thorsten Dittmar, Peter Schupp, Thorsten Brinkhoff

Research and projects

Numerous organisms have developed endogenous clocks, which synchronizes their metabolism, physiology and behaviour with environmental rhythms such as light/dark/lunar/tidal-cycle, temperature changes and or rhythmical food supply. Endogenous clocks control adaptation to circadian changes, but also to seasonal rhythms.

In Antarctic krill (Euphausia superba Dana, 1850) clock genes and functional endogenous clocks were characterized on a transcriptome and physiological level. Different seasonal and circadian behaviours were observed, influencing seasonal migration and metabolism of krill. The seasonal changes in the Southern Ocean are extreme. The light/dark-cycle changes from 24 h per day sun to complete darkness. An adaptation of the endogenous rhythm to these natural conditions are crucial for survival and reproduction and might differ between populations because the time of sunlight and the resulting parameters strongly differ dependent on latitude and longitude. In the first step of this doctoral thesis I will analyse, whether different krill populations show DNA based differences in their clock gene repertoire. I will conduct a population genetic analysis in different Antarctic krill populations based on existing neutral microsatellite markers and those that are linked on clock genes, as well as SNP differences in clock related genes.

In a second step I will use the findings on clock genes and their genetic expression to understand clock dependent migration in other marine organisms such as larval coral reef fish, which conduct species dependent dispersal before they settle at a reef. Clownfish are living in coral reefs in the tropical area. They leave their home reefs shortly after hatching and spent up to 12 days in the pelagial until the settle to a reef. I will test the hypothesis that the duration of dispersal is influenced or controlled by an endogenous clock. In laboratory reared clownfish I will conduct transcriptome analysis to identify and characterize clock genes and quantify their genetic expression at different dispersal stages using quantitative real-time PCR and gene knockout methods.

In this dissertation, I will investigate clock genes and understand their role in dispersal and migration processes also in different taxa.