Research
Future directions
The Van der Burg lab will investigate how environmental cues are translated into different internal endocrine signals.
Hormone signaling must change in response to environmental conditions, while also avoiding pleiotropic effects on fundamental developmental processes. Some of the neuroendocrine molecules driving change in regular ecdysone signaling are well known, but it is unclear how these molecules change in response to seasonal conditions. Also unclear are the developmental genetic mechanisms interacting with these physiological signaling pathways, and how these mechanisms could evolve. We will investigate (1) how signaling molecules vary between different seasonal conditions, and (2) how these molecules interact with the gene regulatory landscape in different developmental stages. Lastly, we will (3) investigate whether evolution acts directly on the ecdysone signaling pathway. The combination of physiology, gene regulation and evolution is a particular powerful method to investigate how seasonal conditions are integrated into internal regulatory mechanisms, and I will be able to provide a complete characterization of the fitness optimization process under different seasons.
Seasons change throughout the year, and different conditions will require different fitness strategies. We investigate the genetic and physiological mechanisms underlying fitness optimization strategies in different seasons. Take a look below for some past and current research projects!
Genomic architecture of a genetically assimilated seasonal color pattern
The Common Buckeye butterfly, Junonia coenia, develops a pale tan color when reared under warm, long-day conditions, and a dark red color when reared under cold, short-day conditions. This wing color plasticity also rapidly evolves to always have the same phenotype, regardless of conditions. We investigated the genetic basis of variation in wing color plasticity, and found three genetic loci to cause changes in phenotypic plasticity. (Science, 2020).
We proposed that seasonal plasticity could evolve through small changes in downstream effectors of endocrine cues, which allows for more tissue specific tuning while avoiding pleiotropic effects caused by changes in hormone signaling. We hypothesized that seasonally plastic phenotypes could be regulated through ecdysone mediated changes in the chromatin landscape. (Current Opinions 2021)
The Genetics of winter adaptation in a boreal forest pest
Insects living in temperate climates often enter a state of dormancy to survive harsh winters. This so-called diapause is associated with large changes in physiology and development. Decades of research have uncovered physiological, transcriptional, and genetic changes associated with diapause, yet a true integrative approach is still lacking. Also not well understood is how these mechanisms underlying the diapause phenotype are regulated, and how natural selection acts on these regulatory mechanisms.
Future directions
The Van der Burg lab will (1) characterize the physiological, transcriptomic and chromatin landscape changes that differentiate diapausing and non-diapausing spruce budworm, (2) determine the genetic basis of this change in the diapause phenotype, and (3) investigate how natural selection acts on the diapause specific regulatory landscape across the range.
This would be the first study that integrates across multiple science disciplines including physiology, functional genomics, genetic mapping and population genetics to provide a complete characterization of the diapause phenotype. Results from this study will allow us to understand how fitness is optimized under extreme seasonal conditions, and how these fitness optimization methods evolved.