floxed - 'flanked by loxP sites'
A 'floxed' gene is one that has engineered 'LoxP' recombination sites on the left and right ('flanking'). When the Cre recombinase protein is expressed, the Lox sites recombine to either remove the DNA between them (Lox sites in same orientation) or invert the segment of DNA (Lox sites in opposite orientations). In the first case, this makes a deletion allele of the gene in question - but only in the cells expressing the Cre protein. (For example, this can be used to avoid a lethal phenotype in a regular homozygous deletion mutant. Or, to study the mutant phenotype in only a specific tissue.) The Cre recombinase protein can be turned on in specific cell or tissue types. In this paper, Cre recombinase protein is induced (expression turned on) by beta-naphthoflavone injection.
An article explaning the Cre-Lox transgenics system: Mouse Cre/loxP system: general principles to determine tissue-specific roles of target genes
The Wikipedia entry is pretty good: floxed
The Cre-Lox and Flp-Frt systems from Jackson Labs.
BrdU (BromodeoxyUridine) - a thymidine analog that is taken up and inserted into DNA like 'T' during S phase. The BrdU in cells can be detected with a specific antibody agains BrdU. 'BrdU incorporation' is a measure of how many cells are proliferating (that is, in S phase). Such cells may be referred to as 'BrdU positive' cells.
Ki67 - a Ki67 antibody marks a nuclear protein found only in proliferating cells and not in quiescent cells. So, it provides similar information to BrdU.
IHC - immunohistochemistry - here, using an antibody to a given protein, then an enzyme-linked secondary antibody. The enzyme substrate DAB makes a dark brown precipitate indicating presence of the protein of interest (i.e., b-catenin, c-Myc, Ki67)
Microarray analysis here involves comparing RNA expression levels from many genes in different genotypes.