Hafen lab: Master’s thesis and/or semester project on the role of cryptic genetic variation on circadian behaviors
Cryptic genetic variation (CGV) is the hidden genetic variation accumulated over time that do not contribute to the normal range of phenotypes, but may provide a source of adaptive variation to novel conditions. This project will examine if the CGV in different genetic backgrounds is influential in the evolution of circadian traits. (Keywords: Drosophila melanogaster, genetics, behavior, circadian rhythms)
Organisms constantly adapt and evolve in response to internal and external stimuli. Changes can arise by either new mutations or by pre-existing genetic variation in the system. The latter standing genetic variation, which does not affect the usual range of phenotypes, but can potentially modify a phenotype in the event of an environmental (e.g. diet, temperature, pollution) or genetic (e.g. new mutations) perturbation, is cryptic genetic variation [1]. The uncovering of CGV due to the environmental and cultural changes in recent human history could be an explanation for the rising incidences of “diseases of modernity” (e.g. lung cancer, asthma, diabetes) [2]. CGV has also been implicated in climate change adaptation in a number of organisms.
CGV has also been implicated in modern mental health diseases such as depression, schizophrenia, and bipolar disorder [2], but evidence supporting CGV’s impact on behaviors is limited. Aberrations in circadian rhythms are linked with many of these mental illnesses as well as in drug addiction. In this project, we will be perturbing the period gene, which is a well-studied gene in the circadian cycle, in a panel of Drosophila melanogaster inbred lines derived from a natural population, to see how the genetic backgrounds of these different lines are influential in how each line reacts to the genetic perturbation.
We are looking for one or two highly motivated, responsible individuals who are critical thinkers to help with this project. By working on this project, students will learn how to search for and read scientific literature, basic fly husbandry, genetic manipulations, circadian behavior assaying, basic statistical data analysis, and more. Semester projects or Master’s theses can be developed within the framework of this project based on the student’s interests and/or desire to learn new techniques (e.g. CRISPR/Cas9).
If interested, please send a cover letter (at most one page) and a CV to Dr. Joyce Kao. ()
Relevant literature:
[1] Paaby, AB, and Rockman, MV. Cryptic genetic variation: evolution's hidden substrate. Nature Reviews Genetics. 2014, 15: 247-258. doi: 10.1038/nrg3688
[2] Gibson, G. Decanalization and the origin of complex disease. Nature Reviews Genetics. 2009. 10: 134-140. doi: 10.1038/nrg2502