Electron microscope studies on the hemostatic process in bird embryos

Edmonds, Richard H.

doi:10.1016/s0022-5320(68)90066-x

Cited by 15 publications

(4 citation statements)

References 40 publications

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“…During the course of the present study we could not find so far the cells containing the large size aggregation of glycogen granules which could consistently be seen in the circulating ETs in later embryos (1,7). We think that the glycogenpositive cells shown here are the embryo thromboblasts which just start differentiating and that the scattering granules later make aggregations in several loci of the cytoplasm during maturation and migration of those immature thromboblasts.…”

Section: Electron Microscopic Observationscontrasting

confidence: 51%

The Blood Island is a Site of Formation of the Primary Embryo Thrombocyte in the Chick Blastoderm

Tahara¹,

Morinaka²

1990

Dev Growth Differ

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~~ ~Using the immunohistological technique we inquired at what developmental stage and in which site of chick blastoderm does the embryo thrombocyte (ET) begin to differentiate. An anti-ET antibody was raised against rabbits by injecting ETs isolated from blood of 10 day chick embryos. By applying the indirect staining method to smear preparations of blood collected from developing embryos it was confirmed that cytoplasm of the ET showed more intense staining than that of the erythroid cell and that the ET population could be distinguished from the erythrocyte population by this antibody. Cells showing the intense staining could be detected first in blood islands of the area opaca vasculosa of stage 9+ blastoderms. These embryo thromboblasts were found singly or in groups of a small number at dorsal periphery of cell clusters in the blood island. The electron microscopy revealed that embryo thromboblasts appeared in the same position in the stage 9+ blastoderm. At stage 10+ or later embryo thromboblasts were also present adhering to the vascular endothelium or free in the vessel lumen. We conclude that ETs start differentiating from primitive mesenchymal cells localized in the blood island of the area opaca vasculosa at stage 9 or earlier, migrate thereafter to vessel lumen, and enter the blood stream.

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Section: Electron Microscopic Observationscontrasting

confidence: 51%

The Blood Island is a Site of Formation of the Primary Embryo Thrombocyte in the Chick Blastoderm

Tahara¹,

Morinaka²

1990

Dev Growth Differ

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“…EDMONDS (4) first reported that glycogen deposits are consistently present in thrombocytes of chick embryos. As we have often confirmed this during electron microscopic studies on virhs production in embryonic thrombocytes, we thought that the presence of glycogen granules could be employed as a specific marker to distinguish thrombocytes from erythroid cells.…”

mentioning

confidence: 99%

Formation of Embryo Thromboblasts in Chick Blastoderm: Morphology, Site of Production and Time of Emergence in the Blood

Tahara¹,

Omori²,

Hashimoto³

1983

Dev Growth Differ

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Thrombocytes in the blood of chick embryos (termed embryo thrombocytes by LUCAS and JAMROZ) have PAS-positive granules in their cytoplasm. Electron microscopic observations reveal that the embryo thrombocytes contain glycogen granules present singly or in clumps. The presence of these inclusions and other morphological characteristics were used as specific markers to distinguish embryo thrombocytes from primitive erythroid cells. These markers also made it possible to determine the time at which the immature thromboblasts first emerge in blood vessels, and the period of their continued presence in the circulation. In this way we found that thromboblasts were detectable in embryos as early as stage 10+ of HAMBURGER and HAMILTON (after 35 hr incubation) and that the thromboblasts were present in the circulation until day 4 of incubation (stage 23). In o w and in vitro culture of de-enibryonated blastoderrn demonstrated that thromboblasts were formed in the area opeca vasculosa. The present observations suggest that embryo thromboblasts are formed at the same time and in the same area as the primitive cells of erythroid line.Although it is well established that the thrombocytes found in the circulating blood of chick embryos (named embryo thrombocytes by LUCAS and JAMROZ) become morphologically distinguishable from erythrocytes on day 3 of incubation, i.e., after about 65 hr incubation (1-3), it is still uncertain when they first appear in blood vessels and where they are formed. This is partly because embryo thromboblasts are so similar in morphological appearance to primitive erythoblasts that they could not be distinguished before day 3 of incubation.EDMONDS (4) first reported that glycogen deposits are consistently present in thrombocytes of chick embryos. As we have often confirmed this during electron microscopic studies on virhs production in embryonic thrombocytes, we thought that the presence of glycogen granules could be employed as a specific marker to distinguish thrombocytes from erythroid cells. Therefore, we applied the PAS technique to blood smears from embryos of various ages and found that even in their immature stages thrombocytic cells could be unmistakably identified by this technique. Electron microscopic observations supported this conclusion.The present paper reports the following findings: I ) the embryo thromboblasts can be detected in blood vessels of the yolk sac from as early as stage 10+ of HAMBURGER and HAMILTON (after 35 hr incubation) until about the end of day 4 of incubation, and 2) the thromboblasts are produced in the area opeca vasculosa.

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“…As previously demonstrated by Edmonds (1970), 1065-6995/93/110993--o7/$08.00{0 Chang and Hamilton (1978), and Taffarel and Oliveira (1992), thrombocytes are active phagocytes.…”

Section: Introductionmentioning

confidence: 75%

“…Besides their coagulant function, they participate in the cleansing of the blood as has been previously demonstrated. They are the most efficient phagocytic cells in chicken blood, and compliment other cells in the self defense process (Edmonds 1970, Chang and Hamilton 1979, Taffarel and Oliveira, 1992.…”

Section: Discussionmentioning

confidence: 99%

Cytochemical analysis of the content of chicken thrombocytes vacuoles.

Taffarel¹

1993

Cell Biology International

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The content of the large vacuoles present in chicken thrombocytes was analyzed by the use of cytochemical techniques which indicated the presence of basic proteins, unsaturated fatty acids, sugars rich in viccinal hydroxyl groups, linked to proteins or lipids and acid phosphatase. These substances perform one of the most conspicuous functions of these cells, which is phagocytosis. In addition, thrombocytes are committed to hemostasis. Both functions make these cells similar to human platelets, even though having different origins and morphologic characteristics. The large vacuoles described are connected to the open canalicular system (OCS) and together with other cellular structures they contribute to the endocytic system.

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Electron microscope studies on the hemostatic process in bird embryos

Cited by 15 publications

References 40 publications

The Blood Island is a Site of Formation of the Primary Embryo Thrombocyte in the Chick Blastoderm

The Blood Island is a Site of Formation of the Primary Embryo Thrombocyte in the Chick Blastoderm

Formation of Embryo Thromboblasts in Chick Blastoderm: Morphology, Site of Production and Time of Emergence in the Blood

Cytochemical analysis of the content of chicken thrombocytes vacuoles.

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