Temporal and spatial aspects of the gradual migration of primordial germ cells from the epiblast into the germinal crescent in the avian embryo

Development ◽  
1986 ◽  
Vol 95 (1) ◽  
pp. 53-71
Author(s):  
Malka Ginsburg ◽  
Hefzibah Eyal-Giladi
Keyword(s):  
Germ Cells ◽  
Lower Layer ◽  
Primordial Germ Cells ◽  
Avian Embryo ◽  
Chick Blastoderm ◽  
Stage 4 ◽  
Temporal And Spatial ◽  
To Come ◽  
Normal Controls ◽  
Do So

The migration of the PGCs from a stage XIII epiblast into the germinal crescent of a stage 10 chick blastoderm was experimentally investigated. Considerable numbers of PGCs start to come down from the epiblastic layer at stage XII–XIII and continue to do so in relatively smaller numbers until stage 6. The earliest PGCs land on the primary hypoblast and probably are carried by it into the GC. The PGCs that descend at relatively later stages land on the mesodermal wings and are either carried by them passively, or move actively into the GC. After the removal of the lower layer from stage 4 and older blastoderms, there is no regeneration of a GC in the blastoderm. Other consequences of this operation are that the mesodermal wings do not spread anteriorly as in normal controls and the PGCs that are still in the mesodermal domain are trapped. PGCs were found in explants of the lower layer and of the mesoderm. No identifiable PGCs were encountered in explants of the PS.

Spatially restricted activity of a Drosophila lipid phosphatase guides migrating germ cells

Development ◽  
2001 ◽  
Vol 128 (6) ◽  
pp. 983-991 ◽  
Author(s):  
M. Starz-Gaiano ◽  
N.K. Cho ◽  
A. Forbes ◽  
R. Lehmann
Keyword(s):  
Acid Phosphatase ◽  
Germ Cells ◽  
Normal Development ◽  
Primordial Germ Cells ◽  
Phospholipid Hydrolysis ◽  
Lipid Phosphatase ◽  
Phosphatidic Acid Phosphatase ◽  
Migratory Path ◽  
Restricted Activity ◽  
Temporal And Spatial

Temporal and spatial controls of cell migration are crucial during normal development and in disease. Our understanding, though, of the mechanisms that guide cells along a specific migratory path remains largely unclear. We have identified wunen 2 as a repellant for migrating primordial germ cells. We show that wunen 2 maps next to and acts redundantly with the previously characterized gene wunen, and that known wunen mutants affect both transcripts. Both genes encode Drosophila homologs of mammalian phosphatidic acid phosphatase. Our work demonstrates that the catalytic residues of Wunen 2 are necessary for its repellant effect and that it can affect germ cell survival. We propose that spatially restricted phospholipid hydrolysis creates a gradient of signal necessary and specific for the migration and survival of germ cells.

Serotonin receptors are selectively expressed in the avian germ cells and early embryos

Zygote ◽  
2014 ◽  
Vol 23 (3) ◽  
pp. 394-405 ◽  
Author(s):  
Urszula Stępińska ◽  
Takashi Kuwana ◽  
Bożenna Olszańska
Keyword(s):  
Germ Cells ◽  
Serotonin Receptors ◽  
Communication Systems ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Rt Pcr ◽  
Signalling Molecule ◽  
Early Embryos ◽  
Stage 4 ◽  
Polymerase Chain

SummaryThe expression of nine serotonin (5-HT) receptor transcripts was studied using reverse transcription polymerase chain reaction (RT-PCR) in germ cells, cleavage and gastrulation stages of Japanese quail, and qPCR for 5-HT3and 5-HT4receptors in oocytes and embryos. We show the presence/absence of nine serotonin transcripts known in birds for receptors 5-HT1A, 5-HT1F, 5-HT2B, 5-HT2C, 5-HT3, 5-HT4, 5-HT5A, 5-HT6and 5-HT7Ain avian germ cells and early embryos. The absence of 5-HT3and 5-HT5Ain primordial germ cells and of 5-HT3and 5-HT7Ain sperm is characteristic. All transcripts appeared in oocytes at all stages (except for 5-HT3and 5-HT5Atranscripts) and all were present in cleaving embryos and at gastrulation, except for 5-HT3, which was permanently observed as late as in stage 4. Interestingly, 5-HT3and 5-HT5Areceptors accumulated in 3-mm and F1 oocytes but were degraded at ovulation and started to be re-transcribed in cleavage stage II embryos and beyond. The selective appearance of 5-HT receptors in germ cells and early embryos supports the hypothesis that serotonin may act as a signalling molecule at early stages of germ line and embryo differentiation via individual receptors present during different stages, when specialized communication systems are not yet developed.

Primordial germ cells of the young chick blastoderm originate from the central zone of the area pellucida irrespective of the embryo-forming process

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 209-219 ◽  
Author(s):  
M. Ginsburg ◽  
H. Eyal-Giladi
Keyword(s):  
Germ Cells ◽  
Marginal Zone ◽  
Primordial Germ Cells ◽  
Central Zone ◽  
Forming Process ◽  
Chick Blastoderm ◽  
Central Disc ◽  
Axis Of Symmetry ◽  
Experimental Group ◽  
Area Pellucida

Early chick blastoderms (stages X-XII) were divided by a circular cut into two fragments. In one experimental group, the area opaca was separated from the marginal zone and the central disc of the area pellucida, while in another group the area opaca plus marginal zone were separated from the central disc. Other blastoderms of equivalent stages were each cut into three strips of equal size (either perpendicular or parallel to the axis of symmetry). The fragments were isolated and incubated for 43–48 h after which they were PAS-stained, whole-mounted and checked for the presence of primordial germ cells (PGCs). The results showed that most of the PGCs originated from the central disc and not from the periphery of the area pellucida and that they segregated from this zone even if no embryonic axis developed in the explant. In such cases, the PGCs were found to be dispersed throughout the entire explant, usually in association with forming blood islands. When an axis did develop in the explant, the PGCs were found to be concentrated around its anterior end, in a pattern resembling the germinal crescent. No indication of a quantitative regulation of PGCs was found in the explants and the sum of PGCs, calculated for the complementary fragments of a blastoderm, matched the range of numbers in control blastoderms. Our results suggest that PGCs may already be determined as early as stage X and that their further differentiation is independent of the embryo-forming process.

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

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.

Transfusion of Chick Primordial Germ Cells into Quail Embryos and their Settlement in Gonads

1998 ◽  
Vol 69 (10) ◽  
pp. 911-915 ◽  
Author(s):  
Tamao ONO ◽  
Ryohei YOKOI ◽  
Seishi MAEDA ◽  
Takao NISHIDA ◽  
Hirohiko AOYAMA
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells
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