STOCK Hand1^{tm1.1(EGFP/cre)Abfi}/J

Stock number: 025870
Product name: Hand1^EGFPCreΔneo knock-in/knock-out
Research areas: Cardiovascular Research, Developmental Biology Research, Internal/Organ Research, Research Tools

Description

Hand1^EGFPCreΔneo KO mice express EGFP and cre from the Hand1 promoter making them useful for studying the development of the heart, neural crest, brachial arch, and yolk sac, as well as vascular development of the left ventricle.

Detailed description

The initiation codon of the heart and neural crest derivatives expressed transcript 1 (Hand1) gene with an EGFP and cre fusion protein, abolishing gene expression. HAND1 is a basic helix-loop-helix transcription factor expressed in the developing left ventricle and cadiac outflow tract and plays an essential role in cardiac morphogenesis. Heterozygous mice are viable and fertile, while homozygotes die between E8.5 and E9.5 due to defects in heart, extraembryonic mesoderm, and yolk sac development. When Hand1 expression is present, EGFP immunofluorescence is observed in specific lineages within the extra embryonic tissues, placenta, sympathetic nervous system, limbs, jaw, cardiac outflow tract and left ventricular myocardial calls in the heart. When Hand1^EGFPCreΔneo KO mice are crossed with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the Hand1-expressing cells of the offspring.

When Hand1^EGFPCreΔneo KO mice are crossed with ROSA 26 reporter mice, Hand1 cell-lineage contributions are observed in the above mentioned tissues, as well as the epicardium of the heart. No significant contributions of Hand1 lineage cells are observd within the endocardium or right ventricular myocardium.

Development

A targeting vector was designed to replace the initiation codon of the heart and neural crest derivatives expressed transcript 1 (Hand1) gene with an enhanced green fluorescent protein fused to a Cre Recombinase sequence, followed by a frt-flanked neomycin resistance cassette. The construct was electroporated into 129S/SvEv-derived CCE916 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and the resulting chimeric males were bred to 129S4/SvJaeSor-Gt(ROSA)26Sor^tm1(FLP1)Dym/J mice (Stock No. 003946) to delete the neo cassette and progeny were crossed to remove the frt-expressing transgene. These mice were bred to Black Swiss mice and were subsequently maintained on a mixed background. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Hand1^{tm1.1(EGFP/cre)Abfi}
Name: targeted mutation 1.1, Anthony B Firulli
MGI accession ID: MGI:4838016
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Hand1
Marker name: heart and neural crest derivatives expressed 1
Chromosome: 11
Strain of origin: 129S/SvEv
Expressed genes: GFP/cre,Green Fluorescent Protein/Cre recombinase fusion protein,
Site of expression: In mice carrying this allele EGFP is expressed within the extra embryonic tissues, placenta, sympathetic nervous system, limbs, jaw, cardiac outflow tract and left ventricular myocardial calls in the heart.
Molecular note: A targeting vector containing a 3.4 kb EGFP/cre cassette with a 3' Frt-flanked neomycin cassette was introduced into the 5' untranslated region of Hand1. Homologous recombination resulted in deletion of the first exon of Hand1, producing a null allele, and insertion of the EGFP/cre gene under control of the endogenous promoter. Following germline transmission, the neo cassette was deleted by crossing mice to FLPeR homozygous mice.