Primary Supervisor - Prof Thomas Mock
Secondary Supervisor - Prof Cock van Oosterhout
Supervisory Team - Dr Glen Wheeler
Diatoms are the main primary producers in polar oceans, where photosynthesis is largely limited by seasonal fluctuation in light, temperature, and the extent of sea ice. Additionally, trace metals such as iron and zinc play an important role in controlling the biomass of primary producers. Polar diatoms have a particularly high demand for zinc, thereby largely determining zinc distribution throughout the global ocean.
The reason for the enhanced requirement of zinc in polar diatoms remains enigmatic. However, the first genome sequences from a polar diatom and other cold-adapted algae revealed adaptive expansions of gene families containing zinc-binding domains. The elevated concentrations of zinc in polar oceans may thus have aided the expansion of these zinc-binding domains. As specific gene families involved in photosynthesis and carbon fixation were both co-expanded and co-expressed, it suggests that zinc plays an important role in supporting photosynthetic growth in polar phytoplankton. Hence, zinc may be the reason why there are complex life forms in polar oceans, because phytoplankton underpin polar food webs.
The main aim of this project is to produce the first molecular genetics and biochemical data on the role of zinc in the physiological adaptation of cold-adapted diatoms. The student will work in the laboratory with a cold-adapted model diatom and will apply the latest reverse genetics tools in combination with sequencing and photosynthesis measurements (e.g., carbon acquisition, quantum yield) to characterise the role of conserved low-temperature inducible regulatory genes with zinc-binding domains that are co-regulated with photosynthesis genes. A combination of these experimental approaches together with an evolutionary analysis will provide first insights into the role of zinc-binding domains in supporting photosynthesis in polar marine microalgae.
The student will gain skills in the latest reverse-genetics tools such as CRISPR-Cas and sequence analyses, algal cultivation, photosynthesis measurements, protein biochemistry, bioinformatics and evolutionary biology.