DNA synthesis that occurs during repair is much less accurate than normal DNA replication. Using the yeast mating type switching system, Haber’s lab identified base pair substitutions, frame shifts and other mutations that occur when the newly synthesized strand dissociates from the template strand during homologous recombination. Interestingly, Haber found that sometimes the newly synthesized strand will “jump” to a related but divergent template, even on another chromosome, and then jump back to complete the repair. Further experiments showed that this happens because the repair polymerase falls off the template with a very high frequency. Understanding why this occurs may help us to decipher the complex chromosomal rearrangements associated with certain human diseases.
View the full talk with additional resources on our website
Broken Chromosome Repair by Homologous Recombination
Broken chromosomes naturally arise during DNA replication. In healthy cells, the breaks are repaired by homologous recombination. If the repair machinery is broken, cancer can result. (Talk recorded in October 2018)
- Part 1: Broken Chromosome Repair by Homologous RecombinationAudience:
- Student
- Researcher
- Educators of H. School / Intro Undergrad
- Educators of Adv. Undergrad / Grad
Duration: 00:35:59 - Part 2: Molecular Mechanisms of Repairing a Broken ChromosomeAudience:
- Student
- Researcher
- Educators of H. School / Intro Undergrad
- Educators of Adv. Undergrad / Grad
Duration: 00:33:14 - Part 3: Mutations Arising during Repair of a Broken ChromosomeAudience:
- Student
- Researcher
- Educators
- Educators of H. School / Intro Undergrad
- Educators of Adv. Undergrad / Grad
Duration: 00:23:01