Speciation by genetic conflict

Description

Aim: to determine whether selfish chromosomes that kill sperm create reproductive isolation

How new species form is a major question in biology. Key to this is reproductive isolation- the factors that prevent two populations interbreeding. Traditionally, ecological differences between populations have been thought to create reproductive isolation. But recently, a new theory has arisen that conflict within the genome drives speciation.

Many species harbour selfish genetic elements that spread by manipulating reproduction. For example, some X chromosomes kill Y chromosome sperm, so all offspring inherit the driving X, and all offspring are female. These selfish elements create intense conflict over reproduction, as the driver evolves to drive more effectively, and the rest of the genome evolves mechanisms to stop it. This intragenomic conflict rapidly alters genes involved in making gametes in population that carry the selfish genetic elements.

One key prediction of conflictual speciation theory is that selfish genetic elements will be adapted to their local population, and will perform poorly in hybrids. When a driver enters a naïve population with no defences against drive, the drive is expected to attack too strongly, sterilising hybrids. So drive will not be able to spread between species. However, it is possible that this is wrong, and instead drivers will spread rapidly through naïve populations and species, potentially homogenising them.

In this project you will investigate how selfish meiotic drivers interact with hybridisation. We will use a suite of meiotic drive systems in various Drosophila species. We will first cross each species to closely related species to establish which can hybridise. We will then repeat the crosses with individuals bearing meiotic drive chromosomes. Can drivers spread rapidly through naïve species, having a homogenising effect? Or will the cost of drivers kill or sterilise drive-bearing hybrids?

HOW TO APPLY

Notes and details of how to apply are available here: https://accedtp.ac.uk/acce-dtp-phd-opportunities-at-university-of-liverpool/

All applicants to ACCE must complete the ACCE personal statement proforma. This is instead of a normal personal/supporting statement/cover letter. The proforma is designed to standardise this part of the application to minimise the difference between those who are given support and those who are not.

The ACCE DTP is committed to recruiting extraordinary future scientists regardless of age, ethnicity, gender, gender identity, disability, sexual orientation or career pathway to date. We understand that commitment and excellence can be shown in many ways and have built our recruitment process to reflect this. We welcome applicants from all backgrounds, particularly those underrepresented in science, who have curiosity, creativity and a drive to learn new skills.

Informal enquiries may be made to tarp201@liverpoool.ac.uk.