scholarly journals Insights into blood cell formation from hemogenic endothelium in lesser-known anatomic sites

2016 ◽  
Vol 245 (10) ◽  
pp. 1011-1028 ◽  
Author(s):  
Amanda D. Yzaguirre ◽  
Nancy A. Speck
Keyword(s):  
Blood Cell ◽  
Cell Formation ◽  
Hemogenic Endothelium ◽  
Blood Cell Formation

scholarly journals Multi-Agent Systems and Blood Cell Formation

10.5772/15950 ◽  
2011 ◽  
Author(s):  
Bessonov Nikolai ◽  
Demin Ivan ◽  
Kurbatova Polina ◽  
Pujo-Menjouet Laurent ◽  
Volpert Vitaly
Keyword(s):  
Blood Cell ◽  
Cell Formation ◽  
Multi Agent Systems ◽  
Agent Systems ◽  
Multi Agent ◽  
Blood Cell Formation

Expression of connexin 43 (Cx43) is critical for normal hematopoiesis

Blood ◽  
2000 ◽  
Vol 96 (3) ◽  
pp. 917-924 ◽  
Author(s):  
Encarnacion Montecino-Rodriguez ◽  
Hyosuk Leathers ◽  
Kenneth Dorshkind
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Blood Cell ◽  
Gap Junctions ◽  
Connexin 43 ◽  
Cell Formation ◽  
Cx43 Expression ◽  
Hematopoietic System ◽  
Blood Cell Formation

Abstract Gap junctions are intercellular channels, formed by individual structural units known as connexins (Cx), that allow the intercellular exchange of various messenger molecules. The finding that numbers of Cx43-type gap junctions in bone marrow are elevated during establishment and regeneration of the hematopoietic system has led to the hypothesis that expression of Cx43 is critical during the initiation of blood cell formation. To test this hypothesis, lymphoid and myeloid development were examined in mice with a targeted disruption of the gene encoding Cx43. Because Cx43−/− mice die perinatally, initial analyses were performed on Cx43−/−, Cx43+/−, and Cx43+/+ embryos and newborns. The data indicate that lack of Cx43 expression during embryogenesis compromises the terminal stages of primary T and B lymphopoiesis. Cx43−/− embryos and neonates had a reduced frequency of CD4+ and T-cell receptor-expressing thymocytes and surface IgM+cells compared to their Cx43+/+ littermates. Surprisingly, Cx43+/− embryos/neonates also showed defects in B- and T-cell development similar to those observed in Cx43−/− littermates, but their hematopoietic system was normal at 4 weeks of age. However, the regeneration of lymphoid and myeloid cells was severely impaired in the Cx43+/− mice after cytoablative treatment. Taken together, these data indicate that loss of a single Cx43 allele can affect blood cell formation. Finally, the results of reciprocal bone marrow transplants between Cx43+/+ and Cx43+/− mice and examination of hematopoietic progenitors and stromal cells in vitro indicates that the primary effects of Cx43 are mediated through its expression in the hematopoietic microenvironment.

Blood Cell Formation in Certain Teleost Fishes

Blood ◽  
1951 ◽  
Vol 6 (1) ◽  
pp. 39-60 ◽  
Author(s):  
W. T. CATTON
Keyword(s):  
Blood Cell ◽  
Blood Cells ◽  
Cell Formation ◽  
Large Cell ◽  
Progressive Increase ◽  
Mitotic Division ◽  
Teleost Fishes ◽  
Epithelial Surface ◽  
Alternative Hypotheses ◽  
Blood Cell Formation

Abstract 1. The blood cells of trout and roach consist of nucleated erythrocytes and reticulocytes, nucleated thrombocytes, coarse and fine granulocytes, and lymphocytes of varying sizes. It is difficult to distinguish any cells showing characteristics similar to those of the monocytes of mammals. Immature cells occur more frequently in the blood than is the case in mammals. 2. The coarse granulocytes very commonly escape from the blood vessels, and have been observed in large numbers in the intestinal mucosa and submucosa, in the gill epithelia, and in the peritoneum. These cells migrate to the epithelial surface, where they undergo changes in structure leading to the formation of a characteristic discharge pattern of their granules. It is proposed that the "granules" are in reality vesicles with fluid contents, which are ultimately discharged at epithelial surfaces. 3. The hematopoietic organs of these fishes are chiefly the intertubular tissues of the kidneys; in the trout the spleen is also active; in the roach, only the kidney is active; in the perch, only the spleen is active. 4. Two alternative hypotheses of blood cell formation are proposed. On the first hypothesis, the common stem cell is described as a "large lymphoid hemoblast," which gives rise to granulocytes by direct transformation and undergoes mitotic division to give rise to "small lymphoid hemoblasts." From the latter develop the erythrocytes, thrombocytes and blood lymphocytes. On the second hypothesis, the large lymphoid hemoblast, derived by transformation of reticular cells is the precursor solely of the granulocytes, and the small lymphoid hemoblast is to be derived from endothelial cells and is the precursor of erythrocytes and thrombocytes. In this case the large cell is to be compared with the "primitive white cell" of Doan, Cunningham and Sabin, and the small cell with the "megaloblast" of the same authors. No evidence however is available of the derivation of small hemoblasts from endothelial cell components of the reticulo-endothelium. 5. In the maturation of the erythrocyte in teleost fishes, there is a progressive increase in the size of the cell; in mammals and birds there is a decrease in size. In both cases there is a decrease in size in granulocyte maturation. 6. There are no essential differences between the blood cells and hematopoietic processes of the freshwater and marine teleost fishes examined.

Embryonic Red Blood Cell Formation

Nature ◽  
1972 ◽  
Vol 235 (5337) ◽  
pp. 338-339 ◽  
Author(s):  
VERNON M. INGRAM
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Formation ◽  
Blood Cell Formation
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