Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-4-15
pubmed:abstractText
Cultures of Xenopus blastula animal caps were used to explore the haematopoietic effects of three candidate inducers of mesoderm: basic fibroblast growth factor (bFGF), bone morphogenetic proteins (BMPs) and activin A. In response to either bFGF or activin A, explants expanded into egg-shaped structures, and beneath an outer layer of epidermis, a ventral mesodermal lining surrounded a fluid-filled cavity containing "blood-like cells". Immunocytochemistry identified some of these cells as early leukocytes, but erythrocytes were rare. BMP-2 or BMP-4 induced primitive erythrocytes as well as leukocytes, and a high concentration was required for these cells to differentiate in only a small proportion of explants. BMP-2 but not BMP-4 induced ventral mesoderm concomitantly. High concentrations of activin A dorsalized explants, which contained infrequent leukocytes, and an optimal combination of activin A and bFGF caused differentiation of muscle with few blood cells. By contrast, BMP-2 or BMP-4 plus activin A synergistically increased the numbers of both leukocytes and erythrocytes. Explants treated with BMPs plus activin contained a well organized cell mass in which yolk-rich cells mixed with blood cells and pigmented cells did not. BMP-2 plus bFGF also induced numerous leukocytes and fewer erythrocytes, but BMP-4 antagonized the leukopoietic effect of bFGF. The data suggest that the signalling pathways these three factors use to induce leukopoiesis overlap and that erythropoiesis may be activated when inducers are present in combination.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0949-944X
pubmed:author
pubmed:issnType
Print
pubmed:volume
209
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
69-76
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Blood cell induction in Xenopus animal cap explants: effects of fibroblast growth factor, bone morphogenetic proteins, and activin.
pubmed:affiliation
Department of Life Sciences (Biology), Graduate School of Arts and Science, Tokyo University, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't