SICB 2015: How Do Anoles Get Big?

photo from; photo by:Uwe Bartlet ?

One of the largest anoles, Anolis equestris (photo by Uwe Bartlett)

From the diminutive twig anole to the monstrous crown-griant anoles, Anolis lizards vary dramatically in their body size. Much research has focused on the patterns of body size variation among Caribbean species, how changes in body size are correlated with habitat differences among species, and rates of body size evolution upon invasion to new islands, yet an important question remains to be addressed in this body of literature, “how do anoles change body size?” S. Griffis and Dr. D. Jennings of Southern Illinois University at Edwardville are attempting to address this among Cuban anoles by searching for DNA sequence differences in known growth factories. But they are using what might be considered an unlikely model for lizard body size variation: dogs. Several years ago, Elaine Ostrander’s lab at the NIH uncovered that coding differences in the growth factors IGF were responsible for the body size variation in dogs. To a mechanist like myself, it was a surprise that this variation could be traced to coding differences in the genes, not to the levels of circulating growth factors. The authors of this poster are following Ostrander’s lead by looking for coding differences in genes involved with the IGF growth axis. But to keep their options open they are also collecting data on circulating hormone levels. When complete, if there are differences in the IGF growth axis contributing to differences in body size, Griffis and Jennings will find it.

About Thomas Sanger

Thom Sanger is an Assistant Professor at Loyola University in Chicago. His lab specializes on understanding the developmental bases of Anolis lizard diversity.

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