Mcm2IRES-EGFP mice have an enhanced green fluorescent protein (EGFP) sequence inserted downstream of the stop codon of the minichromosome maintenance deficient 2 mitotin (Mcm2) gene. Mcm2 expression from the Mcm2IRES-EGFP mutant allele is normal (as determined by Northern blots and immunological tests).
Homozygous Mcm2IRES-EGFP mice are viable, fertile, normal in size, and do not display any gross physical or behavioral abnormalities. EGFP expression is seen in regions known to be highly proliferative; including spleen, small intestine, colon, and hair follicles. EGFP expression is also detectable in the majority of bone marrow and in slowly-cycling neural stem cells in the subventricular zone of the brain.
Mcm2 is a component of the DNA replication licensing complex expressed in stem/progenitor cells in a variety of regenerative tissues. Mcm2 plays an essential role in eukaryotic cell division as it marks DNA replication origins during G1 for use in the subsequent S-phase. MCM2 prevents multiple rounds of replication from a single origin and suppresses endoreduplication. Mice harboring other mutations resulting in reduced Mcm2 expression exhibit highly penetrant early onset cancers and stem cell deficiencies. These Mcm2IRES-EGFP mice may be useful for visualizing and recovering proliferation competent cells.
