Download Kaser_Cholangiocyte-Cre

Cholangiocyte-specific Crerecombinase transgenic mouse
Arthur Kaser
Dept of Medicine II
Innsbruck Medical University
Background
• Conventional knock-outs
▫ Can be embryonically lethal
▫ Can‘t resolve divergent roles of single genes in
different cell types
 Hepatocytes
 Cholangiocytes
 Immune cells
Cre/loxP technology
• Allows specific deletion of genes in a living
organism
• Cre recombinase recognizes specific ‚loxP‘
sequence...
• ...excises the DNA in-between two loxP sites and
recombines the flanking stretches of DNA
Conditional Gene deletion
Gene
loxP
Geneflox
Geneflox.CrePromoter
loxP
Cre trangenic lines
• >100 Cre transgenic mice reported so far
• Not a single one with reasonable specificity for
cholangiocytes
▫ Indirect approaches
▫ Concomitant deletions in other organs/cell types
Process
• Identification of a cholangiocyte-specific promoter
▫ Candidate genes
▫ Bio-informatic analysis of cholangiocyte cell lines and
primary cholangiocytes
• In vivo evaluation of promoter specificity
▫ αGal-reporter mice
▫ Cre-reporter mice
• Generation of Cre-ERT2 mice under this promoter
• Intercrossing with mice expressing the floxed gene
of interest
Issues
• Fundamental
▫ Can a cholangiocyte-specific promoter be
identified?
▫ Target large or small cholangiocytes, or both?
• Technical
▫ How many reporter mice shall be generated?
▫ Where shall those be generated?
 Commercial vendors
 Academic group(s)
▫ Sharing policy
Implications
• Potential for in vivo dissection of mechanisms of
disease
• Insight into novel loci identified through GWAS
Precedence of transformative insight
gained from using Cre/loxP technology