Occurrence and ultrastructural characterization of "nuage" during oogenesis and early spermatogenesis of Piaractus mesopotamicus Holmberg, 1887 (Teleostei)

Abstract

We investigated the occurrence and ultrastructurally characterized electrondense nuclear material (nuage) released from the nucleus during oogenesis and early spermatogenesis of Piaractus mesopotamicus, a fish from Pantanal Matogrossense (Brazil) having a seasonal reproductive cycle. The female germ cells presented two instances of nuclear material extrusion: in the oogonia and in the oocyte in the perinucleolar phase. In males, material with similar morphology and behavior occurred in the spematogonia. In all cases, this material was associated to mitochondria. The possible function of this material is discussed.

Structure and ultrastructure of oogenic stage in short mackerel Rastrelliger brachysoma (Teleostei: Scombidae)

“…Although to study the oogenic ultrastructure of R. brachysoma has been similarly described in some fishes (ABDALLA and CRUZ-LANDIM, 2003;ABDEL-AZIZ, AL-OTAIBI, OSMAN et al, 2012), the use of TEM provided us to better the understanding the components in both cellular and organelles during oogenic process of this species. The prominent characterization of oogonium as well as earliest stage had nucleolar materials with several nuages, in which the common feature did not differ from previously described in several authors (ABDALLA and CRUZ-LANDIM, 2004). The appearance of the nuages in this stage, R. brachysoma referring to the electron-dense masses, from the fact that were scatted and observed in association with mitochondria near nuclear membrane throughout the lipid and cortical stage, as similar to that of Piaractus productivity during aquacultural development.…”

“…Several large vacuoles in the ooplasm appeared ( Figures 4B, 4C). No microvilli together with the disintegration mesopotamicus (ABDALLA and CRUZ-LANDIM, 2004). Previous suggestion is supported that nuage may involve the oogenic development for fishes because the synthetic activity of the ribonucleoprotein with ribosomic content is found in this structure (ALBERTS, JOHNSON, LEWIS et al, 2007).…”

Morphological characterization of the gonads of bullfrog tadpoles (Lithobates catesbeianus)

“…Inside the oocytes, a region described in the literature as an aggregate of RNA and mitochondria, the Balbiani body or nuage is in accordance with the description by Costa, Lima, Andrade et al (1998), Abdalla and Cruz-Landim (2004), Prado, Abdalla, Silva et al (2004); Okuthe (2012) for adults of anuran. This RNA is condensed in micronucleoli into the nuclei and transferred to the cytoplasm during the early stages of oogenesis (ABDALLA and CRUZ-LANDIM, 2004).…”