The testicular sperm ducts and genital kidney of male Ambystoma maculatum (Amphibia, Urodela, Ambystomatidae)
Article first published online: 29 NOV 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Morphology
Volume 274, Issue 3, pages 344–360, March 2013
How to Cite
Siegel, D. S., Aldridge, R. D., Rheubert, J. L., Gribbins, K. M., Sever, D. M. and Trauth, S. E. (2013), The testicular sperm ducts and genital kidney of male Ambystoma maculatum (Amphibia, Urodela, Ambystomatidae). J. Morphol., 274: 344–360. doi: 10.1002/jmor.20100
- Issue published online: 19 JAN 2013
- Article first published online: 29 NOV 2012
- Manuscript Accepted: 6 OCT 2012
- Manuscript Revised: 10 SEP 2012
- Manuscript Received: 26 JUL 2012
The ducts associated with sperm transport from the testicular lobules to the Wolffian ducts in Ambystoma maculatum were examined with transmission electron microscopy. Based on the ultrastructure and historical precedence, new terminology for this network of ducts is proposed that better represents primary hypotheses of homology. Furthermore, the terminology proposed better characterizes the distinct regions of the sperm transport ducts in salamanders based on anatomy and should, therefore, lead to more accurate comparisons in the future. While developing the above ontology, we also tested the hypothesis that nephrons from the genital kidney are modified from those of the pelvic kidney due to the fact that the former nephrons function in sperm transport. Our ultrastructural analysis of the genital kidney supports this hypothesis, as the basal plasma membrane of distinct functional regions of the nephron (proximal convoluted tubule, distal convoluted tubule, and collecting tubule) appear less folded (indicating decreased surface area and reduced reabsorption efficiency) and the proximal convoluted tubule possesses ciliated epithelial cells along its entire length. Furthermore, visible luminal filtrate is absent from the nephrons of the genital kidney throughout their entire length. Thus, it appears that the nephrons of the genital kidney have reduced reabsorptive capacity and ciliated cells of the proximal convoluted tubule may increase the movement of immature sperm through the sperm transport ducts or aid in the mixing of seminal fluids within the ducts. © J. Morphol., 2013. © 2012 Wiley Periodicals, Inc.