Friday, August 04, 2006
How does a growing organism determine what its final body size will be? In the moth Manduca sexta, also known as the tobacco hornworm and recognisable by its distinctive blue-green caterpillar, adult body size is largely determined at the end of larval life, when the caterpillar has reached it final weight and is about to metamorphose into a moth.
In a study published today in the open access journal Journal of Biology, Frederik Nijhout, from Duke University in Durham, USA and colleagues built a new mathematical model that allows them to predict the size of an adult moth, on the basis of three parameters: the initial weight of the juvenile caterpillar, its growth rate and the rate at which the effect of a developmental hormone decays.
Paper referred to above: A quantitative analysis of the mechanism that controls body size in Manduca sexta.
There's also a minireview (The proximate determinants of insect size) in the same Journal of Biology issue which requires free registration (or use your BioMed identity if you have one).