Trajectories of genome evolution in convergently evolving insect lineages
Organisms often evolve similar adaptations to similar environments in the process of convergent evolution, indicating that the trajectory of phenotypic evolution is amenable to predictions. Whether the genomic trajectories of convergent organisms are parallel - and thus predictable in principle - is unclear due to the scarcity of genomic evidence from convergent organismal groups. To answer these questions, we are using a model system consisting of rove beetles (Staphylinidae) and scuttle flies (Phoridae) that adapted more than twenty times repeatedly to live in symbiosis with termites. Using phylogenetics, comparative genomics, transcriptomics, and microtomographic reconstructions of phenotypes, we will infer the extent, the timescale, and the hierarchical level of genome sequence evolution at which parallel patterns of genome evolution accompany the evolution of convergent adaptations.
Research in collaboration with Tom Bourguignon (OIST, Japan) and Taisuke Kanao (Yamagata University, Japan).
Funding: 5-year research grant JUNIOR STAR GAČR from the Czech Science Foundation(25M CZK ~ 1M EUR, 2023-2027).
Termite phylogenetics
Termites with ~ 3,100 described species represent a modestly diverse group which, however, reached a global ecological impact during the estimated ~ 140 millions of years since the inferred diversification of the last common ancestor of all living termite species. To reconstruct the diversification of termite lineages we built phylogenetic hypothesis using a range of molecular genetic markers, including mitochondrial genomes, nuclear protein-coding gene orthologs, and nuclear ultra conserved elements. These backbone phylogenetic trees allowed us then to infer the shifts in symbiotic relationships within termite guts (Buček et al. 2019), or the historical biogeography of termites and their dispersal potential (Buček et al. 2022, Wang et al. 2019, Wang et al. 2022).
Research started in the lab of Tom Bourguignon (OIST, Japan) and Jan Šobotník (CULS, Czechia).
Evolution of defense in termites
One of the likely key adaptations that led to the evolutionary success of termites is defense. While some termite workers evolved remarkable self-sacrificial chemical defensive strategies, the principal termite colony caste responsible for active defense are the soldiers. Termite soldiers typically combine their capacity to produce chemical secretions (Jirošová et al. 2017, Bourguignon et al. 2016) and mechanical weapons in the form of their mandibles (Beránková et al. 2022). One remarkable mandibular defense strategy - so called mandibular snapping - presumably evolved many times independently in termites. In this strategy, soldiers of some termite species evolved mandibles that lost the biting ability and instead adapted into springs that can deliver a lethal strike to insect competitors of termites. Remarkably, this highly derived mandibular strategy apparently evolved multiple times convergently. Currently, we are conducting a comparative evolutionary study across termite lineages to uncover the evolutionary trajectories that lead to mandibular snapping.
Research started in the labs of Tom Bourguignon (OIST, Japan) and Jan Šobotník (CULS, Czechia).
Evolution of pheromone communication
Pheromones mediating communication within individuals of the same species represent an experimentally traceable chemical analog of human language. We studied the evolution of inter-sexual pheromone communication in moths (Manduca sexta) and bumblebees (Bombus sp.) from the perspective of pheromone producers using a combination of chemical analysis and molecular biology methods. We analyzed transcriptomes of pheromone glands, uncovered repertoires of pheromone biosynthetic enzymes, their expression levels, enzymatic selectivities, and their evolvability during in vitro mutational screening. We demonstrated how genetic mechanisms such as gene family expansion, expression regulation, and mutation in the protein-coding portion of genes lead to shifts in the spectrum of biosynthetic capacities of pheromone biosynthetic pathways. For more details, see our papers on evolution of pheromone biosynthesis (Buček, Matoušková et al. 2015, Buček et al. 2016, Prchalová, Buček et al. 2016, Tupec, Buček et al. 2017, Tupec, Buček et al. 2019, Buček et al. 2020)
Research conducted in the lab of Iva Pichová (IOCB, Czechia) in close collaboration with Irena Valterová (formerly IOCB, Czechia) and Aleš Svatoš (formerly at Max Planck Institute for Chemical ecology, Germany).