What controls animal stripes? Math has the answer

CAMBRIDGE, Mass., Dec. 23 (UPI) -- A newly developed math model, detailed this week in the journal Cell Systems, is helping scientists better understand animal stripes.

Scientists say the existence of stripes is relatively easy to explain. Stripes emerge as cellular interaction creates high and low concentrations of pigment, chemical or cell types.

But researchers at Harvard wanted to know what determines the orientation stripes.

To find out, researchers built a new math model combining several decades of research into animal stripes into a single predictive equation.

"We wanted a very simple model in hopes that it would be big picture enough to include all of these different explanations," lead study author Tom Hiscock, a PhD student studying systems biology at Harvard Medical School, said in a press release. "We now get to ask what is common among molecular, cellular, and mechanical hypotheses for how living things orient the directions of stripes, which can then tell you what kinds of experiments will (or won't) distinguish between them."

Researchers were able to use their new model to identify factors affecting stripe orientation.

Whether stripes are vertical or horizontal can be influenced by a "production gradient," a substance that affects the density of stripe patterns. Orientation could also be affected by an alteration in "parameter gradient," a substance that augments the stripe formation process. Lastly, orientation could be influenced by a molecular, cellular, or mechanical change in the direction of the stripes' origins.

Currently, these factors are all theoretical -- not grounded in corresponding biological factors. But researchers believe the mathematical analysis will finally help scientists find these influential factors within living organisms.