Our research is focused on illuminating the role of genomic parasites in generating intragenomic conflict, predominantly working with insects, by elucidating the consequences for mating systems, the evolution of new traits, the creation of biological novelty, and the survival of populations. We pose our questions in the context of intense insecticide usage in agriculture and environmental stresses caused by climate change.
Selfish genetic elements and sexual selection
Selfish genetic elements (SGEs) such as transposable elements, segregation distorters, and maternally inherited symbionts are found in all organisms and can cause reproductive incompatibilities, feminisation, and male deaths that distort the sex ratio. Females may mate multiple times to promote sperm competition and avoid fertilisation by SGE-carrying sperm. We examine the impact of SGEs on male fertility in flies and the impact of sex-ratio-distorting endosymbionts for the expression of male sexually selected traits in butterflies.
Sexually antagonistic (SA) alleles
Genetic variation in wild populations is higher than expected. How such variation is maintained is a key question in evolutionary biology. Sexually antagonistic (SA) alleles are genes expressed in both sexes that are advantageous to one sex but detrimental to the other. We study SA alleles in butterflies, moths, and flies. In fruit flies (Drosophila melanogaster), a transposable element (TE) inserted into the metabolic gene (Cyp6g1) confers insecticide resistance and increases female fecundity, but can decrease male mating success and alter male aggression. TE insertions and Cyp6g1 duplications are associated with sex differences in resistance. We investigate the impact of multiple TE insertions on resistance evolution and their potential SA effects. We also interrogate the molecular mechanisms responsible for SA, trying to understand how the same allele can lead to contrasting sexual effects between males and females. While examining the importance of these elements as evolutionary forces we also investigate their effect considering anthropomorphic, abiotic, and biotic factors that pose a threat to insect populations, such as insecticide usage and climate change.
Hidden conflict between sexes maintains genetic diversity
Contact
For enquiries, please email Prof Nina Wedell - nina.wedell@unimelb.edu.au
Meet the academics and researchers in the Wedell Lab.
Research group members
Dr Andre Nogueira Alves
Andre is a Research Fellow in the Wedell lab where he focuses on the evolutionary and genetic basis of insecticide resistance and sexual conflict. He completed his MSc in Universidade de Lisboa, Portugal, where he researched how novel species adapt to new nutritional environments, and how organ growth and patterning are coordinated. After, he pursued a PhD at Monash University under the supervision of A/Prof. Christen Mirth, A/Prof. Matt Piper and Prof. Carla Sgr, focusing on the effects of protein in nutritional plasticity in female fecundity. He joined Prof. Damian Dowling’s lab to collaborate on a research project looking at the effect of mito-nuclear backgrounds on the severity of the mother’s curse before joining the Wedell lab. He is currently focused on understanding how evolution in insecticide resistance genes shapes variation in populations. He also looks into how nutrition can impact insecticide resistance as a means to enhance it or deter it. Finally, he is also
andre.nogueiraalves@unimelb.edu.au
Dr Jonathan Wilson
I am a bioinformatician and population geneticist primarily interested in the genomic basis of rapid adaptation. My PhD research focused on how structural variants (namely chromosomal inversions and copy number variation) contribute to the success of the invasive common ragweed, Ambrosia artemisiifolia. I am now working on understanding how transposable elements (TEs) may facilitate rapid adaptation, alongside how they may also prevent adaptive variants from spreading between populations. Focussing on Drosophila melanogaster as a model, I am using both genomic data and experimental evidence to unravel the fascinating world of TEs, and further our understanding of their importance in evolution within short timescales.
jonathan.r.wilson@unimelb.edu.au
David Sanchez Rodriguez
David is a biologist who graduated from the University of Quindío (Colombia, 2021) with a strong commitment to understanding and biodiversity. During his undergrad research, he examined the population status of red howler monkeys, Alouatta seniculus, in a protected area in the heart of the tropical Andes, gaining valuable field experience and skills in biological data analysis. In 2024, he joined the Wedell Lab as a master’s student, where he is investigating the molecular pathways that may reveal the evolutionary responses of insect populations to rising temperatures and chronic exposure to agrochemicals. His research uses the non-pest insect model vinegar fly, Drosophila melanogaster.
d.sanchezrodriguez@unimelb.edu.au
Krzysztof Janowicz
I graduated from the University of Aberdeen with a MSc in Genetics with specialisation in immunology. As part of my Bachelor degree I completed a yearlong research placement under the supervision of Prof. Bartosz Kempisty at Poznan University of Medical Sciences, where I conducted an individually designed project on the role of exosomes in tongue cancer. During that time, with three other students sent from Aberdeen, I also co-authored 14 publications, both original papers and systematic reviews. My master thesis was completed under the supervision of Dr Catriona Cunningham. The thesis was a meta-analysis and systematic review on the role of gene therapies in the process of regenerating injured spinal cord. It was the very first analysis alike ever conducted for the injury of the spinal cord and got published on the account of the University of Aberdeen. I have also visited Wuhan University due to my interest in Mandarin and completed an Erasmus Exchange at University College Cork.
Research in the Wedell group: Evolutionary Insect Lab.
Student lab projects
The effect of individual amino acids in insecticide resistance
This project investigates the relationship between nutrition and toxicology. Previous research shows that feeding D. melanogaster with food lacking one essential amino acid (EAA) improves resistance to nicotine. This suggests that diets can affect an individual’s tolerance to xenobiotics. We aim to assess how the presence of an insecticide resistance gene (Cyp6g1) correlates with insecticide sensibility when flies are reared on different nutritional environments. In short, flies with different Cyp6g1 resistant alleles will be fed diets lacking different single EAA for varied periods of time and assessed for fertility, longevity, and insecticide resistance.
The effect of transposable elements on fertility
Cyp6g1 is an important locus that confers resistance to multiple insecticides. An allelic series for this locus exist, with each allele conferring different levels of insecticide resistance. Importantly, different alleles also affect fly fitness, but in opposite ways - increasing female but reducing male fitness. This project aims to understand how the presence of a P-element in the Cyp6g1 BP allele can affect the female (and possibly male) fertility. P-elements are known to profoundly affect Drosophila fertility through hybrid dysgenesis. Flies with BP alleles in different genetic backgrounds will be assessed for dysgenic phenotypes in females (ovary atrophy). Using molecular techniques, the P-elements will be characterised to investigate their activity and contribution to the dysgenic phenotype.
The role of a sexually dimorphic gene in insecticide resistance
Cyp6g1 is an important locus that confers resistance to multiple insecticides. An allelic series for this locus exist, with each allele conferring different levels of insecticide resistance. Importantly, different alleles also affect fly fitness, but at times in opposite ways - increasing female but reducing male fitness. We aim to interrogate the molecular mechanisms responsible for these sex-specific effects. Using molecular biology and tissue-specific genetic drivers this project aims to investigate how the sex-specific expression patterns of the different Cyp6g1 alleles in larval and adult tissues contribute to behavioural differences and fitness phenotypes.
Evolution of allelic polymorphisms in natural populations exposed to climate change
Natural populations are locally adapted to specific conditions. However, climate change is altering these conditions at an alarming rate. The effect of changing temperatures on natural variation is an emerging field of study with great importance. We propose to study how natural variation in Cyp6g1 allelic polymorphism, a gene responsible for conferring resistance to insecticides, change between populations that are locally adapted when exposed to new temperatures. Allelic frequencies of populations from north and south of the East coast of Australia will be assessed over multiple generations when exposed to different temperature ranges to quantify the contribution of each allele to temperature sensitivity. The temperature ranges will also be assessed for impacts on fitness and behaviour.
The synergism between temperature and insecticides for the demise of insect population
Insect population numbers are plummeting globally. Two important factors that may contribute to this ecological catastrophe are climate change and intense insecticide usage in agriculture. Using different mutant and wild-type Drosophila strains (sensitive or resistant to insecticides) this project aims to investigate how temperature and insecticides synergise. The tolerance to insecticide in males and females of different genetic backgrounds will be tested when flies are reared at different temperatures. Impacts on fitness and neurodegeneration (climbing ability and bang-sensitivity) will be assessed as well as the rescuing ability of antioxidants.