Meeting Abstract
Terrestrial ectothermic reptiles are under increasing risk of global warming. Embryonic life is particularly sensitive to thermal stress, although few studies have examined the tissue- and stage-specific effects of thermal stress in reptiles. We have examined the production of developmental malformations in the burgeoning embryological model system Anolis sagrei. Examination of field incubation conditions indicates that this species is developing on the cusp of its thermal limits during the peak summer months. We have discovered a narrow window around ovipositon that is sensitive to thermal stress and the concomitant induction of developmental malformations. Craniofacial malformations represent the most abundant class of malformation observed. These malformations range from a foreshortened or narrow face to embryos with complete loss of the neural crest derived facial skeleton. We have shown that these malformations are correlated with localized cell death in the developing forebrain during a narrow window of craniofacial patterning. Using a concentration gradient of a small inhibitors applied directly to the developing egg we have reproduced the craniofacial phenotypes observed in the thermally stressed embryos, verifying our candidate mechanism of induction. Our results raise greater concern over the potential for climate change to disrupt the reproduction and survival of terrestrial ectotherms.
