Advanced search
Start date
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Immunoexpression of aromatase and estrogen receptors beta in stem spermatogonia of bullfrogs indicates a role of estrogen in the seasonal spermatogonial mitotic activity

Full text
Caneguim, Breno Henrique [1] ; da Luz, Juliana Silva [2] ; Valentini, Sandro Roberto [2] ; Cerri, Paulo Sergio [3] ; Sasso-Cerri, Estela [3]
Total Authors: 5
[1] Fed Univ Sao Paulo Unifesp, Dept Morphol & Genet, Sao Paulo - Brazil
[2] Univ Estadual Paulista, UNESP, Sch Pharmaceut Sci, Dept Biol Sci, Araraquara - Brazil
[3] Univ Estadual Paulista, UNESP, Sch Dent, Dept Morphol, Lab Histol & Embryol, Araraquara - Brazil
Total Affiliations: 3
Document type: Journal article
Source: General and Comparative Endocrinology; v. 182, p. 65-72, FEB 1 2013.
Web of Science Citations: 13

Bullfrog stem spermatogonia, also named primordial germ cells (PGCs), show strong testosterone immunolabeling in winter, but no or weak testosterone immunoexpression in summer. Thus, the role of testosterone in these cells needs to be clarified. In this study, we proposed to evaluate whether PGCs express aromatase and estrogen receptors, and verify a possible role of estrogen in PGCs seasonal proliferation. Testes of male adult bullfrogs, collected in winter (WG) and summer (SG), were fixed and embedded in historesin, for quantitative analysis, or paraffin for immunohistochemistry (IHC). The number of haematoxylin/eosin stained PGCs/lobular area was obtained. Proliferating cell nuclear antigen (PCNA), aromatase, estrogen receptor beta (ER beta) and PCNA/ER beta double immunolabeling were detected by IHC. The number of PCNA-positive PGCs and the histological score (HSCORE) of aromatase and ER beta immunolabeled PGCs were obtained. Although the number of PGCs increased significantly in WG, a high number of PCNA-positive PGCs was observed in summer. Moreover, aromatase and ER beta HSCORE was higher in SG than WG. The results indicate that PGCs express a seasonal proliferative activity; the low mitotic activity in winter is related to the maximal limit of germ cells which can be supported in the large lobules. In SG, the increased ER beta and aromatase HSCORE suggests that testosterone is converted into estrogen from winter to summer. Moreover, the parallelism between the high PGCs mitotic activity and ER beta immunoexpression suggest a participation of estrogen in the control of the PGCs seasonal proliferative activity which guarantee the formation of new germ cysts from summer to next autumn. (c) 2012 Elsevier Inc. All rights reserved. (AU)

FAPESP's process: 09/17895-5 - Morphofunctional evaluation of stem spermatogonia during seasonal spermatogenesis of bullfrog
Grantee:Estela Sasso Cerri
Support Opportunities: Regular Research Grants