Meeting Abstract

P2.82  Sunday, Jan. 5 15:30  The effect of density on skeletal development in Xenopus laevis DION, J.; GILMORE, E.*; FERREIRA, A.; MAGLIA, A.M.; SHEARMAN, R.M.; Framingham State Univ, MA; Framingham State Univ, MA; Framingham State Univ, MA; National Science Foundation, Arlington, VA; Framingham State Univ, MA lizzgilmore@gmail.com

Understanding how biodiversity evolves requires knowledge of environmental influences on phenotypic development. A species’ developmental flexibility in response to the environment may dictate how much or little its morphology can vary. Until developmental variation is studied in an environmental context, predictions of phenotype from genotype will remain difficult, if not intractable. To investigate the role of environmental variation on skeletal development, we tested the influence of population density on the growth and ossification of Xenopus laevis (African clawed frog) tadpoles. Tadpoles were reared at two densities (1 tadpole/liter (1 t/L) and 3 tadpoles/liter (3 t/L)) under normal laboratory conditions, and developmental series were collected while maintaining densities. Consistent with previous studies, tadpoles in the higher density treatment group experienced an increased rate of mortality and were relatively smaller (snout-vent length by stage) than tadpoles in the lower density treatment group. The ossification sequence between treatment groups varied little, with the exception of delayed onset of ossification of some of the jaw elements, most notably the premaxilla, in the 3 t/L tadpoles. The overall lack of variation in ossification sequence between groups could be due to insufficient difference in the environmental conditions tested or may indicate developmental entrenchment of ossification sequence in Xenopus laevis.