Brenda Nunez University of Indianapolis
Faculty Sponsor(s): Kevin Gribbins University of IndianapolisPresently, little is still known of spermatid development during spermiogenesis in snakes. There are only two complete ultrastructural study on ophidians that detail spermatid ultrastructure within the Cottonmouth and Sea Snake. Therefore, this research was carried out with the goal of expanding our knowledge of the ontogenic steps of spermiogenesis within snakes by studying spermatid maturation in Masticophis flagellum via transmission electron microscopy. M. flagellum were collected in Arkansas in the fall of 2013. The testes were removed and fixed in Trumps and tissues were processed for standard electron microscopy. Many of the ultrastructural details of spermatids in the sea snake are similar to what has been described for squamates and ophidians. There are a few notable differences in the spermatids of M. flagellum compared to the previously studied viperids. There is not a well-developed lacuna within the nucleus, the dense collar is underdeveloped, and the epinuclear lucent zone in the acrosome is longer and more conspicuous in M. flagellum spermatids. Other features of chromatin condensation and morphology of the acrosome complex are similar to what has been observed in the Cottonmouth and Sea Snake. Though the spermatids in P. platurus appear to be highly conserved, there were differences in subcellular details from previously studied snakes. The importance of such character differences during spermiogenesis in snakes is still unknown. Presently the number of species investigated is to small to unravel the phylogenetic implications of such key character differences during spermiogenesis.
When & Where
Irwin Library 3rd Floor