BIOL355 Lecture Notes - Lecture 19: Non-Homologous End Joining, Calorie Restriction, Depurination
21 Apr 2017
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Lecture 19: radiation exposure (animal systems) leads to increased mutations of dna and decreased. Increasing mutation levels, increasing mutation rates as animals age. Evidence that mutations in dna can lead to altered proteins and diseases such as cancer etc: changes in dna (somatic or germ) can cause loss of function in proteins or abnormal functioning proteins. Intrinsic sources such as ros, spontaneous chemical reactions and extrinsic sources such as chemicals and radiations leads to dna damage (ex; strand breaks, depurination and deamination) Dna repair pathways (eg; ber, ner, nhej) influence dna damage. Dna damage can lead to mutations, cell cycle arrest, transcription impairment, gene expression dysregulation, apoptosis etc. This leads to cell loss and cellular dysfunction. Causes stem cell depletion and disruption of tissue homeostasis. Chromatograms of dna taken from liver and kidney of male rats show that six or more modified bases (l-spots) increase in amount as the rats age through 10 months (early middle age)
