Science Buddies: "Ask an Expert"

Hi,
Is there a difference between photolesions (pyrimidine dimers) and SNPs? If so, what is the difference and are they related?

Thanks,
blueswim

A SNP is a single nucleotide polymorphism - meaning a single change in the DNA code that is usually genetically heritable. These aren't necessarily mutations. Pyrimidine dimers are a result of DNA damage (ie, from UV light). While cells have the ability to repair DNA damage, if these pyrimidine dimers are repaired to a nucleotide that does not match the parental, or non-damaged, strand, this will lead to mutations. Some of these mutations can be benign, but some can lead to disease, most commonly as a result of UV-induced DNA damage would be skin cancer. Since these types of mutations are rarely in the germ cells (sperm and eggs) they would not be genetically heritable.

I found this SNP: http://www.ncbi.nlm.nih.gov/projects/SN ... =121434641
And I was researching pyrimidine dimers, and sources said that the cyclobutane pyrimidine dimers were changes from C-> G, which is what this SNP is also (and also caused by UV light).
And it doesn't seem to be inherited.
Could it be the cyclobutane pyrimidine dimer is this SNP? Or is it a crazy idea?

Thanks, blueswim

Hi-
Since it's not heritable, I don't think it could be called a SNP.

Stephanie