Maternal Nanos-Dependent RNA Stabilization in the Primordial Germ Cells of Drosophila
 Embryos

In many insect eggs, including those of the Diptera, deeply staining granules, rich in RNA, occur in the posterior polar plasm and during ontogeny become enclosed within the pole cells. The structure and fate of these cells, which generally give rise to the primordial germ cells, and their inclusions have excited interest for over half a century (Hegner, 1908; Huettner, 1923; Rabinowitz, 1941; Poulson, 1947; Counce, 1963; Mahowald, 1962), yet numerous questions concerning them remain unsettled or controversial to this day. For instance, the dual fate of the pole cells in Drosophila, the genus which has been most extensively studied, is still debated (Poulson & Waterhouse, 1960; Hathaway & Selman, 1961). Recently, Counce (1963), in a light-microscope study, has described the developmental morphology of the polar granules in several species of Drosophila embryos; while Mahowald (1962) has succeeded in identifying them in D. melanogaster at the ultra-structural level.

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A truncated form of a transcription factor Mamo activates vasa in Drosophila embryos

Communications Biology ◽

10.1038/s42003-019-0663-4 ◽

2019 ◽

Vol 2 (1) ◽

Author(s):

Shoichi Nakamura ◽

Seiji Hira ◽

Masato Fujiwara ◽

Nasa Miyagata ◽

Takuma Tsuji ◽

...

Keyword(s):

Transcription Factor ◽

Germ Cells ◽

Primordial Germ Cells ◽

Transcriptional Activator ◽

Transcriptional Regulators ◽

Truncated Form ◽

Germline Development ◽

Finger Protein ◽

Biochemical Studies ◽

Drosophila Embryos

AbstractExpression of the vasa gene is associated with germline establishment. Therefore, identification of vasa activator(s) should provide insights into germline development. However, the genes sufficient for vasa activation remain unknown. Previously, we showed that the BTB/POZ-Zn-finger protein Mamo is necessary for vasa expression in Drosophila. Here, we show that the truncated Mamo lacking the BTB/POZ domain (MamoAF) is a potent vasa activator. Overexpression of MamoAF was sufficient to induce vasa expression in both primordial germ cells and brain. Indeed, Mamo mRNA encoding a truncated Mamo isoform, which is similar to MamoAF, was predominantly expressed in primordial germ cells. The results of our genetic and biochemical studies showed that MamoAF, together with CBP, epigenetically activates vasa expression. Furthermore, MamoAF and the germline transcriptional activator OvoB exhibited synergy in activating vasa transcription. We propose that a Mamo-mediated network of epigenetic and transcriptional regulators activates vasa expression.

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Hexachlorobenzene toxicity in the rat ovary: II. Ultrastructure induced by medium (10 mg/kg) dose exposure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012374x ◽

1992 ◽

Vol 50 (1) ◽

pp. 668-669

Author(s):

Amreek Singh ◽

Warren G. Foster ◽

Anna Dykeman ◽

David C. Villeneuve

Keyword(s):

Germ Cells ◽

Primordial Germ Cells ◽

Surface Epithelium ◽

Morphological Parameters ◽

Comprehensive Investigation ◽

Ovary Surface Epithelium ◽

Rat Ovary ◽

High Doses

Hexachlorobenzene (HCB) is a known toxicant that is found in the environment as a by-product during manufacture of certain pesticides. This chlorinated chemical has been isolated from many tissues including ovary. When administered in high doses, HCB causes degeneration of primordial germ cells and ovary surface epithelium in sub-human primates. A purpose of this experiment was to determine a no-effect dose of the chemical on the rat ovary. The study is part of a comprehensive investigation on the effects of the compound on the biochemical, hematological, and morphological parameters in the monkey and rat.

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