Bone Research; Researchers from Cornell University report details of new studies and findings in the area of bone research

18 February 2009
Biotech Week, (c) Copyright 2009, Biotech Week via NewsRx.com

2009 FEB 18 - (NewsRx.com) - According to recent research from the United States, "Allen's Rule documents a century-old biological observation that strong positive correlations exist among latitude, ambient temperature, and limb length in mammals. Although genetic selection for thermoregulatory adaptation is frequently presumed to be the primary basis of this phenomenon, important but frequently overlooked research has shown that appendage outgrowth is also markedly influenced by environmental temperature."

"Alteration of limb blood flow via vasoconstriction/vasodilation is the current default hypothesis for this growth plasticity, but here we show that tissue perfusion does not fully account for differences in extremity elongation in mice. We show that peripheral tissue temperature closely reflects housing temperature in vivo, and we demonstrate that chondrocyte proliferation and extracellular matrix volume strongly correlate with tissue temperature in metatarsals cultured without vasculature in vitro. Taken together, these data suggest that vasomotor changes likely modulate extremity growth indirectly, via their effects on appendage temperature, rather than vascular nutrient delivery," wrote M.A. Serrat and colleagues, Cornell University.

The researchers concluded: "When combined with classic evolutionary theory, especially genetic assimilation, these results provide a potentially comprehensive explanation of Allen's Rule, and may substantially impact our understanding of phenotypic variation in living and extinct mammals, including humans."

Serrat and colleagues published their study in Proceedings of the National Academy of Sciences of the United States of America (Temperature regulates limb length in homeotherms by directly modulating cartilage growth. Proceedings of the National Academy of Sciences of the United States of America, 2008;105(49):19348-19353).
For additional information, contact M.A. Serrat, Cornell University, Dept. of Biomedical Science, T5-002 VRT, Ithaca, NY 14853, USA.

Publisher contact information for the journal Proceedings of the National Academy of Sciences of the United States of America is: National Acad Sciences, 2101 Constitution Avenue NW, Washington, DC 20418, USA.