TY - JOUR
T1 - Efficient cre-mediated deletion in cardiac progenitor cells conferred by a 3′UTR-ires-Cre allele of the homeobox gene Nkx2-5
AU - Stanley, Edouard G.
AU - Biben, Christine
AU - Elefanty, Andrew
AU - Barnett, Louise
AU - Koentgen, Frank
AU - Robb, Lorraine
AU - Harvey, Richard P
PY - 2002/12/1
Y1 - 2002/12/1
N2 - Conditional gene targeting and transgenic strategies utilizing Cre recombinase have been successfully applied to the analysis of development in mouse embryos. To create a conditional system applicable to heart progenitor cells, a Cre recombinase gene linked at its 5′ end to an internal ribosome entry site (IRES) was inserted into the 3′ untranslated region of the cardiac homeobox gene Nkx2-5 using gene targeting. Nkx2-5IRESCre mice were fully viable as homozygotes. We evaluated the efficacy of Cre-mediated deletion by crossing Nkx2-5IRESCre mice with the Cre-dependent R26R and Z/AP reporter strains. Efficient deletion was observed in the cardiac crescent and heart tube in both strains. However, the Z/AP locus showed transient resistance to deletion in caudal heart progenitors. Such resistance was not evident at the R26R locus, suggesting that Cre-mediated deletion in myocardium may be locus-dependent. From cardiac crescent stages, deletion was seen not only in myocardium, but also endocardium, dorsal mesocardium and pericardial mesoderm. The Cre domain apparently includes cells dorsal to the heart that have been shown to constitute a secondary heart field, contributing myocardium to the outflow tract. Other sites of Nkx2-5 expression, including pharyngeal endoderm and its derivatives, branchial arch epithelium, stomach, spleen, pancreas and liver, also showed efficient deletion. Our data suggest that the Nkx2-5IRESCre strain will be useful for genetic dissection of the multiple tiers of lineage allocation to the forming heart as well as of molecular interactions within the heart fields and heart tube.
AB - Conditional gene targeting and transgenic strategies utilizing Cre recombinase have been successfully applied to the analysis of development in mouse embryos. To create a conditional system applicable to heart progenitor cells, a Cre recombinase gene linked at its 5′ end to an internal ribosome entry site (IRES) was inserted into the 3′ untranslated region of the cardiac homeobox gene Nkx2-5 using gene targeting. Nkx2-5IRESCre mice were fully viable as homozygotes. We evaluated the efficacy of Cre-mediated deletion by crossing Nkx2-5IRESCre mice with the Cre-dependent R26R and Z/AP reporter strains. Efficient deletion was observed in the cardiac crescent and heart tube in both strains. However, the Z/AP locus showed transient resistance to deletion in caudal heart progenitors. Such resistance was not evident at the R26R locus, suggesting that Cre-mediated deletion in myocardium may be locus-dependent. From cardiac crescent stages, deletion was seen not only in myocardium, but also endocardium, dorsal mesocardium and pericardial mesoderm. The Cre domain apparently includes cells dorsal to the heart that have been shown to constitute a secondary heart field, contributing myocardium to the outflow tract. Other sites of Nkx2-5 expression, including pharyngeal endoderm and its derivatives, branchial arch epithelium, stomach, spleen, pancreas and liver, also showed efficient deletion. Our data suggest that the Nkx2-5IRESCre strain will be useful for genetic dissection of the multiple tiers of lineage allocation to the forming heart as well as of molecular interactions within the heart fields and heart tube.
KW - Conditional Gene Targeting
KW - Cre Recombinase
KW - Heart
KW - IRES
KW - Nkx2-5
UR - http://www.scopus.com/inward/record.url?scp=0036362978&partnerID=8YFLogxK
M3 - Article
C2 - 12141429
SN - 0214-6282
VL - 46
SP - 431
EP - 439
JO - International Journal of Developmental Biology
JF - International Journal of Developmental Biology
IS - 4 SPEC.
ER -