Changes in the morphology of the germinal dense bodies in primordial germ cells of the teleost, Oryzias latipes

1985 ◽  
Vol 240 (3) ◽  
pp. 669-673 ◽  
Author(s):  
Satoshi Hamaguchi
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Oryzias Latipes ◽  
Dense Bodies

Sex differentiation of germ cells in the teleost, Oryzias latipes, during normal embryonic development

Development ◽  
1972 ◽  
Vol 28 (2) ◽  
pp. 385-395
Author(s):  
Noriyuki Satoh ◽  
Nobuo Egami
Keyword(s):  
Germ Cells ◽  
Meiotic Prophase ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Oryzias Latipes ◽  
The Other ◽  
Histological Structure ◽  
The Mean ◽  
Further Development ◽  
Normal Embryonic Development

Mitotic and meiotic activities of germ cells during early development in the medaka, Oryzias latipes, are dealt with in this report. Primordial germ cells were obviously distinguishable from somatic cells 3 days after fertilization and began to proliferate about 7 days after fertilization. The mean number of primordial germ cells increased during a period of 7–10 days after fertilization, reaching about 90 immediately before hatching. Newly hatched fry could be classified into two types according to the number and the nucleic activity of germ cells in the gonadal rudiment. One type consisted of fry containing about 100 germ cells and no cells in the meiotic prophase. In the other type of fry the number of germ cells increased by mitotic divisions and some of the cells began to enter into the meiotic prophase. During the course of further development the fry of the former type differentiated into males and the latter into females. Therefore it can be concluded that the morphological sex differentiation of germ cells occurs at the time of hatching. However, no sexual differences in the histological structure of somatic elements in the gonad are observable at that time.

The vasa-like gene, olvas, identifies the migration path of primordial germ cells during embryonic body formation stage in the medaka, Oryzias latipes

2000 ◽  
Vol 42 (4) ◽  
pp. 317-326 ◽  
Author(s):  
Ai Shinomiya ◽  
Minoru Tanaka ◽  
Tohru Kobayashi ◽  
Yoshitaka Nagahama ◽  
Satoshi Hamaguchi
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Oryzias Latipes ◽  
Migration Path ◽  
Body Formation ◽  
Formation Stage

Differentiation of primordial germ cells in the embryonic development of Thermobia domestica, Pack. (Thysanura): an ultrastructural study

Development ◽  
1977 ◽  
Vol 38 (1) ◽  
pp. 93-114
Author(s):  
Jerzy Klag
Keyword(s):  
Embryonic Development ◽  
Germ Cells ◽  
Morphological Changes ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Postembryonic Development ◽  
Thermobia Domestica ◽  
Dense Bodies ◽  
Accessory Nuclei ◽  
High Degree

The primordial germ cells (PGCs) of Thermobia domestica undergo some morphological changes during the embryonic development. Most conspicuous are the changes in the ultrastructure of the nucleus, whose envelope shows a high degree of activity. Two types of vesicles bleb off from the nucleus; the ones with the light interior are called the accessory nuclei, the others, with electron-opaque contents, have been termed the dense bodies. The nucleolus, initially clustered at the nucleus centre, undergoes dispersion and assembles again towards the end of embryonic development. At the same time, the sex differentiation of PGCs takes place. It is preceded by an increase in the activity of Golgi complexes and in the volume of lysosomes and lamellar bodies, the latter giving rise to lipid droplets. At the early stages of postembryonic development, preoogonia and prespermatogonia can readily be distinguished. Preoogonia have a wavy-surfaced nucleus and their cytoplasm contains dense bodies. In prespermatogonia, the nucleus is spherical with smooth envelope and there are no dense bodies in the cytoplasm. Throughout the period studied there occur nucleolus-like bodies and nuage material considered to be the germ-cell determinants in this species.

scholarly journals Mutations affecting early distribution of primordial germ cells in Medaka (Oryzias latipes) embryo

2004 ◽  
Vol 121 (7-8) ◽  
pp. 817-828 ◽  
Author(s):  
Takao Sasado ◽  
Chikako Morinaga ◽  
Katsutoshi Niwa ◽  
Ai Shinomiya ◽  
Akihito Yasuoka ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Oryzias Latipes

Effects of γ-Ray Irradiation on Primordial Germ Cells in Embryos of Oryzias latipes

1977 ◽  
Vol 72 (1) ◽  
pp. 164 ◽  
Author(s):  
Ken-ichi Ijiri ◽  
Nobuo Egami
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Oryzias Latipes ◽  
Γ Ray
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