The level of sexual dimorphism depends on the environment where Silene latifolia grows. We are looking for QTL based on a cross between dry and wet environments, with a special interest to those that localise on the sex chromosomes.
I previously worked on homomorphic sex chromosomes on both the common frog Rana temporaria and the annual dioecious plant Mercurialis annua, in the University of Lausanne, in the labs of Nicolas Perrin, John Pannell and Mark Kirkpatrick.
The sex chromosome unique to the heterogametic sex (Y or W) is affected by evolutionary forces that lead to its degeneration. Recent studies on non-model organisms, however, identify many cases of sex chromosomes that are not differentiated in the heterogametic sex, questioning the inevitability of sex chromosome degeneration.
I have also worked on sexual selection in Drosophila (D. montana - Mike Ritchie, Roger Butlin, Anneli Hoikkala and D. pseudoobscura Mike Ritchie, Rhonda Snook) and a neo-sex chromosome hybrid zone on the grasshopper Podisma pedestris (Richard Nichols).
Lines with large and small flowers (good for females and males, respecively) have been generated. Gene expression differences between those lines should reveal the first genes that respond to such sexually antagonistic selection.
Incomplete penetrance of sex determination in frogs, and achiasmatic meiosis in males, allows for interesting possibilities in the evolution of a new sex chromosome.
A study of viability and fertility of YY plants allows to determine the phenotypic effects of possible Y chromosome degeneration.
Variation in the extent of sex chromosome differentiation exists within the same population for the common frog, Rana temporaria. This alows to directly compare possible effects on male fitness while controlling for the rest of the genome, and the environment.