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Patterns of paired‐related homeobox genes PRX1 and PRX2 suggest involvement in matrix modulation in the developing chick vascular system
Author(s) -
Bergwerff Maarten,
GittenbergerDe Groot Adriana C.,
Deruiter Marco C.,
Iperen Liesbeth Van,
Meijlink Frits,
Poelmann Robert E.
Publication year - 1998
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/(sici)1097-0177(199809)213:1<59::aid-aja6>3.0.co;2-x
Subject(s) - biology , mesenchyme , adventitia , microbiology and biotechnology , extracellular matrix , vascular smooth muscle , homeobox , anatomy , embryonic stem cell , matrix (chemical analysis) , embryo , gene expression , gene , endocrinology , genetics , smooth muscle , materials science , composite material
Abstract PRX1 ( MHox ) and PRX2 ( S8 ) were previously shown to be expressed throughout embryogenesis in complex, mostly mesenchyme‐specific patterns. In the developing cardiovascular system both genes were highly expressed in prospective connective tissues, that is, endocardial cushions and valves, the epicardium, and the wall of the great arteries and veins. We further scrutinised expression of PRX1 and PRX2 in the developing vascular system of the chicken embryo and compared patterns with those of established vascular differentiation markers (muscle‐actin, procollagen I, and fibrillin‐2). PRX1 and PRX2 expression were associated with the primary vessel wall from early stages onward and became increasingly restricted to the adventitial and outer medial cell layers. PRX1 eventually colocalised strikingly with procollagen I and fibrillin‐2 expression and generally excluded high smooth muscle actin expression. Furthermore, PRX1 expression preceded the segregation of very distinct nonmuscular cells and smooth muscle cells in the media of the great arteries. PRX2 patterns deviated at later stages from those of PRX1 and showed specific and high transcript levels in the ductus arteriosus from embryonic day 6 onward. Results suggest that PRX genes are not essential in smooth muscle contractile differentiation, but may be involved in matrix modulation in the vascular system and possibly in defining the noncontractile cellular phenotype and in media‐adventitia definition. Dev. Dyn. 1998;213:59–70. © 1998 Wiley‐Liss, Inc.