Cell cycle review from last week

Cell cycle review from last week - Cell cycle review from...

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Cell cycle review from last week Lee Hartwell logic of cell cycle high frequency light on yeast cells (mutaginized the yeast) isolate conditional mutants (temperature sensitivity in this case — ts alleles- they greq at 25degC and failed to grow at 37degC he looked at phenotypic morphology a mutant for cell cycle is a cell that fails to progress from 1 cell cycle stage to another (what was that ab bud size and stage of cell cycle?) he found mutants that stopped ne where in the cell cycle (problems w/ ribosomes and everything else involved in regulation of cell cycle) but if u stop at only a certain stage of the cycle, its unlikely to be random- its more likely that its something specific that’s wrong (synchronous arrest) then did a complementation test and finally epistasis to find out gene order and function from this he basically got a diagram for the cell cycle one of the major points is that one of the major proteins he discovered was cdc (cell division cycle mutants) 1 cdc is a kinase (it adds phosphate from an ATP to another protein- I think) this is the major protein involved in getting the cell cycle to start this same kinase regulates the cell cycle in pretty much everything up through humans (cdc is also known as cdk- cell division kinase?) His 2 nd experiment he asked, what determines the dependency relationships? (why does C depend on B or w/e?- i.e. how does the cycle work?) in G1 and G2 is protein synthesis and monitoring environment G2 checks for fidelity of the replication to do this, cell must tell cdk to stop until fidelity is checked and repairs are made if this doesn’t happen, the cell continues on through the cycle w/out checking and repairing damage! how do u discover this? take cells and mutagenize them w/ radiation to damage them and get rad mutants (conditional mutants depending on the condition of radiation they’re radiation sensitive) look at the phenotype (most of the rad mutants arrested as large budded we’re after S-phase in G2 checkpoint – this is good b/c ur stopping cell cycle b/c of damage but, some cells appeared as a large clump of uncontrolled growth (caused by the radiation damage – thus they fail to see the damage and thus didn’t arrest in G2 phase b/c of the damage) this was the key to developing the theory of cell cycle checkpoints, which
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This note was uploaded on 03/26/2008 for the course BIOL 202 taught by Professor Kieber-hogan during the Fall '08 term at UNC.

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Cell cycle review from last week - Cell cycle review from...

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