Ultrastructure of spermiogenesis in the Cottonmouth, Agkistrodon piscivorus (Squamata: Viperidae: Crotalinae)
Article first published online: 13 OCT 2009
Copyright © 2009 Wiley-Liss, Inc.
Journal of Morphology
Volume 271, Issue 3, pages 293–304, March 2010
How to Cite
Gribbins, K. M., Rheubert, J. L., Anzalone, M. L., Siegel, D. S. and Sever, D. M. (2010), Ultrastructure of spermiogenesis in the Cottonmouth, Agkistrodon piscivorus (Squamata: Viperidae: Crotalinae). J. Morphol., 271: 293–304. doi: 10.1002/jmor.10798
- Issue published online: 3 FEB 2010
- Article first published online: 13 OCT 2009
- Manuscript Accepted: 16 AUG 2009
- Manuscript Revised: 14 JUL 2009
- Manuscript Received: 28 MAY 2009
- National Science Foundation. Grant Number: DEB-0809831
- germ cell development
To date multiple studies exist that examine the morphology of spermatozoa. However, there are limited numbers of data detailing the ontogenic characters of spermiogenesis within squamates. Testicular tissues were collected from Cottonmouths (Agkistrodon piscivorus) and tissues from spermiogenically active months were analyzed ultrastructurally to detail the cellular changes that occur during spermiogenesis. The major events of spermiogenesis (acrosome formation, nuclear elongation/DNA condensation, and flagellar development) resemble that of other squamates; however, specific ultrastructural differences can be observed between Cottonmouths and other squamates studied to date. During acrosome formation vesicles from the Golgi apparatus fuse at the apical surface of the nuclear membrane prior to making nuclear contact. At this stage, the acrosome granule can be observed in a centralized location within the vesicle. As elongation commences the acrosome complex becomes highly compartmentalized and migrates laterally along the nucleus. Parallel and circum-cylindrical microtubules (components of the manchette) are observed with parallel microtubules outnumbering the circum-cylindrical microtubules. Flagella, displaying the conserved 9 + 2 microtubule arrangement, sit in nuclear fossae that have electron lucent shoulders juxtaposed on either side of the spermatids basal plates. This study aims to provide developmental characters for squamates in the subfamily Crotalinae, family Viperidae, which may be useful for histopathological studies on spermatogenesis in semi-aquatic species exposed to pesticides. Furthermore, these data in the near future may provide morphological characters for spermiogenesis that can be added to morphological data matrices that may be used in phylogenetic analyses. J. Morphol. 2010. © 2009 Wiley-Liss, Inc.