FVB.129P2(B6)-Mmp14^tm2Ski/MbisJ

Stock number: 030933
Product name: MT1-MMP^lacZ knock-in/knock-out (FVB.MT1-MMP^lacZ)
Research areas: Cancer Research, Cell Biology Research, Developmental Biology Research, Endocrine Deficiency Research, Internal/Organ Research, Research Tools

Description

The MT1-MMP^lacZ knock-in/knock-out allele was designed to both abolish Mmp14 gene function and express a NLS-lacZ cassette. These mice are useful as a knock-in for mapping MMP14 expression, and useful as a knock-out for studying branching morphogenesis and cellular invasion in cancer, as well as metabolism, homeostasis and autophagy.

Detailed description

The cell membrane-bound matrix metalloproteinase MMP14 is involved broadly in organ development through both its proteolytic and signal-transducing functions. MMP14 functions in branching morphogenesis, and is known to have a key role in cancer cell invasion. MMP14 activity is also associated with maintaining tissue metabolism/homeostasis.

The MT1-MMP^lacZ knock-in/knock-out allele has a β-galactosidase with nuclear-localization tag (NLS-lacZ) replacing the exons encoding the pro- and catalytic domains (exons 1-5) of the Mmp14 locus. This abolishes endogenous gene function and results in the Mmp14 promoter/enhancer regions directing NLS-lacZ expression.

MT1-MMP^lacZ heterozygotes (Mmp14 (+/lacZ)) are viable and fertile with normal development. MT1-MMP^lacZ homozygotes (Mmp14 (lacZ/lacZ)) die by ~10-15 days old with reduced body size and wasting phenotype. Compared with wildtype, the MMP14-deficient mammary glands show reduced ductal elongation, branching intervals and branching points. Additionally, the donating investigator reports that homozygous mice exhibit defective collagen turnover which results in craniofacial dysmorphism, osteopenia, arthritis, fibrosis in soft tissue and dwarfism. Homozygotes also show impaired adipogenesis (less adipose tissues of skin and mammary fad pad). In general, homozygous females may survive a few days longer than homozygous males.

MT1-MMP^lacZ mice are available backcrossed onto the C57BL/6J genetic background (B6J.MT1-MMP^lacZ; Stock No. 030905) and backcrossed onto the FVB/NJ genetic background (FVB.MT1-MMP^lacZ; Stock No. 030933). The donating investigator summarizes the similarities/differences between the two strains as described below. MT1-MMP^lacZ mice on both genetic backgrounds exhibit similar lacZ expression patterns, as well as similar MMP14 distribution in the mammary gland (no difference in the levels of protein and number/distribution of positive cells). B6J.MT1-MMP^lacZ homozygotes exhibit more severe dwarfism and have less adipose tissue at 10-14 days of age. FVB.MT1-MMP^lacZ homozygous death is a bit earlier.

Development

The MT1-MMP^lacZ knock-in/knock-out allele was created in the laboratory of Dr. Motoharu Seiki (University of Tokyo). A targeting vector was designed to replace exons 1-5 of the matrix metallopeptidase 14 (membrane-inserted) locus (Mmp14) on chromosome 14 with a β-galactosidase gene with nuclear localization signal (NLS-lacZ) followed by a reverse-orientated PGK-gpt/neo cassette (composed of a PGK promoter, guanine phosphoribosyl transferase gene, thymidine kinase promoter and neomycin resistance gene). The construct was electroporated into 129P2/OlaHsd-derived E14 embryonic stem (ES) cells, and correctly targeted ES cells were injected into recipient blastocysts. Chimeric animals were bred with C57BL/6JJcl for germline transmission. The MT1-MMP^lacZ colony was backcrossed to C57BL/6JJcl inbred mice at least six generations. Mice from that B6JJcl.MT1-MMP^lacZ colony were sent to Dr. Mina J. Bissell (Lawrence Berkeley National Laboratory).
There, some B6JJcl.MT1-MMP^lacZ mice were backcrossed to FVB/NJ inbred mice at least six generations. Heterozygous males (albino) from that FVB.MT1-MMP^lacZ colony were sent to The Jackson Laboratory Repository in 2017 as Stock No. 030933. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize FVB/NJ oocytes (Stock No. 001800).
Of note, the donating investigator reports that, at least once during backcrossing, a MT1-MMP^lacZ female was bred to a FVB/NJ inbred male (thus the Y chromosome of the congenic strain is of FVB/NJ origin).

Allele

Symbol: Mmp14^tm2Ski
Name: targeted mutation 2, Motoharu Seiki
MGI accession ID: MGI:3720698
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Synonyms: MT1-MMP^lacZ
Marker symbol: Mmp14
Marker name: matrix metallopeptidase 14 (membrane-inserted)
Marker synonyms: Membrane type 1-MMP; MMP-14; MMP-X1; MT1MMP; Mt1-mmp; MT-MMP; MT-MMP 1; MTMMP1; sabe; WNCHRS
Chromosome: 14
Strain of origin: 129P2/OlaHsd
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: Vascular expression in vivo is confined largely to the sprouting tip of neocapillary structures where endothelial cell proliferation and collagen degradation are coordinately localized
Molecular note: The NLS-lacZ cassette replaced exons 1-5, which encode the pro- and catalytic domains.