Caprioglio D R, Parks L W
Department of Microbiology, North Carolina State University, Raleigh 27695-7615.
J Bacteriol. 1989 Sep;171(9):4876-80. doi: 10.1128/jb.171.9.4876-4880.1989.
Wild-type cultures of Scytalidium flavo-brunneum produce a 15-azasterol antifungal agent and a reddish brown pigment as secondary metabolites. Spontaneous mutants of S. flavo-brunneum that had simultaneously lost the ability to produce the 15-azasterol and the pigment were transformed with plasmid pSFB-1, which was obtained from wild-type S. flavo-brunneum. Each transformant possessed the plasmid and coincidentally reacquired azasterol and pigment production. Regulation of transcription and relative plasmid copy number was determined as a function of the culture cycle of the organism. Twenty-five-fold amplification of the plasmid was observed in the fungus during the stationary phase. RNA transcripts of 0.9, 1.0, 1.5, 2.0, and 2.5 kilobases were expressed from the plasmid by the organism. While differences in the temporal regulation of the transcripts were seen, all except the 1.0-kilobase transcript increased in abundance on entry of the culture into the stationary phase of growth.
黄褐丝葚霉的野生型培养物产生一种15-氮杂甾醇抗真菌剂和一种红棕色色素作为次生代谢产物。同时丧失产生15-氮杂甾醇和色素能力的黄褐丝葚霉自发突变体用从野生型黄褐丝葚霉获得的质粒pSFB-1进行转化。每个转化体都拥有该质粒，并且巧合地重新获得了氮杂甾醇和色素的产生能力。转录调控和相对质粒拷贝数是作为生物体培养周期的函数来确定的。在静止期观察到真菌中质粒有25倍的扩增。该生物体从质粒表达了0.9、1.0、1.5、2.0和2.5千碱基的RNA转录本。虽然观察到转录本在时间调控上存在差异，但除了1.0千碱基的转录本外，所有转录本在培养进入生长静止期时丰度都增加了。
