Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021
Erindi/veggspjald / Talk/poster E14
Höfundar / Authors: Baldur Kristjánsson (1), Dagný Á. Rúnarsdóttir (1), Sudarshan Chari (2), Ian Dworkin (3), Arnar Pálsson (1)
Starfsvettvangur / Affiliations: 1. University of Iceland, Reykjavík, Iceland, 2. Princeton University, Princeton, USA, 3. McMaster University, Hamilton, Canada
Kynnir / Presenter: Baldur Kristjánsson
How do regulatory networks evolve in response to genetic perturbations? We generally think of adaptive evolution as the accumulation of beneficial or neutral mutations. However, deleterious mutations are widespread in eukaryotic populations and can hitchhike with adaptive mutations and rise in frequency and even be fixed. When a major mutation is fixed in a population, its effects on aspects of the phenotype can in principle be reversed by evolution in downstream, parallel or upstream regulatory components. Major mutations can expose cryptic genetic variation in populations, and compensatory selection can act on this variation to restore fitness and potentially also phenotypes. We are interested in the molecular mechanisms responsible for compensatory evolution in response to genetic perturbations. Focusing on the sensitivity and buffering of regulatory networks we study tissue specific changes in strains of Drosophila melanogaster, that have undergone genetic introgressions of mutations in the genes vestigial, net and rhomboid, that affect wings and veins. Replicate populations were either subjected to selection for improved wing shape (evolved) or “natural” selection (against the harmful effects of the mutations, i.e. controls). Transcriptional response was strongest in the vestigial mutation and our results suggest that cryptic standing genetic variation, within wild populations, can compensate and even restore expression of a disrupted gene.