Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster V14

Waddingtons landscapes explored: Expression changes associated with genetic assimilation of crossveinless phenotypes

Höfundar / Authors: Baldur Kristjánsson (1), Dagný Ásta Rúnarsdóttir (1), Sarah Marzec (2), Ian Dworkin (2), Arnar Pálsson(2)

Starfsvettvangur / Affiliations: 1. Department of Biology, University of Iceland, Reykjavík, Iceland, 2. Department of Biology, McMaster University, Hamilton, Ontario, Canada

Kynnir / Presenter: Dagný Ásta Rúnarsdóttir

Variation in environmental factors during organisms development can lead to changes in phenotypes. In 1953 Waddington demonstrated that heat-shocked fly pupae developed into flies with partly or fully lost crossveins of the adult wing. Furthermore artificial selection lead to high frequency of this trait in populations. We build on this study and ask what are the molecular basis of the phenomena? And does the selection lead to altered expression of genes in other tissues, than the wing? A wild-type population of Drosophila melanogaster were subjected to heat-shock during development, divided into two groups: with our without crossveins. Replicate populations were subject then to artificial selection on these phenotypes, repeated for 20 generations. Transcriptome libraries were prepared from wing-discs and brains of 3rd instar larvae, sequenced on Illumina HiSeq2500 platform, mapped and counted with Kallisto and analyzed with DEseq2.
Around 100 genes were differently expressed in wing discs, between the crossveinless groups and the control groups. A lot fewer genes showed expression differences in larval brains in the same comparison. Thus environmental perturbation and articifial selection exposed cryptic genetic variation in wild populations, that affects expression of many genes. We also ask how similarly replicate lineages evolved, and via which molecular mechanisms? In conclusion, cryptic genetic variation exposed by environmental insults leads to altered patterns of gene expression.