An article in “Nature” of 2009 appeared that research showed that per generation/per newly formed zygote 100 to 200 mutations are passed on, so mutations that are heritable ie in the germline.
Does our DNA mutate much faster than people have always thought? Seems like a high mutation rate to me.
Asker: Kathryn, 42 years old
Answer
Best,
Our DNA does not mutate faster than people have always thought. The average mutation frequency during DNA replication in eukaryotic cells is 1 per billion bases. Our cells contain 6 billion bases of DNA. So with each cell division about 6 mutations take place. To make an egg from the human zygote (embryo), about 30 cell divisions are needed. So in total 6 x 30 = 180 mutations per generation.
It should be noted that most of our DNA does not code for RNA or protein. Still, you would expect a mutational disaster scenario after many generations. The fact that this is not the case is probably due to the sexual recombinations that take place during gametogenesis.
Answered by
Prof. dr. dr. Luc Bouwens
Biomedical Sciences
Free University of Brussels
Avenue de la Plein 2 1050 Ixelles
http://www.vub.ac.be/
Avenue de la Plein 2 1050 Ixelles
http://www.vub.ac.be/
.