STOCK Myf5^tm1Pas/J

Stock number: 018626
Research areas: Developmental Biology Research, Neurobiology Research, Research Tools

Description

This Myf5-nlacZ knock in strain expresses lacZ under the direction of the endogenous Myf5, myogenic factor 5, promoter with beta-galactosidase activity detected in muscle progenitor cell lineages. Applications exist in studies related to myogenesis and neurogenesis.

Detailed description

Myf5, myogenic factor 5, is a basic Helix-Loop-Helix transcription factor involved in muscle cell differentiation. These mice carry a targeted mutation in which a beta-galactosidase gene (lacZ) with a nuclear localization signal disrupts the bHLH domain of the protein. Beta galactosidase activity mimics the endogenous expression pattern of the Myf5 gene, and is detected as early as embryonic day 9 in the caudal myotomes and embryonic day 8 in newly differentiated neurons in the mesencephalon. Mice that are heterozygous for the targeted mutation are viable and fertile. Homozygotes die soon after birth due to respiratory failure. Homozygotes also exhibit delayed myotome formation and truncated ribs. No gene product (mRNA) is detected by in situ hybridization analysis of homozygous embryos. Expression of the adjacent Myf6, myogenic factor 6, is not detected by RT-PCR of skeletal muscle from homozygotes, or by whole mount in situ hybridization of homozygous embryos. This strain serves as a reporter for marking cells in the myogenic lineage and for adult muscle stem (satellite) cells.

Development

A targeting vector was used to fuse nlacZ gene (beta-galactosidase gene (lacZ) with a nuclear localization signal) and a tk-NEO cassette in frame into the first exon, 13 amino acids following the ATG codon, disrupting the gene by deleting the bHLH domain (amino acids 14-122). The construct was electroporated into 129S2/SvPas derived D3 embryonic stem (ES) cells. Correctly targeted ES cells were injected into (C57B16 x SJL)F1 2.5 day precompaction morula. The mice were crossed to C57BL/6 and DBA2 mice. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

Allele

Symbol: Myf5^tm1Pas
Name: targeted mutation 1, Institut Pasteur
MGI accession ID: MGI:1857973
Generation method: Targeted
Attributes: Reporter
Marker symbol: Myf5
Marker name: myogenic factor 5
Chromosome: 10
Strain of origin: Not Specified
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: Myf5 is a basic Helix-Loop-Helix transcription factor involved in muscle cell differentiation.
Molecular note: An nLacZ gene is fused in-frame to the DNA sequences encoding the first 13 amino acids, resulting in a disruption of the gene and expression of nLacZ under the transcriptional regulation of the endogenous promoter. A neomycin resistance cassette, RNA polymerase II promoter and 3' sequence of the HPRT gene were introduced after the reporter gene.