Auditory organs in Xenopus laevis and Xenopus tropicalis

Abstract

The genus Xenopus is comprised of over 20 genetically divergent species that occupy aquatic habitats such as lakes, rivers, and swamps south of the African Sahara. Like other anurans, advertisement calls are important signals for reproductive behavior and Xenopus have a vocal apparatus adapted for underwater sound production. The tetraploid Xenopus laevis is a well-established model organism for cell and developmental biology. Xenopus tropicalis, a diploid member of the Silurana group, is a newer Xenopus model for molecular genetics that is suited for transgenic studies. Both species are being used for investigations of inner ear organogenesis. Results presented here use light and confocal microscopy to examine the structure of the auditory organs of X. laevis and X. tropicalis. Images gathered from sectioned tissue stained with hematoxylin/eosin or microdissected organs labeled with Alexa 488 phalloidin (Molecular Probes) and propidium iodide illustrate the organization and innervation of the sensory epithelia of the sacculus, amphibian papilla and basilar papilla of the two species. The data show the similarities between the sensory fields and highlight the size differences of the organs in the two species. [Work supported by grant to EES (NIGMS, NIDCD) and awards to QQ (NASA NMSGC, NIGMS RISE).]