Inheritance patterns affecting immune function across European blue mussel hybrids at the University of Edinburgh

This project aims to investigate how blue mussel subspecies hybridisation affects their ability to overcome increasing challenges of climate change and disease.

Apply by Thursday January 06 2022 at 12.00

Project background

As reef-building filter feeders, blue mussels act as highly significant ecosystem engineers. In addition to their natural abundance in wild populations, Mytilus spp. also comprise a major sector of UK aquaculture production, second only to salmon in tonnes produced each year by weight. A spectrum of strains and hybrids exists across three Mytilus species: Mytilus edulis, M. trossulus and M. galloprovincialis. Previous research has shown that mussel aquaculture has an effect on the distribution of these hybrids throughout the UK, although very little is known on the implications that hybrid genetics may have on the inherent biology of this keystone species. Facing increasing stress from ocean acidification, rising temperatures and altered salinity profiles, the challenge of dealing with pathogenic and environmental assault will become a growing concern for wild and farmed mussel populations.

Building on previous efforts to map the admixture of mussel hybrids around the UK, this project will investigate allelic inheritance patterns and innate immune profiles across hybrids. Using available reference genomes and genotyped hybrid population data, the applicant will define the immune gene repertoire across different Mytilus subspecies and predict inheritance patterns of these genes across hybrids. These predictions will be tested using field-sampled individuals. Disease and environmental stress will be developed to investigate the extent of potential deleterious or beneficial effects of hybridisation. This will be achieved by combining traditional biology and cutting-edge molecular biology based tools including gene-expression techniques.

The Roslin Institute is a world-leading centre for aquaculture science and genetics and the successful candidate will be welcomed into a growing team of researchers studying disease and genetics in aquaculture. The student will be expected to travel nationally and internationally and work effectively in laboratory and field settings. The applicant will have a keen interest in aquaculture science, environmental science, and pathogen biology. This project will require skills in fieldwork, bioinformatics, population genetics and molecular and cell biology techniques. Training will be provided for the right candidate, but experience in some or all of these areas is desirable.

Research questions

1. How do different Mytilus species differ in their innate immune sensing/signalling gene repertoires?

1. How does hybridisation affect inheritance of these genes?

1. What effect does hybridisation have on the ability of mussels to respond to environmental and pathogenic stress?

1. Can we predict potential risks for wild population genetics?

1. What additional efforts should mussel hatcheries focus on to safeguard stocks?

Methodology

Applying bioinformatics, field work and molecular biology techniques, the successful applicant will study the repertoire of immune genes across Mytilus supspecies and examine the effect hybridisation has on the expression and function of these genes. 

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• Year 1 
• Bioinformatics analysis of available reference genomes for Mytilus subspecies. Comparing diversity of innate immune sensing/signalling genes. Predicting the inheritance of these genes during hybridisation using available genotyping data of hybridised populations.

• Year 2 
• Field sampling of hybridised individuals. Spawning single species mussels, growing spat from these animals. Recovering DNA of offspring and parent animals for genotyping. Development of in vivo and ex vivo pathogen and environmental stressor challenge systems.

• Year 3 
• Expression patterns of stress and innate immune response genes will be assessed through RNAseq of adult haemocytes under induced pathogenic and environmental challenges in vitro. Examine how do blue mussel subspecies influence allelic inheritance patterns. Investigate whether transcriptional stress responses are significantly affected by mussel hybridisation. Disseminate results from analyses through international meetings and three publications.

Training

A comprehensive training programme will be provided comprising both specialist scientific training and generic transferable and professional skills.

Field working near to water. Bivalve mollusc handling, spawning, and culture in laboratory scenarios.

Standard molecular biology techniques including DNA and RNA extractions, PCR, qPCR, cloning, DNA and RNA sequencing library preparation.

Bioinformatics of reference genome assemblies and imputation of allelic inheritance using genotyping data, RNAseq.

Engaging with industry and the public to disseminate findings.

Requirements

Field work, bivalve culture, molecular biology, genomic analyses, coding, writing scientific literature.

References

Robert P. Ellis, Steve Widdicombe, Helen Parry, Thomas H. Hutchinson, John I. Spicer. Pathogenic challenge reveals immune trade-off in mussels exposed to reduced seawater pH and increased temperature. J. Exp. Mar. Biol. Ecol. 2015; 462: 83-89 https://doi.org/10.1016/j.jembe.2014.10.015

Ellis RP, Spicer JI, Byrne JJ, Sommer U, Viant MR, White DA, Widdicombe S. (1)H NMR metabolomics reveals contrasting response by male and female mussels exposed to reduced seawater pH, increased temperature, and a pathogen. Environ Sci Technol. 2014 Jun 17;48(12):7044-52. https://doi.org/10.1021/es501601w PMID: 24846475.

Michalek, K, Vendrami, DLJ, Bekaert, M, Green, DH, Last, KS, Telesca, L, Wilding, TA & Hoffman, JI. Mytilus trossulus introgression and consequences for shell traits in longline cultivated mussels. Evol Appl. 2021; 14: 1830– 1843. https://doi.org/10.1111/eva.13245

Supervisors

Tim Bean

Roslin

[email protected]

www.ed.ac.uk/roslin/aquaculture/people/tim-bean-gl

Tim Regan

Roslin

[email protected]

www.ed.ac.uk/roslin/aquaculture/people/tim-regan

Robert Ellis

University of Exeter

[email protected]

biosciences.exeter.ac.uk/staff/profile/index.php?web_id=Robert_Ellis

E4 supervisors are happy to hear from candidates who would wish to adapt the project to their own ideas and research background.

How to Apply

Please find all relevant information, application forms and instructions for referees via -

https://www.ed.ac.uk/e4-dtp/how-to-apply/application-process