Some required events in conidial germination of Neurospora crassa☆

[摘要] Atemperature-sensitivemutantofNeurosporacrassa,withreducedlevelsofproteinsynthesisat37°C,wasusedtoidentifysomeessentialeventsinconidialgermination.Conidiaofmutantstrainpsi-1wereincubatedfor2hrat37°Candthenshiftedto20°C.Germinationwasinhibitedat37°C,butcommencedafter1.5hrat20°C.Increasesinaspartatetranscarbamylaseactivity,cellwallsynthesis,andnuclearnumberprecededgermination.However,increasesinglutamatedehydrogenaseactivity,aminoaciduptake,andDNAsynthesiswereinhibitedpriortogermination.Althoughalloftheseeventswerecorrelatedwithgerminationincontrolculturesofthemutantat20°Candofitsparentstrainat20and37°C,someeventswereapparentlynotessentialforgermination.Therequirementforaspartatetranscarbamylaseactivitywasdemonstratedindependentlybythefailureofstrainpyr-3d(lackingtheactivity)togerminateintheabsenceofuridine.ThedispensabilityofglutamatedehydrogenaseactivityandDNAsynthesisforthegerminationofsomeconidiawasverifiedbythegerminationofstrainam-1(lackingglutamatedehydrogenaseactivity)intheabsenceofglutamateandbythegerminationoftheparentstraininthepresenceofhydroxyurea(aninhibitorofDNAsynthesis).Thesefindingsidentifysomelandmarksingerminationwhichmaybeusefulinfurtherstudiesoftheregulationofadevelopmentalprogram.Theyalsoprovidepreliminaryevidencethattherestingconidiamaycontainnucleiarrestedatdifferentstagesoftheirdivisioncycle.

[学科分类] 生物科学（综合）