The molecular origin of quantitative morphological evolution
Developmental Biology
Evolutionary Cell and Developmental Biology (Zoology)
Final Report Abstract
The diversity of animal forms results from changes in shape, changes in size, as well as the emergence of new characters. The genetic origin of these evolutionary changes begins to be well understood. There is, however, another level of morphological diversification that remains much less understood, the quantitative variation of characters, such as the continuous range of colors or hues that decorate animals. To address this problem, we used the different shades of gray of a pigmentation spot that ornate the wings of fruit flies species closely related to the model organism Drosophila melanogaster. Combining Drosophila genetics, molecular biology and advanced quantitative image analysis, we have compared the DNA regions that control the expression of the pigmentation gene yellow among 11 closely related Drosophila species. We have found that changes in yellow regulatory region have tuned the amount of gene expression during evolution, resulting in proportional amount of pigmentation in each species. Interestingly, the difference between a species with a very dark spot and a species with a light gray spot did not emerge from a single or few mutations. Instead, we found that the difference is explained by progressive changes that have accumulated along the entire regulatory region. One of these changes appears to affect the control of chromatin –how accessible the regulatory region is between species–, a kind of mechanism that was never invoked in the context of regulatory evolution.
Publications
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Regulatory evolution tuning pigmentation intensity quantitatively in Drosophila. Science Advances, 10(4).
Bachem, Katharina; Li, Xinyi; Ceolin, Stefano; Mühling, Bettina; Hörl, David; Harz, Hartmann; Leonhardt, Heinrich; Arnoult, Laurent; Weber, Sabrina; Matarlo, Blair; Prud’homme, Benjamin & Gompel, Nicolas
