Queen Mary University of London is announcing an exciting opportunity for an allocated four-year PhD position in either the Earth Surface Science group in the School of Geography or the Evolution and Development group in the School of Biological and Chemical Sciences. The successful candidate will start their project in September 2019 and will participate in training and cohort activities of the London NERC DTP.
The London NERC Doctoral Training Partnership brings together eight of the world’s leading research centres in environmental science. Our partnership provides innovative doctoral training in a multidisciplinary research environment and fosters links between centres of research excellence, spanning NERC’s environmental science remit.
About the Project
The sense of olfaction enables animals to detect, recognise and respond to chemicals in their environment, which is critical for survival and reproduction. A key breakthrough in our understanding of the mechanisms of olfaction was the discovery of a large family of genes that encode G-protein coupled odorant receptors in humans and other vertebrates, which was recognised in the award of the 2004 Nobel Prize for Physiology or Medicine. Subsequently, it has been discovered that different families of genes have evolved as mediators of olfaction in other taxa; e.g. in arthropods two families of genes encoding ion channels mediate olfaction. Therefore, characterisation of odorant receptors in a variety of phyla is now needed if we are to understand the evolution of mechanisms of olfaction.
The aim of the project proposed here will be to address this objective by analysing the molecular mechanisms of olfaction in an animal that occupies an “intermediate” phylogenetic position with respect to vertebrates and arthropods – the starfish Asterias rubens (phylum Echinodermata). Informed by analysis of genome sequence data, we have recently identified several candidate odorant receptor genes in A. rubens and the proposed project will build upon these preliminary findings to investigate the mechanisms of olfaction by addressing the following objectives:
Objective 1 (year 1): Genome-wide discovery of odorant receptor genes in A. rubens – Informed by the complementary expertise of the Wurm and Elphick in comparative genomics, a detailed analysis of A. rubens genome sequence data generated by the Sanger Institute will be performed to identify candidate odorant receptor genes. By analysing gene number, structure, synteny and phylogenetics, important new insights into the evolution of odorant receptor genes in starfish and other echinoderms will be obtained.
Objective 2 (year 1-2): Mapping odorant receptor gene expression in starfish “noses” – Located at the tips of each of the five arms of starfish is a terminal tentacle with associated sensory organs, which include an optic cushion and flaps of tissue known as lappets, which are the presumptive olfactory organs or “noses”. Transcriptome sequencing and mRNA in situ hybridisation methods will be used identify putative odorant receptor genes that are expressed by cells located in sensory (olfactory) organs located at the tips of starfish arms.
Objective 3 (year 2-3): Identification of pheromone receptors in starfish - Here the student will focus in on a more specific objective of identifying odorant receptors involved in starfish reproduction. Release of eggs or sperm in starfish is triggered by a relaxin-like gonadotropic peptide (RGP) and we have recently discovered that RGP is expressed by cells located in the lappets of the terminal tentacles (Lin et al. 2017a). Our hypothesis is that activation of pheromone receptors co-expressed with RGP triggers the release of RGP to induce spawning. The objective here will be to identify receptors that are activated by chemicals (pheromones) released with eggs or sperm by conspecifics when they spawn and to accomplish this the student will repurpose an in vitro cell-based assay that we have used successfully to identify ligands for G-protein coupled neuropeptide receptors (Tian et al., 2016). Then use of double mRNA in situ hybridisation will enable identification of pheromone receptors that are co-expressed with RGP.
For further information about each topic please contact the relevant supervisor. Candidates are strongly advised to make contact with the potential supervisor to discuss these opportunities prior to application for funding.
Please note: NERC funding is subject to candidates meeting RCUK eligibility criteria and we encourage eligible students from the EU to apply. For details of eligibility please click here: https://london-nerc-dtp.org/apply-to-the-london-nerc-dtp/#eligibility
How to Apply
Applicants should include a supporting statement, CV, transcripts and certificates, details of two referees, and indicate the relevant supervisor and project title in the application form. Shortlisted candidates will be invited to interview in March 2019.
To apply for a studentship being advertised by the School of Biological and Chemical Sciences (SBCS) please click here: https://mysis.qmul.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RFQM-C1ZF-09&code2=0010
To apply for a studentship being advertised by the School of Geography please click here: https://mysis.qmul.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RFQM-L8ZM-09&code2=0010&code3=GUEST
Deadline for applicants: Monday 18 March 2019