Principal Supervisor: Dr Scott Hayward, School of Biosciences
Co-supervisor(s): Professor John Kenneth Colbourne, School of Biosciences; Dr Luisa Orsini, School of Biosciences
PhD project title: Climate change and pesticides: molecular and physiological processes underpinning pollinator responses to stress.
University of Registration: University of Birmingham
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. Pollinators are in severe decline however, encountering stressors on multiple fronts: climate change, pesticides, pathogens, parasites, etc. While omic technologies have greatly enhanced our understanding of the molecular processes underpinning responses to individual stressors 1, few studies have considered how multiple stressors interact. This project will employ state-of-the-art physiological and molecular techniques to investigate how a key UK pollinator responds to combined stress events, and the impact on survival/tolerance thresholds.
Virtually all temperate insects, including most pollinators, survive winter in a state of dormancy – diapause 2. A primary driver of pollinator decline at temperate latitudes is climate change disruption of diapause, because it leaves bees vulnerable to winter cold 3. In combination, bees are exposed to increasing quantities and different cocktails of pesticides. However, we currently have a very poor understanding of how pesticide exposure might influence the regulation of diapause, or its impact on cold tolerance/winter survival. For some species, disruption of diapause can be catastrophic due to severe population bottlenecks during winter, e.g. for the bumblebee Bombus terrestris, it is only queens that enter diapause, while all workers and males die during autumn.
B. terrestris is an ideal study system for many reasons: an important pollinator of key crops globally; commercially produced on a massive scale to supplement natural populations; highly tractable for molecular studies. 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 genome-wide in a single assay. In addition, RNAi knockdown has been successfully employed in this species4, permitting functional analysis of gene transcripts underpinning diapause and stress responses. In a commercial setting this could have fundamental applications in e.g.controlling diapause duration and/or cold tolerance to then facilitate long term cold storage of bees helping make them available ‘off the shelf’.
Core objectives are to: i) Characterise gene expression networks underpinning diapause. ii) Determine the impact of pesticide exposure on diapause regulation and winter survival. iii) Develop new molecular and physiological methods to enhance commercial pollinator culturing practises.
- Hayward S. A. L. (2014) Application of functional ‘Omics’ in environmental stress physiology: insights, limitations, and future challenges. Current Opinion in Insect Science 4: 35-41.
- Bale, J. S. and Hayward, S. A. L. (2010) Insect overwintering in a changing climate. Journal of Experimental Biology 213: 980-994.
- Owen, E. L., Bale, J. S. and Hayward, S. A. L. (2013) Can winter-active bumblebees survive the cold? Assessing the cold tolerance of Bombus terrestris audax and the effects of pollen feeding. PLoS ONE 8: e80061
- Deshwal S. and Mallon E. B. (2014) Antimicrobial peptides play a functional role in bumblebee anti-trypanosome defense. Developmental and Comparative Immunology 42: 240–243
BBSRC Strategic Research Priority: Food Security
Techniques that will be undertaken during the project:
All supervisors are based within the Biosystems and Environmental Change (BEC) theme, and the DR will interact on a 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.
Through collaboration with/exposure to established industry partners involved in the commercial production of pollinators, the DR will also gain unique training at the interface of academic biological research and industry.Conatct:Dr Scott Hayward, School of Biosciences