Properties of yeastGrowas haploid ordiploid organismsCan identify recessive mutations in haploidsComplementation analysisindiploidsBudding-daughtercell arises on the surface of mothercelland grows in size during cell cycle. Helps determine stage ofcell cyclePowerful geneticsMG1G1/SS/G2G2/MTubulinandnucleusActin19-11
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 19-11 Properties of yeast Properties of yeast Grow as haploid or diploid organisms Grow as haploid or diploid organisms Can identify recessive mutations in haploids Can identify recessive mutations in haploids Complementation analysis in diploids Complementation analysis in diploids Budding Budding – daughter cell arises on the surface of mother cell daughter cell arises on the surface of mother cell and grows in size during cell cycl and grows in size during cell cycle. Helps determine stage of e. Helps determine stage of cell cycle cell cycle Powerful genetics Powerful genetics
The 2001 Nobel Prize in Physiology or MedicineTim HuntLelandH.HartwellPaul M. NurseFound cdc2Found cyclinsIsolated cell divisioncyclecdcmutantsinthefissionyeastin sea urchininthebuddingyeast19-12
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 19-12 The 2001 Nobel Prize in Physiology or Medicine Leland H. Hartwell Isolated cell division cycle cdc mutants in the budding yeast Paul M. Nurse Found cdc2 in the fission yeast Tim Hunt Found cyclins in sea urchin
Isolation of temperature-sensitive mutants in yeastHaploid cellstreatedMutants grow normally atwithmutagen.permissive temperature,but lose gene function atDiluteandspreadsinglecellsonnutrientrestrictive temperature.plateat22°C(permissivetemperature)Several dozens of cell cyclemutantshave been isolatedAllowcellstogrowintocolonies.Imprintcoloniesontotwoplates.店Growat22°CGrowat36°CTemperature-sensitive-mutantLeland H.Hartwell
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 19-13 Isolation of temperature Isolation of temperature-sensitive mutants in yeast sensitive mutants in yeast Mutants grow normally at Mutants grow normally at permissive temperature, permissive temperature, but lose gene function at but lose gene function at restrictive temperature. restrictive temperature. Several dozens of cell cycle Several dozens of cell cycle mutants have been isolated. mutants have been isolated. Leland H. Hartwell
A cell-cycle mutant of yeast(a)Growth atpermissivetemperature displays budsof all sizes.(b)Growth at restrictivetemperature shows cellsarrested with a large bud19-14Fig
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 19-14 A cell-cycle mutant of yeast cycle mutant of yeast (a) Growth at permissive (a) Growth at permissive temperature displays buds temperature displays buds of all sizes. of all sizes. (b) Growth at restrictive (b) Growth at restrictive temperature shows cells temperature shows cells arrested with a large bud. arrested with a large bud. Fig. A
Wild-type and cdc mutant cells several hours afterincubation at the restrictive temperatureAWild-typecdc8cdc10cdc24FigurefromLeeHartwell19-15
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 19-15 Wild-type and cdc mutant cells several hours after incubation at the restrictive temperature Wild-type cdc8 cdc24 cdc10 Figure from Lee Hartwell