DNA Fingerprinting Flashcards
What are microsatellites?
Repetitive DNA regions with high mutation rate and therefore high diversity in populations. Tandem repeats of short DNA fragments (2-5bp).
How are microsatellites used in cancer diagnosis?
Microsatellites may be lost or gained rapidly in tumour cells during mitosis so tumour cells might show different genetic fingerprints to normal host cells.
How are microsatellites used in genetic linkage analysis?
Scan to locate any genes responsible for a given phenotype or disease. Used to discover Type II diabetes and prostate cancer genes.
How are microsatellites used in wildlife forensics?
They can reduce illegal trafficking of flora and fauna by supporting wildlife crime investigations.
Describe a molecular marker.
A genetic difference that is not the target gene.
Does not affect target phenotype.
All markers occupy loci.
What is an amplified fragment length polymorphism (AFLP)?
A PCR-based technique that uses selective amplification of a subset of digested DNA fragments to generate and compare unique fingerprints for genomes of interest.
What are the benefits of using amplified fragment length polymorphisms (AFLPs)?
No prior information is needed regarding the targeted genome.
High reproducibility.
High sensitivity.
What do linkage maps involved?
Markers being mapped into groupings according to chromosomes using software.
What are quantitative trait loci (QTLs)?
Genomic regions that are associated with effects on quantitative regions.
What is required for quantitative trait loci mapping?
1) A saturated linkage map.
2) Reliable phenotypic screening.
3) A suitable population generated from contrasting parents.
What is the output from quantitative trait loci mapping and what does it mean?
A LOD score - logarithm of odds. This is the chance of a trait/marker being linked. LOD = 3 means a 1 in a 1000 chance.
