IMED2004 Study Guide - Final Guide: Dna Replication, Meiosis, Sister Chromatids
Document Summary
Is a form of mutation that leads to either a trinucleotide or dinucleotide expansion or contraction during dna replication. If loop occurs in template strand during replication, dna polymerase misses looped out nucleotides, and small insertions and deletions occur. = new (nascent) dna strand from pale blue template. New strand has more repeat units or. Unstable due to nature or repetitive seq. = nascent strand during replication can partially dissociate from template strand and re-associate. During re-association, there can be misalignment of the repeat seq. End up with insertion of second ca repeat (expansion of microsatellite) Diagram is insertion of 1 repeat but in reality can be many. = end up with deletions in one of the repeats. Misaligned chromatids can be on homologous chromosomes (uec) Result in change in copy number repeats in chr. Unequal crossing over between blue and green.
