Grand challenge:Every disease requiresa tremendous amount
of interdisciplinaryeffort to understand
and fight it.Can this be streamlined?
The frequency of crossing-over is ~proportional to the physical distance between them.
Find DNA markers close to and flanking the gene of interest
Positional Cloning
• A chromosome has a single DNA molecule running the length of the chromosome
• Map the gene for the trait in question in that DNA molecule; identify close flanking markers
• “Walk” between the flanking markers• Identify the gene in question between the
markers
How do you map a gene?
• Collect DNA samples from family members in a pedigree
• Seek linkage to a polymorphic DNA marker
• Take advantage of the Human Genome Project to identify the chromosomal region
• Narrow down the location in the overlapping clones
What are “DNA markers”?
• RFLP--Restriction Fragment Length Polyhmorphism
• SNP--Single Nucleotide Polymorphisms
Mutation destroys a restriction site, causing a RFLP
(This is also a SNP--Single Nucleotide Polymorphism)
Top Related