Development and ultrastructural autoradiographic studies of nucleolus-like bodies (nuages) in oocytes of a viviparous teleost (Xiphophorus helleri)

Azevedo, Carlos

doi:10.1007/bf00215152

Cited by 36 publications

(26 citation statements)

References 29 publications

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“…This material, also referred to as "germinal dense bodies," "nucleolus like bodies," and "intermitochondrial cement," has been observed consistently, not only in primordial germ cells but also in oogonia, oocytes, spermatogonia, spermatocytes, and even spermatids of fishes (Satoh, 1974;Bruslé and Bruslé, 1978;Hamaguchi, 1982Hamaguchi, , 1992Azevedo, 1984;Billard, 1984;Gevers et al, 1992;Flores and Burns, 1993;Grandi and Colombo, 1997;Quagio-Grassiotto and Carvalho, 1999;Grier, 2000;Guimaraes and Quagio-Grassiotto, 2001;Lo Nostro et al, 2003;Ravaglia and Maggese, 2003). Nuage appears to be synthesized in the nucleus (Azevedo, 1984) and contains ribonucleoproteins (Toury et al, 1977) that may represent ribosomal components that are subsequently assembled in the cytoplasm (Flores and Burns, 1993). In C. dimerus, nuage is observed close to the nuclear envelope (Figs.…”

Section: Discussionmentioning

confidence: 94%

Gonadal development and sex differentiation in the cichlid fishCichlasoma dimerus (Teleostei, perciformes): A light- and electron-microscopic study

2005

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Although the overall pattern and timing of gonadal sex differentiation have been established in a considerable number of teleosts, the ultrastructure of early stages of gonadal development is not well documented. In this study, gonads from larval and juvenile stages of laboratory-reared Cichlasoma dimerus were examined at the light-microscopic and ultrastructural levels. This freshwater species adapts easily to captivity and spawns with high frequency during 8 months of the year, providing an appropriate model for developmental studies. Larvae and juveniles were kept at a water temperature of 26.5 +/- 1 degrees C and a 12:12 hour photoperiod. Gonadal development was documented from 14-100 days postfertilization, covering the period of histologically discernible sex differentiation. Gonadal tissue was processed according to standard techniques for light and electron microscopy. C. dimerus, a perciform teleost, is classified as a differentiated gonochorist, in which an indifferent gonad develops directly into a testis or ovary. On day 14, the gonadal primordium consists of a few germ cells surrounded by enveloping somatic cells. Ovarian differentiation precedes testicular differentiation, as usual in teleost fishes. The earliest signs of differentiation, detected from day 42 onward, include the onset of meiotic activity in newly formed oocytes, which is soon accompanied by increased oogonial mitotic proliferation and the somatic reorganization of the presumptive ovary. The ovarian cavity is completely formed by day 65. Numerous follicles containing perinucleolar oocytes are observed by day 100. In contrast, signs of morphological differentiation in the presumptive testis are not observed until day 72. By day 100, the unrestricted lobular organization of the testis is evident. The latest stage of spermatogenesis observed by this time of testicular development is spermatocyte II.

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Section: Discussionmentioning

confidence: 94%

Gonadal development and sex differentiation in the cichlid fishCichlasoma dimerus (Teleostei, perciformes): A light- and electron-microscopic study

2005

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“…Others, however, have suggested that it is responsible for the generation of organelles such as mitochondria and ribosomes (e.g., Azevedo, 1984;Toury et al, 1977). Recent studies have shown that the structure (and hence the function?)…”

Section: Other Cellular Events Occurring During Oocyte Growth Nuagementioning

confidence: 96%

Ultrastructural aspects of oogenesis and oocyte growth in fish and amphibians

Wallace

Selman

1990

J. Elec. Microsc. Tech.

233

152

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Oogenesis, the early events of primary oocyte growth (meiotic arrest, synapsis, ribosomal gene duplication), and folliculogenesis can be seen to particular advantage in the germinal ridge of the syngnathan ovary. After budding off the germinal ridge (a compartment of the luminal epithelium), nascent follicles then enter into a linear array of developing follicles within which temporal and stage-specific events can be correlated with spatial distribution. Prominent features of the later phase of primary oocyte growth include intense transcriptional activity and the formation and subsequent dispersal of the Balbiani vitelline body (mitochondrial cloud) concomitant with an increase in cytoplasmic organelles and volume. Further oocyte growth is characterized by a period of cortical alveolus (in teleosts) or cortical granule (in anurans) formation, in which Golgi elements play a predominant role, and finally vitellogenesis. The latter process, which is responsible for the preponderance of oocyte growth, includes the hepatic synthesis and secretion of vitellogenin (VTG), the uptake of VTG from the bloodstream into the oocyte by receptor-mediated endocytosis, and the transport of VTG via endosomes and multivesicular bodies to forming yolk platelets. In the process, VTG is proteolytically cleaved into the yolk proteins, which assume either a monoclinic (in cyclostomes) or orthorhombic (in teleosts and amphibians) crystalline array. Other structures associated with the growing oocyte are also briefly discussed, including nuage, the vitelline envelope, intercellular junctions between the oocyte and overlying follicle cells, pigment, intramitochondrial crystals in ranidae, and annulate lamellae.

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“…3c) . Some fibrillar material was always discernible, called 'ciment' when associated with mitochondria, called 'nuage' when independent (Azevedo 1984) . Spermatogonia, surrounded by Sertoli cells and gathered into nests, were observed in the most peripheric part of the male area .…”

Section: Ovotestes With Testicular Prevalencementioning

confidence: 99%

Plasticity of gonad development in hermaphroditic sparids: ovotestis ontogeny in a protandric species, Lithognathus mormyrus

Besseau

Brusle-Sicard

1995

Environ Biol Fish

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SynopsisHeterosexual gonad development in a sparid species, Lithognathus mormyrus, was studied by histological and cytological examination, during the first three years of life . Gonad bisexuality is achieved after two months of development, according to the cytological dynamics known in sparids . In one-year-old fishes, a variability in the gonad morphology of the juvenile ovotestis is shown : three different types of ovotestis have been identified within the same cohort : ovotestes with testicular prevalence (25%), testicular and ovarian equivalence (20%), and ovarian prevalence (55%) . This morphological variability of the juvenile ovotestes was consistent with the histocytological analysis of the sexual structure of the adult stock at the first sexual maturity, which constituted 55 .5% of functional males (stemming from the first two types of ovotestis) and 44.5 % of primary females (from the third type) . The plasticity of sexual expression in sparids is emphasized, revealing the potentialities of the ovotestis .

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Development and ultrastructural autoradiographic studies of nucleolus-like bodies (nuages) in oocytes of a viviparous teleost (Xiphophorus helleri)

Cited by 36 publications

References 29 publications

Gonadal development and sex differentiation in the cichlid fishCichlasoma dimerus (Teleostei, perciformes): A light- and electron-microscopic study

Gonadal development and sex differentiation in the cichlid fishCichlasoma dimerus (Teleostei, perciformes): A light- and electron-microscopic study

Ultrastructural aspects of oogenesis and oocyte growth in fish and amphibians

Plasticity of gonad development in hermaphroditic sparids: ovotestis ontogeny in a protandric species, Lithognathus mormyrus

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