Morphofunctional changes in Leydig cells throughout the continuous spermatogenesis of the freshwater teleost fish, Serrasalmus spilopleura (Characiformes, Characidae): an ultrastructural and enzyme study

Nóbrega, Rafael Henrique; Quagio-Grassiotto, Iranı́

doi:10.1007/s00441-006-0377-z

Cited by 24 publications

(18 citation statements)

References 24 publications

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“…The testicular parenchyma of G. carapo displayed the germinal and interstitial compartments described in all vertebrates. As in other teleost fish (Nobrega and Quagio‐Grassiotto, ; Vazquez et al, ), the seminiferous tubules of this species contained spermatogenic cysts formed by Sertoli cells that envelop a group of synchronously developing germ cells. Histologically, the testis of G. carapo seem to correspond to the unrestricted spermatogonial testicular type, found in most teleosts, where spermatogonia reside along the testicular tubules (Grier et al, ; Grier, ).…”

Section: Discussionsupporting

confidence: 61%

Morphological evidence for a permeability barrier in the testis and spermatic duct ofGymnotus carapo(Teleostei: Gymnotidae)

Souza

Retamal²,

Rocha

et al. 2015

Mol. Reprod. Dev.

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Cell-cell interactions play essential roles in the regulation of gametogenesis. The involvement of junctional complexes in permeability barriers, for example, provides structural and physiological support for male germ-cell development. This study describes morphological characteristics of the reproductive system of Gymnotus carapo, a neo-tropical freshwater fish widely distributed in South and Central America, focusing on the detection of permeability barriers using morphological and biochemical approaches. Ultrastructural analysis of testes treated with the lanthanum nitrate exclusion technique showed that the tracer penetrated the interstitial compartment of the testis, surrounding and appearing within cysts containing spermatogonia and spermatocytes in early stages of meiosis, but was not detected in the spermatid cysts or inside the lumen of spermatogenic tubules. These results suggest the presence of a permeability barrier that is stabilized after meiosis is completed and serves to protect the haploid cells from the vascular system. In the spermatic-duct region, the tracer was obstructed near the lumen of the duct. Junctional complexes and focal tight junctions between adjacent cells were observed in the testis and spermatic duct. Freeze-fracture methods indeed confirmed the presence of tight junctions, which were visualized as parallel rows of individual particles between adjacent cells. More evidence supporting the existence of a permeability barrier was gathered from differences observed in the electrophoretic protein profiles of testis and spermatic-duct fluids compared to blood plasma. Together, these observations demonstrate the existence of a permeability barrier formed by tight junctions in the testis and spermatic duct of G. carapo.

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Section: Discussionsupporting

confidence: 61%

Morphological evidence for a permeability barrier in the testis and spermatic duct ofGymnotus carapo(Teleostei: Gymnotidae)

Souza

Retamal²,

Rocha

et al. 2015

Mol. Reprod. Dev.

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“…The number of steroid-producing LC is positively correlated with spermatogenesis in teleost fish (Kanamori et al 1985, Loir et al 1989, Nobrega & Quagio-Grassiotto 2007. We demonstrated that stable d-males had testes with large groups of LC.…”

Section: Histological and Gene Expression Studies Give Evidence For Dmentioning

confidence: 50%

The social status of the male Nile tilapia (Oreochromis niloticus) influences testis structure and gene expression

Pfennig¹,

Kurth²,

Meißner³

et al. 2012

Reproduction

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Dominant and territorial behaviour are known social phenomena in cichlids and social stress influences reproduction and growth. The gonadotropic hormones trigger spermatogenesis and subordinate males have typically lower levels of gonadotropins than dominant males. In this study, we compared testis morphology and gene expression of dominant and subordinate Nile tilapia males (d-and s-males) in socially stable communities. The d-males had the highest gonadosomatic index but they were not the largest animals in the majority of studied cases. Long-term d-males showed large groups of Leydig cells and hyperplasia of the tunica albuginea due to numerous cytochrome-P450-11b-hydroxylase (Cyp11b) expressing myoid cells. Increased Cyp11b expression in d-males was reflected by elevated 11-ketotestosterone plasma values. However, immunofluorescence microscopy and expression analysis of selected genes revealed that most s-males conserved their capability for spermatogenesis and are, therefore, ready for reproduction when the social environment changes. Moreover, in s-males gene expression analysis by quantitative RT-PCR showed increased transcript levels for germ line-specific genes (vasa, sox2 and dmc1) and Sertoli-specific genes (amh, amhrII and dmrt1) whereas gene expression of key factors for steroid production (sf1 and cyp11b) were reduced. The Nile tilapia is a promising model to study social cues and gonadotropic signals on testis development in vertebrates.

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“…1995; Miura and Miura 2003), the seminiferous tubules and lobules are composed of cysts of spermatogenic cells that are delimited by cytoplasmic projections of the Sertoli cells. As in other teleosts, the Leydig cells of all species studied herein are located in the interstitial compartment of the testis, isolated or in groups, near blood vessels (Nóbrega and Quagio‐Grassiotto 2007).…”

Section: Discussionmentioning

confidence: 67%

Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south‐eastern Brazil

et al. 2010

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Martins, Y.S., de Moura, D.F., Santos, G.B., Rizzo, E. and Bazzoli, N. 2010. Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south-eastern Brazil. -Acta Zoologica (Stockholm). 91: 466-473.This study provides a comparative analysis of gametogenesis of neotropical teleosts Metynnis maculatus, Megalancistrus parananus, Cichla kelberi and Satanoperca pappaterra, through histological, histochemical and histometric techniques. In the ooplasm of C. kelberi and S. pappaterra conspicuous lipid vesicles were observed, which are characteristic of pelagic eggs produced by marine fishes. Perinucleolar oocytes were identified in the testis of S. pappaterra suggesting that this species is protogynous without functional hermaphroditism, an unusual pattern for neotropical fresh-water fishes. The spermatozoa of the studied species have rounded heads, a characteristic of fish that externally fertilise their eggs. The follicular (granulosa) cells of the vitellogenic oocytes from the studied species were cuboidal or columnar, however, in C. kelberi there were columnar follicular cells at the vegetal pole and cuboidal cells at the animal pole. Variations of the histochemical content were detected in the cortical alveoli and follicular cells of vitellogenic oocytes showing differences in the mechanisms to block polyspermy and egg adhesiveness. Larger oocytes were recorded in species which demonstrated parental care behaviour and smaller oocytes were noted in those species with fractioned spawning.Nilo Bazzoli, Programa de Pós-Graduação em Zoologia de Vertebrados, PUC Minas-Av. Dom José Gaspar 500-30535-610,

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Morphofunctional changes in Leydig cells throughout the continuous spermatogenesis of the freshwater teleost fish, Serrasalmus spilopleura (Characiformes, Characidae): an ultrastructural and enzyme study

Cited by 24 publications

References 24 publications

Morphological evidence for a permeability barrier in the testis and spermatic duct ofGymnotus carapo(Teleostei: Gymnotidae)

Morphological evidence for a permeability barrier in the testis and spermatic duct ofGymnotus carapo(Teleostei: Gymnotidae)

The social status of the male Nile tilapia (Oreochromis niloticus) influences testis structure and gene expression

Comparative folliculogenesis and spermatogenesis of four teleost fish from a Reservoir in south‐eastern Brazil

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