Sex, spores and conquering continents

Supervisors
Professors Beerling, Blackmore, Fleming & Wellman

Key Words: land plant evolution, evo-devo, Selaginella, heterospory, ultrastructure

Description of Project (UG audience) (250 words)
The invasion of the land by plants was one of the most far-reaching chapters in the history of the Earth. It proceeded in a step-wise fashion, driven by evolutionary innovation in reproductive strategy. A key advance was differentiation into a large female megaspore and small male microspore (termed heterospory). This presaged the evolution of seeds upon which terrestrial biodiversity and modern agriculture depends. The project will address the central evolutionary question: which genes were recruited during land plant evolution to enable heterospory and ensure terrestrial success?
The project will focus on the living clubmoss Selaginella (below) that is a member of the ancient primitive lineage of heterosporous plants. Selaginella produces large megaspores with a thick protective wall. The wall is constructed from sporopollenin synthesized by an active tapetum layer in the enclosing sporangium. Molecular genetic analyses of flowering plants (Arabidopsis) have identified numerous genes involved in tapetal function, but the evolution of this ‘genetic tool kit’ remains poorly understood. We will exploit recent advances in molecular genetics, including the sequencing of the Selaginella genome, to identify which of the angiosperm tapetum-specific genetic elements are present and which have an ancient conserved function. The project brings together expertise in spore evolution and structure (Blackmore, Wellman), land plant evolution (Beerling, Blackmore, Fleming, Wellman,) and developmental molecular biology (Fleming) in a modern approach to a classical problem.
The student will gain experience of cutting-edge molecular biology techniques (gene expression analysis, bioinformatics, genetic complementation experiments) in conjunction with novel cryogenic ultrastructural analyses provided by the CASE partner.

To apply, please complete an online application form which can be found at www.shef.ac.uk/postgraduate/research/apply/applying
The closing date is 15th January 2013