25. Preliminary Ultrastructural Analysis of Spermiogenesis in Western Mexico Whiptail Lizard, Aspidoscelis costatus

Jaime Rhodes University of Indianapolis, Mikia Davis University of Indianapolis, Katie Rust University of Indianapolis
Faculty Sponsor(s): Kevin Gribbins University of Indianapolis
To date, there are multiple studies detailing the ultrastructure of spermatozoa within the genus Aspidoscelis and within the family Teiidae. However, there are no complete data on the process of spermiogensis within a species of Whiptail Lizard or within Ground Lizards. The purpose of this investigation is to provide the first detailed study on the entire ultrastructural process of spermiogenesis within Aspidocelis costatus. These results can then be compared to the spermatozoa data that is available for Teiidae. Testicular tissues of A. costatus were fixed, dehydrated, embedded in epon, sectioned with an ultramicrotome, and viewed under TEM. A. costatus spermatids were found to be relatively conserved to that of other squamates. This preliminary data on A. costatus spermatids will provide new species and familial characteristics that can be compared to that of the previously studied saurian taxa. The features of the spermatids that will be concentrated on in this study are: changes to the acrosome, midpiece mitochondrial morphology, the morphology of the nucleus and flagellum, and the progression of the manchete during the process of spermatid development. Recently, spermatid ultrastructural data has been suggested as a tool that could be utilized in phylogenetic analysis; however, to date too few species have successfully been studied. Thus, the new data set provided by the present study will add to the needed ultrastructural information known for lizards and provide another species of squamate that could increase our understanding of the evolutionary relationships of Ground Lizards to that of other squamates.
Poster Presentation

When & Where

Irwin Library 3rd Floor