What determines body size?

Aug 03, 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.

These three factors are independent of each other and each of them is determined by many genes.

The regulation of body size is therefore the result of the interactions among many genes involved in many different processes. These processes are themselves strongly influenced by external factors such as temperature and nutrition and Nijhout et al.’s study therefore sheds light on how environmental and genetic factors can interact to determine final adult body size.

Their new model is likely to have broad applicability and could explain size variations in flies and other insects as well as in moths.

Source: BioMed Central Limited

Explore further: REM sleep critical for young brain development; medication interferes

Related Stories

Shrinking fish sizes in exploited stocks

Jun 26, 2015

An experimental study with size-selectively harvested zebrafish that began in 2006 at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin, Germany reveals that size-selective harvesting causes changes ...

Study takes close look at formidable camel spider jaws

Jun 22, 2015

For the first time, researchers have created a visual atlas and dictionary of terms for the many strange features on the fearsome-looking jaws of a little known group of arachnids. Called camel spiders, baardskeerders ...

Carrying a table together with a robot

Jun 19, 2015

From a robot's perspective, humans are normally a nuisance: when robots and humans have to work together, it often leads to problems. Researchers on CogIMon, a new project starting at Bielefeld University, ...

Why we still collect butterflies

Jun 11, 2015

Who doesn't love butterflies? While most people won't think twice about destroying a wasp nest on the side of the house, spraying a swarm of ants in the driveway, or zapping pesky flies at an outdoor barbecue, ...

Recommended for you

Noise from fireworks threatens young ears

8 hours ago

(HealthDay)—The Fourth of July weekend is a time for celebrations and beautiful fireworks displays. But, parents do need to take steps to protect their children's ears from loud fireworks, a hearing expert ...

Many new teen drivers 'crash' in simulated driving task

8 hours ago

(HealthDay)—Around four in 10 newly licensed teen drivers "crashed" in a simulated driving test, suggesting that many adolescents lack the skills they need to stay safe on the road, according to a new study.

New test could predict arthritis drug failure in patients

9 hours ago

A study of 311 patients by The University of Manchester has found that it may be possible to predict early which rheumatoid arthritis (RA) patients will fail to respond to the biologic drugs given to treat them. These findings ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.