Primary Supervisor – Professor Tracey Chapman

Strong interdisciplinary training, within the ARIES theme Environment and Biodiversity, to equip you with highly in-demand analytical skills in phenotypic and molecular genetic engineering.

Scientific background

In all species that lay eggs externally – in nests, ponds, mounds of mud, food, or other substrates – eggs and young may face unpredictable exposure to harmful or beneficial microbes. Mothers may manipulate the immediate microbial environment by providing eggs with protective antimicrobial compounds. One obscure example—the focus here—occurs in a global agricultural pest, the Mediterranean fly (Ceratitis capitata). Medfly mothers coat their eggs with powerful, broad-spectrum antimicrobial peptides that include four “ceratotoxins” encoded by 7 genes. These kill microbes by creating holes in them. Offspring from eggs lacking protective antimicrobials grow slower, giving the first insight into potential benefits and providing a starting point for you to use phenotypic engineering, sequencing and gene editing tools to determine:

(i) Inclusive fitness benefits of serotoxin egg coats under natural conditions

(2) Functional significance of ceratotoxin repeats

(3) Potential of ceratotoxins for insect control

methodology

(i) Benefits of physical fitness

Testing the main hypotheses of protective egg cloaks:

• Protecting eggs and larvae from harmful microbes
• Protecting the female reproductive system from sexually transmitted diseases
• Creating a beneficial microbial community for larvae and eggs
• Facilitating the vertical transmission of beneficial microbes

Assays of key fitness measures (survival, fecundity, near-natural conditions) using phenotypic manipulation (egg mantle removal, microbial additions), sequencing (16S rDNA of microbial communities) and molecular genetics (CRISPR-Cas9 knockouts of ceratotoxin gene clusters).

(2) Functional redundancy

To determine whether seratotoxin duplication is adaptive: (1) test the antimicrobial spectrum and efficacy of synthetic seratotoxin peptide mixtures, (2) examine key fitness metrics of gene-edited Mediterranean flies lacking seratotoxin.

(iii) Pest control

Depending on interests, explore (by experimentation, modeling, or quantitative literature synthesis) different possibilities for using ceratotoxin in insect control, including engineering solutions to reduce host fitness, or to improve the health of strains bred in large quantities for sterile release.

an exercise

Highly in-demand technical skills (bioinformatics, molecular genetics, microbiology, phenotypic engineering) and transferable skills (critical thinking, ethics, open research). Embedded in a thriving, respectful and inclusive research environment.

Person specifications

Suitable for the individual interested in addressing questions of fundamental importance with applied potential for controlling insects that threaten food security.

Entry requirements

At least a UK BA (Hons) equivalency of 2:1. English language requirements (Faculty of Science equivalent: IELTS 6.5 overall, 6 in each category).

Acceptable first degree: Biological Sciences, Genetics, Ecology.

Study method: Full or part time

Start date: October 1, 2026

Additional financing information

ARIES Scholarships are governed by UKRITerms and Conditions. Successful candidates who meet UKRI’s eligibility criteria will be awarded a fully-funded scholarship, which covers fees, a maintenance stipend (£20,780 per annum for 2025/26) and a Research Training and Support Grant (RTSG). A limited number of scholarships are available to international applicants, with the difference between ‘national’ and ‘international’ fees waived by the registered university. However, please note that ARIES funding does not cover additional costs associated with moving to and living in the UK, such as visa costs or additional health fees.