Primordial Germ Cells of Synaptula hydriformis (Holothuroidea; Echinodermata) Are Epithelial Flagellated-Collar Cells: Their Apical-Basal Polarity Becomes Primary Egg Polarity

J. E. Frick; E. E. Ruppert

doi:10.2307/1542920

Primordial Germ Cells of Synaptula hydriformis (Holothuroidea; Echinodermata) Are Epithelial Flagellated-Collar Cells: Their Apical-Basal Polarity Becomes Primary Egg Polarity

Biological Bulletin ◽

10.2307/1542920 ◽

1996 ◽

Vol 191 (2) ◽

pp. 168-177 ◽

Cited By ~ 11

Author(s):

J. E. Frick ◽

E. E. Ruppert

Keyword(s):

Germ Cells ◽

Primordial Germ Cells ◽

Egg Polarity

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Primordial germ cells and oocytes of Branchiostoma virginiae (Cephalochordata, Acrania) are flagellated epithelial cells: relationship between epithelial and primary egg polarity

Zygote ◽

10.1017/s0967199400003816 ◽

1997 ◽

Vol 5 (2) ◽

pp. 139-151 ◽

Cited By ~ 10

Author(s):

Jennifer E. Frick ◽

Edward E. Ruppert

Keyword(s):

Epithelial Cells ◽

Basal Lamina ◽

Germ Cells ◽

Primordial Germ Cells ◽

Somatic Cells ◽

Germinal Epithelium ◽

Connective Tissue Layer ◽

Adult Ovary ◽

Striated Rootlet ◽

Egg Polarity

SummaryPrimordial germ cells (PGCs) are described from the gonad of c. 2 cm juvenile Branchiostoma virginiae; early oocytes (c. 10 μm) and enlarging, previtellogenic oocytes (c. 35 μm) are described from the ovary of c. 5 cm adults. The germinal epithelium of the juvenile gonad and adult ovary is composed of both germinal and somatic cells. In the juvenile, somatic cells retain contact with the basal lamina of the germinal epithelium though their perikarya may be displaced towards the lumen; the germinal epithelium is, therefore, a simple but pseudostratified epithelium. In the adult ovary, somatic cells may lose contact with the basal lamina and the epithelium appears to become stratified. PGCs and oocytes are identified as germ cells by the presence of nuage. PGCs and oocytes are polarised epithelial cells. They rest on a basal lamina, extend apically towards a lumen, form adhering junctions with neighbouring cells, and exhibit apical-basal polarity. PGCs and early oocytes have an apical flagellum with an associated basal body, accessory centriole, and one or more striated rootlet fibres. The flagellum is surrounded by a collar of microvilli. Once oocytes begin to enlarge and bulge basally into the connective tissue layer, the flagellum is lost, but the basal bodies and ciliary rootlets are present at the apex of 35 μm oocytes. Similarities of the oogenic pattern in cephalochordates and echinoderms indicate that the establishment of egg polarity in deuterostomes is influenced by the polarity of the germinal epithelium.

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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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