Role of the Y chromosome (completed)
Genetic architecture in Drosophila - The role of the Y chromosome in gene expression across the genome
About the project
Understanding genetic architecture, the underlying basis of phenotypic traits, and its relationship to evolutionary change, is a major challenge for evolutionary biologists. Variation in gene expression is one of the most important factors causing this phenotypic variation. We will study the role of the Y chromosome of Drosophila melanogaster in regulation of gene expression on the X chromosomes and the autosomes. Widespread regulatory effects of the Y chromosome was discovered in a study published in Science in 2008 by the Hartl laboratory using Y chromosomes from different populations in the same genetic background and measuring the difference in gene expression with a spotted microarray platform. The discovery of Y-linked regulatory variation (YRV) on a genome-wide scale is a new phenomenon that motivates studies of its mechanisms,
adaptive significance, and evolutionary dynamics. Our hypothesis is that the polymorphic Y chromosome differs in the number of binding sites that compete with YRV-responsive genes for chromatin-associated proteins that are present in limited amounts in the cells. We want to: A) Identify which region(s) of the Y chromosome regulate genes whose expression is modulated by YRV; B) Measure the difference in microsatellite density on Y chromosomes from different Drosophila lines. C) Correlate PEV (position-effect variegation) phenotypes with polymorphism on the Y chromosome. D) Test the involvement of known regulatory pathways in YRV, especially the pathway mediated by suppressors of PEV [Su(var)] and that mediated by repeat-associated small inhibitory RNA (rasiRNA); E) Determine which genes modulated by YRV are differentially affected by polymorphic Y present in XXY females. Arguing in favor of our hypothesis is the known high degree of polymorphism in rDNA and Su(Ste) repeats, the effect of the Y chromosome in modulating PEV, and the specificity of binding of key chromatin-associated proteins with microsat sequences in the Y.
Project funded by The Research Council of Norway.
Start: 01.02.2010. End: 14.04.2014.