Evolutionary and ecological consequences of genetic sex determination

Project: Dissertation

Project Details

Description

My doctoral studies will focus on the evolutionary and ecological consequences of genetic sex determination. I will focus on the systems (i) Sylvioidea birds and (ii) bumblebees:

i) Sex chromosomes are believed to evolve when an autosome gains a sex determining mutation, which in turn favours linkage of other sex-specific genes around that locus. With time recombination is suppressed in the heterogametic sex to ensure that these sex related genes are inherited together. Over time, sex chromosomes take on some characteristics such as degeneration and gene loss through accumulation of deleterious mutations on the sex-limited chromosome (Y or W), and dosage compensation in the heterogametic sex. In the passerine superfamily Sylvioidea there have recently been several neo-sex chromosomes discovered, some which are shared by all families, some which are unique to a few families, within Sylvioidea. The time range of these chromosome fusions provides me with a system to study several steps in sex chromosomes evolution in relation to demography, sexual selection, and environmental adaptations.

ii) In haplodiploid Hymenopteran, females are diploid and develop from fertilised eggs, while males are haploid and develop from unfertilised eggs. Sex determination in itself is believed to be caused through complementary sex determination at the CSD locus. Heterozygotes at this locus become female, while homozygous diploids and hemizygotes become male. A fitness benefit of this system should be resilience to inbreeding depression as recessive deleterious alleles may be purged through expression in the haploid male. However, reduced allelic diversity at the CSD locus could result in involuntary production of diploid homozygous males that do not contribute resources to the colony, therefore reducing its fitness. While the CSD locus is well characterised in the honeybee, it is not yet so in bumblebees. In my studies I will try to locate and describe the CSD locus in bumblebees, as well as study it in relation to population health. I will approach this topic through studies of wild populations of bumblebees and through demographic modelling, with the aim to further improve conservation efforts of declining, wild bumblebee populations.
StatusActive
Effective start/end date2021/02/01 → …

UN Sustainable Development Goals

In 2015, UN member states agreed to 17 global Sustainable Development Goals (SDGs) to end poverty, protect the planet and ensure prosperity for all. This project contributes towards the following SDG(s):

  • SDG 15 - Life on Land

UKÄ subject classification

  • Evolutionary Biology
  • Genetics
  • Ecology