Weekly PhD Newsletter | SIGN UP NOW Weekly PhD Newsletter | SIGN UP NOW

Genomic mechanisms and eco-evolutionary dynamics under stressful and changing environments


   School of Biosciences

This project is no longer listed on FindAPhD.com and may not be available.

Click here to search FindAPhD.com for PhD studentship opportunities
  Dr Juliano Sarmento Cabral, Dr M Catoni  No more applications being accepted  Competition Funded PhD Project (Students Worldwide)

About the Project

General background: Genomes may vary in DNA content (e.g. amplification of repeated sequences) or in chromosomes (e.g. dysploidy or polyploidy), which can bear adaptive value. In fact, the increase in DNA content and ascending dysploidy may decrease gene linkage, affect gene regulation or repurpose the extra copies. Genomic processes may occur at higher rates under stressful conditions. For example, plant individuals at their niche borders have a higher production rate of unreduced gametes, promoting autopolyploidization. However, it is little understood how different genomic processes interact and how adaptive are the resulting genomic variants to population and species survival. Shedding light to these gaps will unravel how species may respond to impending environmental change, which will likely trigger genomic variants.

Objectives: To assess how variation in DNA content and chromosome number affect eco-evolutionary processes under stressful, changing environmental conditions. Specifically, the project will address 1) whether an increase in DNA content increases individual fitness, population persistence and species survival, caused at random or at specific areas 1.1) of the genome and 1.2) of the species’ range distribution; 2) whether autopolyploidy has similar effects; 3) whether variation of DNA content and chromosome number have synergetic effects when triggered together; 4) identify species more vs. less likely 4.1) to undergo these adaptive processes and 4.2) to respond to ongoing environmental change via genomic variants.

Methods: This project takes a mechanistic eco-evolutionary approach by applying the first genomically-explicit mechanistic model (GeMM - Leidinger et al. 2021) to a study system showing high DNA content and chromosomal variation – the Maxillariinae orchids (Moraes et al. 2022). Maxillariinae orchids are a horticulturally relevant group (e.g. Bifrenaria, Lycaste, Maxillaria). The GeMM simulates in a spatially explicit environmental arena diploid plant individuals competing for space and performing life-history processes (growth, reproduction, dispersal, survival). These processes are controlled by genomically coded parameters. The genome contains coding and non-coding base pair sequences and undergoes mutation and recombination during gametogenesis. The number of genes per ecological traits and level of gene linkage is hitherto species-specific. Individual fitness (the match between environmental preferences and local conditions), population persistence and species survival emerge from simulation experiments. The project will extend GeMM to integrate intraspecific variation in DNA content and chromosome number (first two years). The objectives 1-3 will be tackled via experiments varying i) DNA increase across the genome (2nd year); ii) changes in chromosome number (3rd year); iii) both processes together (4th year). The environmental preferences will be given by distribution models of species for which we have DNA content, chromosome number and phylogenetic relationship (Moraes et al. 2022). Ecological traits will be assembled in collaboration with Prof. Moraes. Simulation experiments will explore current or estimated ancestral traits. Emergent distribution ranges as well as genomic properties will be statistically parameterized to real-world data to estimate the rate of each genomic process (e.g. DEoptim R package). Parameterized species will have their genetic and ecological trait combinations compared and will be simulated under environmental change to address objective 4.


Funding Notes

Projects are open to both home and International students (EU students are now classed as international). BBSRC have indicated that up to 30% of the cohort are allowed to be international students.
UoB are waiving International Fees, however international students will still have to pay for their own visas and a healthcare surcharge which is approximately £2500.

References


Leidinger L, Vedder D & Cabral JS 2021 Temporal environmental variation may impose differential selection on both genomic and ecological traits. Oikos 130: 1100-1115.
Moraes AP, Engel TBJ, Forni-Martins ER, de Barros F, Felix LP & Cabral JS 2022 Are chromosome number and genome size associated with habit and environmental niche variables? Insights from the Neotropical orchids. Ann Bot 130: 11-25.

How good is research at University of Birmingham in Biological Sciences?


Research output data provided by the Research Excellence Framework (REF)

Click here to see the results for all UK universities
Search Suggestions
Search suggestions

Based on your current searches we recommend the following search filters.

PhD saved successfully
View saved PhDs