Chimaeric analysis reveals role of Pdgf receptors in all muscle lineages.
Nat Genet
; 18(4): 385-8, 1998 Apr.
Article
em En
| MEDLINE
| ID: mdl-9537425
ABSTRACT
Blood vessels originate as simple endothelial cell tubes. It has been proposed that platelet-derived growth factor B polypeptide (Pdgfb) secreted by these endothelial cells drives the formation of the surrounding muscular wall by recruiting nearby mesenchymal cells. However, targetted inactivation of the Pdgfb gene or the Pdgf receptor beta (Pdgfrb) gene, by homologous recombination, does not prevent the development of apparently normal large arteries and connective tissue. We have used an in vivo competition assay in which we prepared chimaeric blastocysts, composed of a mixture of wild-type (Pdgfrb[+/+]) and Pdgfrb(+/-) or wild-type and Pdgfrb(-/-) cells, and quantified the relative success of cells of the two component genotypes in competing for representation in different cell lineages as the chimaeric embryos developed. This study revealed that the participation of Pdgfrb(-/-) cells in all muscle lineages (smooth, cardiac, skeletal and pericyte) was reduced by eightfold compared with Pdgfrb(+/+) cells, and that participation of Pdgfrb(+/-) cells was reduced by twofold (eightfold for pericytes). Pdgfrb inactivation did not affect cell contribution to non-muscle mesodermal lineages, including fibroblasts and endothelial cells. Chimaera competition is therefore a sensitive, quantitative method for determining developmental roles of specific genes, even when those roles are not apparent from analysis of purebred mutants; most likely because they are masked by homeostatic mechanisms.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Quimera
/
Receptores do Fator de Crescimento Derivado de Plaquetas
/
Músculos
Limite:
Animals
Idioma:
En
Revista:
Nat Genet
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
1998
Tipo de documento:
Article
País de afiliação:
Estados Unidos