Morphological changes in the clasper gland of the Atlantic stingray,Dasyatis sabina, associated with the seasonal reproductive cycle

Reproduction in vertebrates is controlled by the hypothalamo-pituitary-gonadal axis, and both the sex steroid and pituitary hormones play a pivotal role in the regulation of the physiology of the oviduct and events occurring within the oviduct. Their hormonal actions are mediated through interaction with specific receptors. Our aim was to locate α and β estrogen receptors, progesterone receptors, gonadotropin and prolactin receptors in the tissues of the oviduct of Typhlonectes compressicauda (Amphibia, Gymnophiona), in order to study the correlation between the morphological changes of the genital tract and the ovarian cycle. Immunohistochemical methods were used. We observed that sex steroids and pituitary hormones were involved in the morpho-functional regulation of oviduct, and that their cellular detection was dependent on the period of the reproductive cycle.

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Pendrin immunoreactivity in the gill epithelium of a euryhaline elasmobranch

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00178.2002 ◽

2002 ◽

Vol 283 (4) ◽

pp. R983-R992 ◽

Cited By ~ 51

Author(s):

Peter M. Piermarini ◽

Jill W. Verlander ◽

Ines E. Royaux ◽

David H. Evans

Keyword(s):

Collecting Duct ◽

Apical Region ◽

Intercalated Cells ◽

Cortical Collecting Duct ◽

Gill Epithelium ◽

Dasyatis Sabina ◽

Proton Atpase ◽

Atlantic Stingray ◽

Freshwater Stingray ◽

Gill Lamellae

Pendrin is an anion exchanger in the cortical collecting duct of the mammalian nephron that appears to mediate apical Cl−/HCO[Formula: see text]exchange in bicarbonate-secreting intercalated cells. The goals of this study were to determine 1) if pendrin immunoreactivity was present in the gills of a euryhaline elasmobranch (Atlantic stingray, Dasyatis sabina), and 2) if branchial pendrin immunoreactivity was influenced by environmental salinity. Immunoblots detected pendrin immunoreactivity in Atlantic stingray gills; pendrin immunoreactivity was greatest in freshwater stingrays compared with freshwater stingrays acclimated to seawater (seawater acclimated) and marine stingrays. Using immunohistochemistry, pendrin-positive cells were detected on both gill lamellae and interlamellar regions of freshwater stingrays but were more restricted to interlamellar regions in seawater-acclimated and marine stingray gills. Pendrin immunolabeling in freshwater stingray gills was more apical, discrete, and intense compared with seawater-acclimated and marine stingrays. Regardless of salinity, pendrin immunoreactivity occurred on the apical region of cells rich with basolateral vacuolar-proton-ATPase, and not in Na+-K+-ATPase-rich cells. We suggest that a pendrin-like transporter may contribute to apical Cl−/HCO[Formula: see text] exchange in gills of Atlantic stingrays from both freshwater and marine environments.

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The reproductive cycle of the endangered cyprinidAlburnus albidus: Morphological changes of the gonads and plasma sex steroid fluctuations

Italian Journal of Zoology ◽

10.1080/11250009809386818 ◽

1998 ◽

Vol 65 (sup1) ◽

pp. 223-226 ◽

Cited By ~ 5

Author(s):

Giulia Guerriero ◽

Marina Paolucci ◽

Pier Giorgio Bianco ◽

Virgilio Botte ◽

Gaetano Ciarcia

Keyword(s):

Reproductive Cycle ◽

Morphological Changes ◽

Sex Steroid

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Secretion of Rectal Gland Fluid in the Atlantic Stingray, Dasyatis sabina

Copeia ◽

10.2307/1443288 ◽

1977 ◽

Vol 1977 (3) ◽

pp. 585 ◽

Cited By ~ 2

Author(s):

Barry E. Beitz

Keyword(s):

Rectal Gland ◽

Dasyatis Sabina ◽

Atlantic Stingray

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Locomotion evoked by stimulation of the brain stem in the Atlantic stingray, Dasyatis sabina

Journal of Neuroscience ◽

10.1523/jneurosci.10-01-00194.1990 ◽

1990 ◽

Vol 10 (1) ◽

pp. 194-204 ◽

Cited By ~ 14

Author(s):

CA Livingston ◽

RB Leonard

Keyword(s):

Brain Stem ◽

Dasyatis Sabina ◽

Atlantic Stingray ◽

The Brain ◽

Stimulation Of

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Reproductive cycle of the Neotropical cichlid yellow peacock bass Cichla kelberi: A novel pattern of testicular development

Neotropical Ichthyology ◽

10.1590/s1679-62252013000300012 ◽

2013 ◽

Vol 11 (3) ◽

pp. 587-596 ◽

Cited By ~ 8

Author(s):

Diógenes Henrique de Siqueira-Silva ◽

Carlos Alberto Vicentini ◽

Alexandre Ninhaus-Silveira ◽

Rosicleire Veríssimo-Silveira

Keyword(s):

Reproductive Cycle ◽

Germ Cells ◽

Light Microscope ◽

Morphological Changes ◽

Germinal Epithelium ◽

Testicular Development ◽

Preparatory Phase ◽

Testicular Morphology ◽

Peacock Bass ◽

Spermatogonial Proliferation

The present study describes the testicular maturation phases (associating the germ cells development and the morphological changes suffered by the germinal epithelium along the whole year), and the testicular morphology in the yellow peacock bass Cichla kelberi, relating it to other species. For this purpose, 78 specimens were studied according conventional techniques of light microscope. The testes in C. kelberi were classified as unrestricted spermatogonial lobular, an apomorphic characteristic in the recent groups of Teleost. Furthermore, were defined five testicular maturation phases: Preparatory phase; Early Germinal Epithelium Development; Mid Germinal Epithelium Development; Late Germinal Epithelium Development and; Regression. Similar classifications were described to other species indicating that the testicular classifications based on this propose, can be applied to lots of fishes. However, besides it similarity, the testicular reproductive cycle of C. kelberifollows a different pattern in the Regression phase, on which the gonadal restructuration and the spermatogonial proliferation gathers at the same time. So, the testes in C. kelberi never return to the Preparatory phase to start a new reproductive cycle, being this one present only at the first reproductive cycle in this species. This fact also explains the absence of individuals totally spent after their first reproductive cycle.

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