Use of Markers
Scenario
There are approximately 3 billion base pairs of DNA in the human genome. Only ~1% of this genome can be characterized as ‘gene’ or ‘protein coding’, which leaves 99% mainly unaccountable. Previously termed ‘Junk DNA’ (non-coding DNA is a slightly friendlier term), this 99% is becoming more and more important as research continues, and we now know that this non-coding DNA is composed of regulatory sequences, introns, pseudogenes, and repeat sequences. It is in these repeat sequences where we can find the variability between individuals that can lead to a positive identification. But where in this 99% to look? This is where DNA markers can be utilised.
The following questions will test your research skills and your understanding of the use of different DNA markers. You should use in-text referencing where appropriate.
1. Compare and contrast VNTRs and STRs with respect to forensic science.
2. Using your research skills, produce a table showing the loci that are currently amplified using DNA-17. You should also include the chromosomal location and sequence of the loci. The correct format should be used.
3. Using your knowledge of Population Genetics and Linkage Disequilibrium, discuss the importance of using marker SE33 when carrying out DNA profiling.
