| Differentiation and development of testis in the oviparous lizard, Calotes versicolor (Daud.). | |
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MedLine Citation:
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PMID: 16432882 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The differentiation and development of the testis in the lizard Calotes versicolor was studied histologically and histoenzymatically from the day of oviposition (stage 27) to 2 months after hatching. The study reveals the appearance of the gonadal component as a genital ridge at stage 27. The first sign of testis differentiation is observed at stage 33, which displays a well-developed medulla consisting of seminiferous cords comprising Pre-Sertoli cells. The sex differentiation of the embryonic gonads occurs at stage 34. At this stage, seminiferous cords of the testis are prominent and extensive with many pre-Sertoli cells and few spermatogonia. The interstitial space consists of immature fibroblast-type Leydig cells. Pre-Sertoli cells of the seminiferous cords differentiate into Sertoli cells with a triangular nucleus becoming apparent around stages 36-37. The fibroblast-like Leydig cells differentiate into round matured Leydig cells at stage 40. Quantitative estimation of germ cells reveals that the number of germ cells increases in individual gonads, and in 5-day-old hatchling's, this number multiplies by manifold. Spermatogonia show reductional division in the testis of 1-day-old hatchlings. Histochemical localization of Delta5-3beta-HSDH and G-6-PDH activity appears in the seminiferous cords (medulla) of the testis after sexual differentiation (stage 36), indicating that the embryonic medulla is the site of steroidogenesis and not the cortex in C. versicolor. This study also suggests that morphological differentiation of the gonad precedes detectable steroidogenesis in this species. In 10-day-old hatchling's, Delta5-3beta-HSDH activity is seen in the interstitial cells of the testis, which, however, is not detected in the seminiferous tubules. The intensity of the enzyme activity remains more or less the same in the testis up to 10 days after hatching and begins to increase thereafter. The increase in steroidogenesis parallels the progressive post-hatching increase of the interstitial/Leydig cells. |
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Authors:
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Laxmi S Doddamani |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of experimental zoology. Part A, Comparative experimental biology Volume: 305 ISSN: 1548-8969 ISO Abbreviation: J. Exp. Zoolog. Part A Comp. Exp. Biol. Publication Date: 2006 Mar |
Date Detail:
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Created Date: 2006-01-30 Completed Date: 2006-04-26 Revised Date: 2009-11-03 |
Medline Journal Info:
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Nlm Unique ID: 101168223 Medline TA: J Exp Zool A Comp Exp Biol Country: United States |
Other Details:
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Languages: eng Pagination: 299-308 Citation Subset: IM |
Copyright Information:
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Copyright 2006 Wiley-Liss, Inc. |
Affiliation:
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Department of Zoology, Karnatak University, Dharwad 580 003, India. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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3-Hydroxysteroid Dehydrogenases
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metabolism Animals Female Glucosephosphate Dehydrogenase / metabolism Histocytochemistry Lizards / growth & development*, physiology Male Organogenesis / physiology* Oviposition / physiology Sex Differentiation / physiology Spermatogonia / cytology, physiology Testis / enzymology, growth & development*, physiology |
| Chemical | |
Reg. No./Substance:
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EC 1.1.-/3-Hydroxysteroid Dehydrogenases; EC 1.1.1.49/Glucosephosphate Dehydrogenase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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