1. MOSAIC ANALYSIS

2. MOSAIC ANALYSIS - WHY? Purposes of Mosaic Analysis
Examine later and/or tissue-specific functions of a gene required for viability
Bypass lethality to examine later function
Determine where gene function is required
Find which tissue is the source of gene activity
Determine “autonomy” of gene function
Cell lineage analysis

3. MOSAIC ANALYSIS – HOW? General Strategies for Mosaic Analysis
Nuclear or Cellular Transplantation
Mitotic Chromosomal Loss
Mitotic Recombination
Interchromosomal
Intrachromosomal

4. Mitotic Recombination
Must be induced (not normal)
DNA breaks (eg., X-rays)
Site-specific enzymes
FLP recombinase
Cre recombinase

5. FLP/FRT Targeted Mitotic Recombination
Recombination Step
MEK+
his-GFP
FRT
FLP
MEK-
FRT

6. FLP/FRT Targeted Mitotic Recombination
Segregation Option I: Outsides vs. Insides
MEK+/MEK-
green cells
MEK+
his-GFP
FRT
Segregation Option I: Outsides vs. Insides
MEK-
FRT
MEK+/MEK-
green cells

7. FLP/FRT Targeted Mitotic Recombination
Segregation Option II: Tops vs. Bottoms
MEK+/MEK+
green cells
MEK+
his-GFP
FRT
Segregation Option II: Tops vs. Bottoms
MEK-
FRT
MEK-/MEK-
white cells

9. Binary Expression System (GAL4/UAS)

10. Directed Mosaics

11. FLP/FRT-Mediated Mitotic Recombination (Intrachromosomal)

13. The “flp-out” cassette

14. Flp-out cassette to misexpress wingless

15. Binary Expression System (GAL4/UAS)

16. Flp-out clones with GFP marker

17. Expression by flp-out cassette

18. MARCM Scheme

19. MARCM dominant marking system

21. Mouse Mosaics: Cre/lox Recombination