The Toxopeus lab focuses on understanding how animals and their cells survive in challenging environments. This is important for understanding how organisms tolerate current environmental stressors, and how they might respond to future changes in their environment (e.g. due to global climate change). We use an integrative approach to answer questions about stress tolerance, employing molecular biology (e.g. qPCR), cell biology (e.g. confocal microscopy), bioinformatics (e.g. transcriptomics, metabolomics), functional genetics (e.g. RNA interference) and whole animal physiology.
Specifically, our lab focuses on how insects protect their cells at low temperatures (including when they are frozen!), and how this affects their overwintering success. For details on our research projects, read on!
The Challenges of Freezing
Remarkably, some insect species survive freezing, including the spring field cricket (Gryllus veletis). We assume that internal ice formation is challenging, but we don’t know much about how it harms organisms at the cellular level. We use G. veletis as a model to study how low temperatures and freezing damage cells, testing the hypotheses in the graphical summary below.
Interested in learning more? Read this review about insect freeze tolerance.
The Cell Biology of Freeze Tolerance Acclimation
The spring field cricket (Gryllus veletis) becomes freeze-tolerant in the Fall, allowing it to survive internal ice formation. We know that acclimation to Fall conditions (i.e. low temperatures and short days) is required for freeze tolerance in this species. However, we know little about the cellular changes that occur during acclimation, which could protect against the challenges associated with freezing. We use G. veletis as a model to study how animals might modify their cell biology to promote freeze tolerance, testing the hypotheses in the graphical summary below.
The Biochemistry and Genetics of Freeze Tolerance
The spring field cricket (Gryllus veletis) substantially alters its gene expression and metabolite composition when it becomes freeze-tolerant, and previous work has suggested that several genes and small molecules (e.g. cryoprotectants) are important for surviving freezing. We use methods to manipulate gene expression (e.g. RNA interference) and metabolite concentrations in these crickets to test their function in freeze tolerance – both for survival of the whole animal and its cells.