Enhancing food security through understanding pollinator dormancy (diapause).

Establishing agricultural resilience and food security in the face of environmental change is of intense global interest, and pollinators will play a key role in achieving this objective. Agriculture cannot rely on natural pollinator populations alone, as many of these are in severe decline. Thus, pollination service provision is dependent on the commercial production of key species such as the bumble bee Bombus terrestris. In common with most temperate insects, B. terrestris enters a period of dormancy, termed diapause, to survive winter under natural conditions. More uniquely, it is only mated queens that enter diapause and persist to establish new colonies the following year1. Insect diapause is typically induced by changes in day/night length, with increasing night length signalling the advent of winter. However, to date, there are no published studies on the mechanism of diapause induction in B. terrestris. Temperature and diet can also have a significant influence on diapause characteristics, including incidence, duration, stress tolerance and postdiapause
fitness2, but this has rarely been studied in pollinators.
The B. terrestris genome has been sequenced, and recent advances in high-throughput cDNA sequencing (RNA-seq) can reveal new genes and splice variants and quantify expression genomewide in a single assay. In addition, RNAi knockdown has been successfully employed in this species3, permitting functional analysis of transcripts uniquely up-regulated within the diapause programme.
Thus, B. terrestris represents an ideal system to dissect mechanisms of diapause regulation.
In a commercial setting diapause is extremely useful as it allows the long-term cold storage of bees. However, diapause can also represent an unwanted delay in population turnover. Currently, commercial providers have a very limited understanding of how to manipulate the diapause state, or the molecular mechanisms that underpin key diapause characteristics – which represent potential targets for manipulation. Yet this has fundamental applications in controlling life cycle duration, synchronising availability with demand, providing a year round supply ‘off-the-shelf’, as well as maximising the fitness of supplied bees.

Core objectives: i) Determine the impact of temperature and diet manipulations on diapause incidence, duration and post-diapause fitness, in order to optimise commercial culturing practise; ii) Provide the first detailed characterisation of changes in gene expression underpinning diapause in any bee species. Thus providing insights into the mechanisms underlying the physiological specialization associated with diapause, and possible targets for manipulation.

Key experimental skills involved:
Both SH and JC are based within the Biosystems and Environmental Change (BEC) theme, and the DR will interact on daily basis with researchers at the vanguard of applying systems biology approaches to understanding organismal responses to environmental change. The SH lab has extensive experience in working with many different insect systems, including ongoing projects with B. terrestris.
The DR will receive training in the use of extensive insect culturing and climate control facilities, as well as state-of-the-art omic technologies. Specialist training will be given in high throughput sequencing of B. terrestris transcripts (RNA-seq), spanning the processes from sample extraction to the bioinformatic analysis of the data generated. Training will also be given in the use of RNAi to knock-down the expression of diapause-associated transcripts.

There are also opportunities to collaborate with established industry partners involved in the commercial production of pollinators, gaining unique insight at the interface of academic biological research and industry.

Please find additional funding text below. For further funding details, please see the ‘Funding’ section.
The School of Biosciences offers a number of UK Research Council (e.g. BBSRC, NERC) PhD studentships each year. Fully funded research council studentships are normally only available to UK nationals (or EU nationals resident in the UK) but part-funded studentships may be available to EU applicants resident outside of the UK. The deadline for applications for research council studentships is 31 January each year.

Each year we also have a number of fully funded Darwin Trust Scholarships. These are provided by the Darwin Trust of Edinburgh and are for non-UK students wishing to undertake a PhD in the general area of Molecular Microbiology. The deadline for this scheme is also 31 January each year.