Food, dopamine and skeletons in the ecology, evolution and development of urchin larval form
by Diane K. Adams, PhD Rutgers the State University of New Jersey Institute of Earth, Ocean and Atmospheric Sciences Department of Marine and Coastal Sciences
Form is not solely set by an individual’s genes. The environment, genes and development all interact to create the final product. In many sea urchins, the amount of food in the environment determines the size of the larval feeding apparatus. We show that the sensation of food induces dopamine signaling to inhibit the elongation of the larval feeding arms by modulating growth factor signaling. Thus instead of improving food acquisition, the mechanism underlying this phenotypic plasticity acts to reduce food acquisition potential during periods of abundant resources to preserve maternal energetic reserves. The ability to match energetic expenditure on the feeding apparatus to food availability evolved relatively recently within the clade of the regular sea urchins. Comparative studies suggest that the evolution of plasticity was constrained by the evolution of both the timing of the biomineralization of the supporting skeleton and of neural development. Sea urchin larvae may have co-opted the widespread use of food-induced dopamine signaling from behavioural responses to instead alter their development.
Date & Time
February 25, 2016
12:30 pm-1:30 pm