These LSD1fl/fl mutant mice may be useful for studying the epigenetic mechanisms required for proper hematopoietic maturation, as well as the role of LSD1 in activity-evoked transcription of immediate early genes (IEGs) that impact memory formation, emotional behavior and information processing.
Stuart H Orkin, Harvard University
These LSD1fl/fl mice possess loxP sites flanking exons 5-6 of the lysine (K)-specific demethylase 1A (Kdm1a) gene. LSD1 demethylates histone H3 on Lys4 or Lys9 (H3K4/K9) and represses hematopoietic stem and progenitor cell (HSPC) gene expression during hematopoietic differentiation. Mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exons 5-6 deleted in the cre-expressing tissues.
For example, when bred to mice expressing Cre-recombinase in hematopoietic cells (see B6.Cg-Tg(Vav1-cre)A2Kio/J Stock No. 008610), double mutant mice die neonatally of severe anemia. Blood counts and bone marrow cellularity are reduced. Also, hematopoietic stem cells, multipotent progenitors, and myeloid progenitor cell numbers decreased 30-fold.
A targeting vector was designed to insert a single loxP site followed by a frt-flanked neomycin resistance (neo) cassette upstream of exon 5, and a second loxP site downstream of exon 6 of the lysine (K)-specific demethylase 1A (Kdm1a) gene. The construct was electroporated into 129Sv-derived CJ9 embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a Flp expression plasmid to delete the neo cassette. Resulting ES cells were injected into C57BL/6J blastocysts and resulting chimeric males were bred to C57BL/6J females. The donating investigator reported LSD1fl/fl mice were backcrossed to C57BL/6J mice for at least six generations (see SNP results below) prior to sending males to The Jackson Laboratory Repository in 2013. Upon arrival, males were used to cryopreserve sperm. To establish the living mouse colony, an aliquot of the frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).
In 2014, a 32 SNP (single nucleotide polymorphism) panel analysis, with 27 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 first generation rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 4 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest that the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.
|Allele Name||targeted mutation 1.1, Stuart Orkin|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Kdm1a, lysine (K)-specific demethylase 1A|
|Strain of Origin||129S1/Sv-Oca2+ Tyr+ Kitl+|
|Molecular Note||A targeting vector was designed to insert a single loxP site followed by a frt-flanked neomycin resistance (neo) cassette upstream of exon 5, and a second loxP site downstream of exon 6. Exons 5 and 6 encode a flavin adenine dinucleotide binding site and the N-terminal portion of the amine oxidase domain, both required for enzymatic activity. FLPe-mediated recombination removed the selection cassette.|
When maintaining a live colony, homozygous mice may be bred together.
When using the Lsd1fl mouse strain in a publication, please cite the originating article(s) and include JAX stock #023969 in your Materials and Methods section.