Posthatching development of Alligator mississippiensis ovary and testis
- 9 December 2009
- journal article
- research article
- Published by Wiley in Journal of Morphology
- Vol. 271 (5), 580-595
- https://doi.org/10.1002/jmor.10818
Abstract
We investigated ovary and testis development of Alligator mississippiensis during the first 5 months posthatch. To better describe follicle assembly and seminiferous cord development, we used histochemical techniques to detect carbohydrate‐rich extracellular matrix components in 1‐week, 1‐month, 3‐month, and 5‐month‐old gonads. We found profound morphological changes in both ovary and testis. During this time, oogenesis progressed up to diplotene arrest and meiotic germ cells increasingly interacted with follicular cells. Concomitant with follicles becoming invested with full complements of granulosa cells, a periodic acid Schiff's (PAS)‐positive basement membrane formed. As follicles enlarged and thecal layers were observed, basement membranes and thecal compartments gained periodic acid‐methionine silver (PAMS)‐reactive fibers. The ovarian medulla increased first PAS‐ and then PAMS reactivity as it fragmented into wide lacunae lined with low cuboidal to squamous epithelia. During this same period, testicular germ cells found along the tubule margins were observed progressing from spermatogonia to round spermatids located within the center of tubules. Accompanying this meiotic development, interstitial Leydig cell clusters become more visible and testicular capsules thickened. During the observed testis development, the thickening tunica albuginea and widening interstitial tissues showed increasing PAS‐ and PAMS reactivity. We observed putative intersex structures in both ovary and testis. On the coelomic aspect of testes were cell clusters with germ cell morphology and at the posterior end of ovaries, we observed “medullary rests” resembling immature testis cords. We hypothesize laboratory conditions accelerated gonad maturation due to optimum conditions, including nutrients and temperature. Laboratory alligators grew more rapidly and with increased body conditions compared with previous measured, field‐caught animals. Additionally, we predict the morphological maturation observed in these gonads is concomitant with increased endocrine activities. J. Morphol. 2010.Keywords
This publication has 68 references indexed in Scilit:
- Growth and Condition of American Alligators (Alligator mississippiensis) in an Inland Wetland of East TexasSoutheastern Naturalist, 2008
- Type IV collagens regulate BMP signalling in DrosophilaNature, 2008
- The testicular capsule and peritubular tissue of birds: morphometry, histology, ultrastructure and immunohistochemistryJournal of Anatomy, 2007
- Extracellular Matrix of the Developing Ovarian FollicleSeminars in Reproductive Medicine, 2006
- Distribution of extracellular matrix proteins type I collagen, type IV collagen, fibronectin, and laminin in mouse folliculogenesisHistochemistry and Cell Biology, 2006
- Basal membrane remodeling during follicle histogenesis in the rat ovary: contribution of proteinases of the MMP and PA familiesDevelopmental Biology, 2005
- Dynamic cross‐talk between cells and the extracellular matrix in the testisBioEssays, 2004
- Seasonal variation in plasma sex steroid concentrations in juvenile American alligatorsGeneral and Comparative Endocrinology, 2004
- Role of distinct type IV collagen networks in glomerular development and functionKidney International, 1998
- A Stereological Study of the Different Cell Populations in Chicken Testes Treated with Follicle‐Stimulating Hormone during Embryonic DevelopmentAnatomia, Histologia, Embryologia, 1997