饰变指不涉及遗传物质结构改变而只发生在转录 转译水平上的表型变化。 diobacter grown on two different media. Left: Mucoid colonies on sucrose-salts medium: right: non- mucoid colonies on trypticase-soy 饰变的点 agar medium 整个群体中的九乎每一个体都发生同 u: 12:2. Morphological modi- icat:ons (phenotypic changes)re- sulting from changes in media phase-contrast micrographs of No- cardia sp, in (A) tryptone agar culture: (B) brain-heart infusion gar: both cu 2hat3o° C curtesy of B, L. Beaman and D 因得物质不变解受是延传的 M. Shankel, and / Bacteriol 99:B76,.1969.)(C)andD)are electron micrographs of thin sec- tions of Arthrobacter globiformis 425 grown in (C) nutritionally deficient medium resulting in ab- normal forms of the bacterium (several protoplasts embedded in an amorphous matrix). Note that the aberrant cells are devoid of cell walls and no longer exhibit the typical shape of the species as 参 shown in (C). Incubation was at 25 C for 36 h. ( Courtesy of Mar- garer Gomersall and E. c. s Chan.饰变 指不涉及遗传物质结构改变而只发生在转录、 转译水平上的表型变化。 饰变的特点： ▪整个群体中的几乎每一个体都发生同样变化； ▪性状变化的幅度小； ▪因遗传物质不变，故饰变是不遗传的；