Fate of the Donor Blastodermal Cells Derived from the Central Disc, Marginal Zone and Area Opaca Transferred into the Recipient Embryos

Mitsuru Naito; Akiko Sano; Yuko Matsubara; Takashi Harumi; Takahiro Tagami; Michiharu Sakurai; Takashi Kuwana

doi:10.2141/jpsa.38.58

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 ◽

10.1530/rep.0.1210547 ◽

2001 ◽

pp. 547-552 ◽

Cited By ~ 28

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.

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Avian marginal zone cells function as primitive streak inducers only after their migration into the hypoblast

Development ◽

10.1242/dev.120.9.2501 ◽

1994 ◽

Vol 120 (9) ◽

pp. 2501-2509 ◽

Cited By ~ 2

Author(s):

H. Eyal-Giladi ◽

T. Lotan ◽

T. Levin ◽

O. Avner ◽

J. Hochman

Keyword(s):

Incubation Medium ◽

Marginal Zone ◽

Electrophoretic Pattern ◽

Primitive Streak ◽

Electrophoretic Analysis ◽

Avian Embryo ◽

Central Disc ◽

Induction Process ◽

Marginal Zones

Hypoblast cells of posterior marginal zone origin have been shown previously to be the inducers of primitive streak in the avian embryo. Here we checked: (1) whether the above cells acquire their inductivity while still whithin the marginal zone; (2) can inductivity be found in supernatants of defined blastodermic regions; (3) can differences in the electrophoretic pattern be shown between inducing and non-inducing tissue fragments and their conditioned media, which might give a clue as to what the inductive substance is. The following observations were made: 1. (a) Stage X chick posterior marginal zone cells prior to their migration into the hypoblast do not induce a primitive streak, when applied to a stage XIII competent epiblast central disc. (b) A posterior marginal zone fragment, when applied to an epiblast central disc, even after being preincubated for up to 9 hours in vitro, is still non-inductive. (c) Mechanically fragmented stage X posterior marginal zones when applied as a layer to epiblast central discs are non-inductive. (d) Hypoblastic tissue in strip form induces a primitive streak. 2. Competent stage XIII epiblast central discs (chick) were incubated for 2 hours in supernatants of stage XIII epiblasts or hypoblasts. Whereas no inductive effect was exerted by the epiblast supernatant, primitive streaks developed in about 50% of the epiblast central discs incubated in the hypoblast supernatant. 3. Electrophoretic analysis (quails) reveals a protein of 28x10-3 Mr that is enriched in both hypoblastic tissue and its incubation medium and not in the epiblast + marginal zone + area opaca and their incubation medium. These findings suggest a possible correlation between this protein and the induction process.

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

Development ◽

10.1242/dev.101.2.209 ◽

1987 ◽

Vol 101 (2) ◽

pp. 209-219 ◽

Cited By ~ 3

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.

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