CBA-supported Honours/Masters project (2018/9)
This project will use data from Australian pest moth populations that have been subjected to severe selective pressure, in the form of insecticide resistance, through time.
Based on the premise that telomeres (chromosome ends) are expected to get shorter as environmental stress increases, we aim to use telomere length as a biomarker for stress in pre- and post-insecticide pest populations.
Specifically, we expect to see a shortening of telomere length in stressed (post-insecticide) vs. non-stressed (pre-insecticide) populations.
The successful student will work using a bioinformatic pipeline to examine telomere lengths in full genome re-sequencing data. They will receive a generous $5,000 stipend, along with excellent support throughout the project.
The project presents an exciting opportunity to work between the Research School of Biology (RSB) at ANU and CSIRO Black Mountain laboratories with project supervisors Dr Angela McGaughran (Ecology & Evolution, RSB) and Dr Kerensa Mcelroy (Agriculture and Food Flagship, CSIRO).
Telomeres are 'caps' that sit at the end of chromosomes and have been likened to the plastic tips that cover shoelaces because of their protective role in preventing chromosomes from unravelling. Essentially, they are repetitive nucleotide sequences that stablise chromosome ends and prevent them from being recognised as DNA double strand breaks.
Because they block the ends of chromosomes, telomeres prevent cells from fully replicating the ends of linear chromosomes and, as a result, telomeres get shorter in length with each round of cell division/replication. Thus, telomere attrition is associated with normal cellular aging and, in humans, we know that it can actually be causal in the acquisition of age-related diseases.
In recent years, researchers have shown an association between telomere length and chronic stress, with adverse social and environmental influences significantly related to shorter telomere lengths in both human children and adults. This leads to the potential for telomere length to be a biomarker for stress in different species.
This project will use a temporal series of samples of the Australian pest moth, Helicoverpa armigera (the Cotton Bollworm). These samples span a time frame that includes pre-1950s samples collected in Australia before insecticides were first used, as well as samples that were collected during the 1970s-1980s when populations were exposed to insecticides.
Thus, the first set of samples serve as a 'pre-stress' time-point, while the second set correspond to 'stressed historical samples'. In addition to historical DNA, published whole genome sequencing data exists for Australian H. armigera that were collected in the last 10 years. These latter samples were collected from populations that have not been exposed to the insecticides that were being applied in Australia in the 1970s-1980s, thus can be considered to be 'post-stress contemporary samples'.