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.

scholarly journals Localization of primordial germ cells or their precursors in stage X blastoderm of chickens and their ability to differentiate into functional gametes in opposite-sex recipient gonads

Reproduction ◽  
2001 ◽  
pp. 547-552 ◽  
Author(s):  
M Naito ◽  
A Sano ◽  
Y Matsubara ◽  
T Harumi ◽  
T Tagami ◽  
...  
Keyword(s):  
Germ Cells ◽  
Marginal Zone ◽  
Primordial Germ Cells ◽  
Donor Cell ◽  
Same Sex ◽  
White Leghorn Chicken ◽  
Central Disc ◽  
Opposite Sex ◽  
A Cell ◽  
Blastodermal Cells

This study was performed to determine the distribution of primordial germ cells and their precursors in stage X blastoderm of chickens. The blastoderm (Barred Plymouth Rock chickens) isolated from the yolk was separated into three portions: the central disc, the marginal zone and the area opaca. The dissociated blastodermal cells derived from the central disc, marginal zone and area opaca were transferred into a recipient blastoderm (White Leghorn chicken) from which a cell cluster was removed from the centre of the central disc. The manipulated embryos were cultured in host eggshells until hatching. The chicks were raised until sexual maturity and test mated with Barred Plymouth Rock chickens to assess the donor cell contribution to the recipient germline. Germline chimaeric chickens were produced efficiently (46.7%, 7/15) when the blastodermal cells derived from the central disc were transferred into recipient embryos of the same sex, whereas no germline chimaeric chickens were produced when the blastodermal cells derived from the marginal zone or area opaca were transferred into recipient embryos of the same sex (0/12). Germline chimaeric chickens were also produced by transfer of blastodermal cells derived from the central disc (6.7%, 1/15), marginal zone (10.0%, 1/10) or area opaca (11.1%, 1/9) into recipient embryos of the opposite sex. It is concluded that primordial germ cells are induced during or shortly after stage X and that the cells derived from the central disc have the highest potential to give rise to germ cells. Cells derived from the marginal zone and area opaca can also give rise to germ cells, although the frequency is low.

Primordial germ cells in normal and transected duck blastoderms

Development ◽  
1968 ◽  
Vol 20 (3) ◽  
pp. 247-260
Author(s):  
Teresa Rogulska
Keyword(s):  
Chick Embryo ◽  
Blood Vessels ◽  
Germ Cells ◽  
Anterior Part ◽  
Primordial Germ Cells ◽  
Primitive Streak ◽  
Experimental Investigations ◽  
Suggestive Evidence ◽  
Area Pellucida

Suggestive evidence for the extragonadal origin of germ cells in birds was first presented by Swift (1914), who described primordial germ cells in the chick embryo at as early a stage as the primitive streak. According to Swift, primordial germ cells are originally located extra-embryonically in the anterior part of the blastoderm and occupy a crescent-shaped region (‘germinal crescent’) on the boundary between area opaca and area pellucida. Swift also found that primordial germ cells later enter into the blood vessels, circulate together with the blood throughout the whole blastoderm and finally penetrate into the genital ridges, where they become definitive germ cells. Swift's views have been confirmed in numerous descriptive and experimental investigations. Among the latter, the publications of Willier (1937), Simon (1960) and Dubois (1964a, b, 1965a, b, 1966) merit special attention. Dubois finally proved that the genital ridges exert a strong chemotactic influence on the primordial germ cells.

150 THE DISTRIBUTION PATTERN OF PRIMORDIAL GERM CELLS IN EARLY CHICK EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 192 ◽  
Author(s):  
Y. Nakamura ◽  
Y. Yamamoto ◽  
F. Usui ◽  
T. Ono ◽  
K. Takeda ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Central Zone ◽  
Staging System ◽  
Vascular Network ◽  
Chick Embryos ◽  
Chicken Embryos ◽  
The Future ◽  
The Mean

In all vertebrates, primordial germ cells (PGCs) appear during early stages of development in extragonadal sites, then they migrate to the gonad and give rise to ova or spermatozoa. Unlike in other species, however, in avian and reptile embryos, PGCs use the vascular system as a vehicle to transport them to the future gonadal region where they leave the blood vessels. The present study was carried out to know the details of this unique migration pathway and the proliferation of endogenous PGCs in chicken embryos. Whole of the chicken embryos during stages X [Roman numerals refer to the staging system of Eyal-Giladi and Kochav (1976 Dev. Biol. 49, 321–327) to 17 (Arabic numerals refer to the staging system of Hamburger and Hamilton (1951 J. Morphol. 88, 49-82))] or embryonic blood during stages 12 to 17 were immunohistochemical stained using specific antibody raised against chicken vasa homolog (CVH), which could be recognized as a marker for chicken PGCs. The distribution patterns and populations of PGCs in embryos were observed under a stereomicroscope. The numbers of PGCs were presented mean and standard deviation (mean � SD). Anti-CVH staining revealed the distribution and population of chicken PGCs in early chick embryos. PGCs existed mainly in the area pellucida and concentrated in the central zone at stage X. The mean number of PGCs per embryo at this stage was 130.4 � 31.9. With the formation of primitive streak, PGCs were carried anteriorly to the edge of the blastoderm. The PGCs scattered anteriorly began to concentrate to the anterior point of the head on the dorsal side of stage 10 embryos. The average number of PGCs per embryo at stage 10 was 439.3 � 93.6. The mean numbers of PGCs per embryo during stages X to 10 increased gradually as development progressed to stage 10. We found the entrance point of PGCs from anterior edge of the blastoderm to the vascular network during stages 10 to 11. In the blood, PGCs could be detected from all of the samples during stages 12 to 17. In contrast, no PGC was recognized in the future gonadal region before stage 14, and then they began to appear in the same region at stage 15. The mean numbers of PGCs that located in the future gonadal region during stages 15 to 17 increased intensively and were 97.3 � 57.3, 200.3 � 113.5, and 327.6 � 102.4, respectively. Interestingly, the numbers of PGCs within future gonadal region during stages 15 to 17 were consistently and significantly different (P < 0.05) between the left and right side of the region. The results suggest that chicken PGCs move from extraembryonic area to the vascular network during stages 10 to 11, circulate in the blood stream, and finally, they begin to leave the blood vessels actively and migrate to the future gonadal region at stage 15.

Isolation of chicken vasa homolog gene and tracing the origin of primordial germ cells

Development ◽  
2000 ◽  
Vol 127 (12) ◽  
pp. 2741-2750 ◽  
Author(s):  
N. Tsunekawa ◽  
M. Naito ◽  
Y. Sakai ◽  
T. Nishida ◽  
T. Noce
Keyword(s):  
Germ Cells ◽  
Germ Plasm ◽  
Primordial Germ Cells ◽  
Central Zone ◽  
Molecular Probe ◽  
Specific Expression ◽  
Basal Portion ◽  
Mitochondrial Cloud ◽  
Vasa Gene ◽  
Immunohistochemical Analyses

To obtain a reliable molecular probe to trace the origin of germ cell lineages in birds, we isolated a chicken homolog (Cvh) to vasa gene (vas), which plays an essential role in germline formation in Drosophila. We demonstrate the germline-specific expression of CVH protein throughout all stages of development. Immunohistochemical analyses using specific antibody raised against CVH protein indicated that CVH protein was localized in cytoplasm of germ cells ranging from presumptive primordial germ cells (PGCs) in uterine-stage embryos to spermatids and oocytes in adult gonads. During the early cleavages, CVH protein was restrictively localized in the basal portion of the cleavage furrow. About 30 CVH-expressing cells were scattered in the central zone of the area pellucida at stage X, later 45–60 cells were found in the hypoblast layer and subsequently 200–250 positive cells were found anteriorly in the germinal crescent due to morphogenetic movement. Furthermore, in the oocytes, CVH protein was predominantly localized in granulofibrillar structures surrounding the mitochondrial cloud and spectrin protein-enriched structure, indicating that the CVH-containing cytoplasmic structure is the precursory germ plasm in the chicken. These results strongly suggest that the chicken germline is determined by maternally inherited factors in the germ plasm.

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.

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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