scholarly journals Primordial germ cells in the dorsal mesentery of the chicken embryo demonstrate left-right asymmetry and polarized distribution of the EMA1 epitope

2014 ◽  
Vol 224 (5) ◽  
pp. 556-563 ◽  
Author(s):  
Gideon Hen ◽  
Miriam Friedman-Einat ◽  
Dalit Sela-Donenfeld

Development ◽  
1954 ◽  
Vol 2 (4) ◽  
pp. 275-289
Author(s):  
Enrico Vannini ◽  
Armando Sabbadin

As long ago as 1941 and 1942 one of us (Vannini) found in a series of developmental stages of frog tadpoles that the somatic components of the medullary tissue of the gonad have their origin in the interrenal blastema, and not, as was then generally supposed, in the mesonephric blastema. In the earliest stages examined at that time the gonad rudiment had the structure of ‘paired genital ridges’, lying at each side of the dorsal mesentery, and were furnished with primordial germ-cells, but were still without medullary tissue. The interrenal blastema occupied a median site in the tadpole's body, ventral to the aorta and dorsal to the two subcardinal veins. The mesonephric blastemata appeared distinctly separate from the interrenal rudiment, because they were situated in a more lateral position, contiguous with the Wolffian ducts. In later stages the medullary tissue (‘medulla’) penetrated within the genital ridges.



Development ◽  
1994 ◽  
Vol 120 (1) ◽  
pp. 135-141 ◽  
Author(s):  
M. Gomperts ◽  
M. Garcia-Castro ◽  
C. Wylie ◽  
J. Heasman

Primordial germ cells (PGCs) are the founder cell population of the gametes which form during the sexually mature stage of the life cycle. In the mouse, they arise early in embryogenesis, first becoming visible in the extraembryonic mesoderm, posterior to the primitive streak, at 7.5 days post coitum (d.p.c.). They subsequently become incorporated into the epithelium of the hind gut, from which they emigrate (9.5 d.p.c.) and move first into the dorsal mesentery (10.5 d.p.c.), and then into the genital ridges that lie on the dorsal body wall (11.5 d.p.c.). We have used confocal microscopy to study PGCs stained with an antibody that reacts with a carbohydrate antigen (Stage-Specific Embryonic Antigen-1, SSEA-1) carried on the PGC surface. This allows the study of the whole PGC surface, at different stages of their migration. The appearance of PGCs in tissue sections has given rise to the conventional view that they migrate as individuals, each arriving in turn at the genital ridge. In this paper, we show that PGCs leave the hind gut independently, but then extend long (up to 40 microns) processes, with which they link up to each other to form extensive networks. During the 10.5-11.5 d.p.c. period, these networks of PGCs aggregate into groups of tightly apposed cells in the genital ridges. As this occurs, their processes are lost, and their appearance suggests they are now non-motile. Furthermore, we find that PGCs taken from the dorsal mesentery at 10.5 d.p.c. perform the same sequence of movements in culture.(ABSTRACT TRUNCATED AT 250 WORDS)



Development ◽  
1974 ◽  
Vol 31 (1) ◽  
pp. 75-87
Author(s):  
Piero P. Giorgi

Bufo bufo embryos were used at the tail-bud stage for the grafting of two different dorsal regions (cephalic and caudal tracts) into the ventral side of the embryo (cf. Fig. 1). Germ cell localization was studied at the beginning of larval life. The results seem to confirm the original finding of Gipouloux (1970) who suggested that in anurans germ cells migrate under the attraction of a substance produced by the dorsal mesodermal tissues. The attractive action of dorsal tissue was confined to the caudal region of the embryo. In operated specimens the migration of germ cells was drastically altered. The genital ridges of host embryos were almost sterile, while numerous germ cells appeared associated with caudal grafts. A considerably smaller number of germ cells was associated with cephalic grafts. About 80% of germ cells associated with caudal grafts were present at the same levels where a well-developed dorsal mesentery was also present. It is suggested that the formation of the dorsal mesentery plays a morphogenetic role in segregating primordial germ cells from other endodermal cells and contributes to their final localization in the genital ridges.



2007 ◽  
Vol 86 (10) ◽  
pp. 2182-2193 ◽  
Author(s):  
Y. Nakamura ◽  
Y. Yamamoto ◽  
F. Usui ◽  
T. Mushika ◽  
T. Ono ◽  
...  


1995 ◽  
Vol 8 (6) ◽  
pp. 557-562 ◽  
Author(s):  
Y. H. Hong ◽  
D. S. Seo ◽  
D. K. Jeong ◽  
K. D. Choi ◽  
J. Y. Han


Development ◽  
1961 ◽  
Vol 9 (4) ◽  
pp. 634-641
Author(s):  
A. W. Blackler ◽  
M. Fischberg

There have been many claims for the segregation of Anuran primordial germcells at an early embryonic stage. Most authors agree that these cells may be distinguished with ease in the most dorsal region of the larval endoderm and, somewhat later in development, at the base of the dorsal mesentery and in the undifferentiated gonad (see review by Johnston, 1951). Bounoure (1934) and Blackler (1958) claim to have traced the origin of the primordial germ-cells as early in development as the late blastula stage and to have recognized cell inclusions that become restricted to the germ line at all stages between the fertilized egg and the late blastula. As pointed out by Everett (1945), some workers in this field of embryological study have firmly denied the existence of primordial germ-cells, while others have been cautious of accepting the principle that these cells give rise to any of the definitive sex-cells (gametes).



Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 67-81
Author(s):  
V. Thomas ◽  
J. Heasman ◽  
C. Ford ◽  
D. Nagajski ◽  
C. C. Wylie

Ultra-violet (u.v.) irradiation of the vegetal pole of newly fertilized eggs has three documented effects: reduction of primordial germ cells (PGCs), cytological damage to the vegetal hemisphere and disruption of the normal mechanism by which the vegetal yolk mass induces the formation of the dorsal axis of the embryo. In this study, we find that 90° rotation of the egg for various periods after irradiation rescues the dorsal axial structures but does not restore the number of PGCs found in the dorsal mesentery of the gut; neither is there any correlation between reduced numbers of PGCs and disruption of cleavage at the vegetal pole. We therefore conclude that the effect on the germ line is separate from the other two phenomena. Secondly, 90° rotation of non-irradiated eggs was found to significantly reduce germ cell numbers migrating in the dorsal mesentery of the gut.



Development ◽  
2000 ◽  
Vol 127 (3) ◽  
pp. 447-456 ◽  
Author(s):  
D.W. Houston ◽  
M.L. King

Xdazl is an RNA component of Xenopus germ plasm and encodes an RNA-binding protein that can act as a functional homologue of Drosophila boule. boule is required for entry into meiotic cell division during fly spermatogenesis. Both Xdazl and boule are related to the human DAZ and DAZL, and murine Dazl genes, which are also involved in gamete differentiation. As suggested from its germ plasm localization, we show here that Xdazl is critically involved in PGC development in Xenopus. Xdazl protein is expressed in the cytoplasm, specifically in the germ plasm, from blastula to early tailbud stages. Specific depletion of maternal Xdazl RNA results in tadpoles lacking, or severely deficient in, primordial germ cells (PGCs). In the absence of Xdazl, PGCs do not successfully migrate from the ventral to the dorsal endoderm and do not reach the dorsal mesentery. Germ plasm aggregation and intracellular movements are normal indicating that the defect occurs after PGC formation. We propose that Xdazl is required for early PGC differentiation and is indirectly necessary for the migration of PGCs through the endoderm. As an RNA-binding protein, Xdazl may regulate translation or expression of factors that mediate migration of PGCs.



Author(s):  
Amreek Singh ◽  
Warren G. Foster ◽  
Anna Dykeman ◽  
David C. Villeneuve

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.



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


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