Cholangiocyte-specific Cre-recombinase transgenic mouse

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Cholangiocyte-specific Cre-recombinase transgenic
mouse

• Arthur Kaser
• Dept of Medicine II
• Innsbruck Medical University

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Background

• Conventional knock-outs
• Can be embryonically lethal
• Cant resolve divergent roles of single genes in
  different cell types
• Hepatocytes
• Cholangiocytes
• Immune cells

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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

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Conditional Gene deletion
Gene
loxP
loxP
Geneflox
Geneflox.CrePromoter
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Cre trangenic lines

• gt100 Cre transgenic mice reported so far
• Not a single one with reasonable specificity for
  cholangiocytes
• Indirect approaches
• Concomitant deletions in other organs/cell types

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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
• aGal-reporter mice
• Cre-reporter mice
• Generation of Cre-ERT2 mice under this promoter
• Intercrossing with mice expressing the floxed
  gene of interest

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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

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Implications

• Potential for in vivo dissection of mechanisms of
  disease
• Insight into novel loci identified through GWAS

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Precedence of transformative insight gained from
using Cre/loxP technology