BIO 325 Lecture Notes - Lecture 7: Mobile Genetic Elements, Tandem Repeat, Dna Mismatch Repair
Document Summary
Methyl-directed mismatched repair corrects recently replicated dna: can tell old from new strand because old one is methylated, tear out unmethylated strand. Unequal crossing over creates one homologous chromosome with a duplication and one with a deletion. Happens when genes in tandem have similar sequence. Fragile x associated mental retardation: repeats of a bunch of sequences in a row, the more repeats you have the more likely you will have more repeats --> fragile x, caused by dna polymerase slippage. Mutagens induce mutations: mutagens can be used to increase mutation rates, muller - first discovered x rays increase mutation rate. The ames test: got cells that require his to live, take mutagen, treat bacteria with mutagen, if increase in mutation, increase in revertants; put bacteria in dish without his --> if they survive, they have reverted. Complementation test used to see whether mutations are in different genes. If cross two (recessive) mutants and get mutant, in same gene.
