As T. Dobzhansky famously said: ”nothing in biology makes sense except in the light of evolution”. Making sense of biology in the light of evolution can be especially relevant for species that are important for human health, as insights here can contribute towards the re-thinking of new strategies for disease mitigation or to predict how a species will resist current strategies. We are interested in combining computational biology with new omic technologies to address some of these questions.
Y chromosomes - evolution and function
Because Y chromosomes of most species are highly heterochromatic and repeat rich, they are generally resistant to genome sequencing and assembly efforts. For example, Anopheles Y chromosomes have been completely a black box for more than a decade since the first genome sequencing project was completed. To overcome this problem, we are leveraging a number of genome sequencing technologies with tailored computational methods to unwrap the content and evolutionary history of the Y. We have recently shown this can work by completing the primary discovery and exploration process for the Y chromosomes of a group of malaria mosquitoes in the gambiae complex . We have shown that their Y chromosomes are mainly composed of a handful of repetitive elements that have become massively amplified and vary dramatically between closely related species and even within a population. We have also catalogued the genes present of the Y and identified one of these as the likely sex determiner (which was subsequently functionally confirmed) and a possible male fertility gene. Our efforts are far from complete. A complete assembly is still unattainable using current methods and sequencing technologies. Our long term goal is to build the first fully completed Y chromosome assembly and to describe the functions of the loci that are on it.
Evolution of the sexes
Apart from the sex-limited Y chromosomes that are gene poor and small, males and females share a common genome. We are exploring how this shared genome generates the significant sexual dimorphism between the sexes and how these differences express themselves evolutionarily of the genomic landscape of mosquitoes. The aim of our work is to characterize the evolutionary properties of sex-biased genes and to understand what and how these forces are shaping mosquito biology.
We are involved in a number of efforts to build or improve reference genome assemblies for a number of insect species. We have contributed in 16 Anopheles Genome Project and the European Albopictus Genome consortium. We are currently running Albo2.0 to improve the reference assembly of the tiger mosquito using new sequencing technologies.