STOCK Kmt2d^tm1.1Kaig/J

Stock number: 032152
Product name: Mll4^f
Research areas: Cardiovascular Research, Cell Biology Research, Research Tools

Description

Mll4^f/f mice possess loxP sites flanking exons 16-19 of the lysine (K)-specific methyltransferase 2D (Kmt2d) gene. These floxed mice are useful for tissue specific deletion of Kmt2d when studying the role of histone H3 lysine 4 di-methylation in development and the onset of certain cancers.

Detailed description

Mll4^f/f mice possess loxP sites flanking exons 16-19 of the lysine (K)-specific methyltransferase 2D (Kmt2d) gene. KMT2D is widely expressed in adult tissues and is essential for in regulating development, differentiation, metabolism, and tumor suppression. Mutations in KMT2D are associated with developmental diseases such as Kabuki syndrome and congenital heart disease, and various forms of cancer. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exons 16-19 deleted in the cre-expressing tissues. Removal of the floxed exons causes an open reading frame shift and creates a stop codon in exon 20, which leads to the creation of a truncated MLL4 protein lacking the C-terminal ~4200aa.

Homozygous mice are viable and fertile. In 2019, colonists at The Jackson Laboratory found that pups from homozygous matings are severely runted. The donating investigator reports that this may be due to a decrease in Kmt2d gene expression caused by the insertion of loxP sites. When maintaining a live colony, heterozygous mice may be bred together to produce healthy homozygous offspring. Alternatively, heterozygous females can be bred to homozygous males. It is unknown at this time if offspring from homozygous females bred to heterozygous males are runted.

Development

The Mll4^f targeting vector was designed to insert a loxP site upstream of exon 16, and a frt-flanked neomycin selection cassette, followed by a second loxP site, downstream of exon 19 of the lysine (K)-specific methyltransferase 2D (Kmt2d) gene. The construct was electroporated into embryonic stem (ES) cells. Resulting ES cells were injected into blastocysts and resulting Mll4^floxneo/+ males were bred to C57BL/6J females. Subsequently, mice were bred to ROSA26::FLPe mice (Stock No. 003946) to remove the neo cassette. Progeny were crossed to remove the Flp-expressing transgene, and offspring were bred to C57BL/6J mice by the donating lab (see SNP note below). Frozen sperm were shipped to The Jackson Laboratory Repository. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

A 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. Twelve of the 43 markers throughout the genome were segregating, suggesting an incomplete backcross.

Allele

Symbol: Kmt2d^tm1.1Kaig
Name: targeted mutation 1.1, Kai Ge
MGI accession ID: MGI:5585624
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Mll4^f
Marker symbol: Kmt2d
Marker name: lysine (K)-specific methyltransferase 2D
Marker synonyms: AAD10; ALR; bapa; BCAHH; C430014K11Rik; CAGL114; KABUK1; KMS; Mll2; Mll4; TNRC21
Chromosome: 15
Strain of origin: Not Specified
Molecular note: A loxP site was inserted upstream of exon 16. An FRT-flanked neomycin resistance cassette with a 3 loxP site was inserted downstream of exon 19. Flp-mediated recombination removed the selection cassette and left exons 16 through 19 floxed.