Szabo Roman, Stofaníková Veronika
Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Mlynska dolina CH-1, 842 15, Bratislava, Slovak Republic.
FEMS Microbiol Lett. 2002 Jan 2;206(1):45-50. doi: 10.1111/j.1574-6968.2002.tb10984.x.
Yeast dimorphism is an attractive model for the study of cell morphogenesis and differentiation. The non-conventional yeast Yarrowia lipolytica was chosen to characterise the regulation of dimorphic transition by extracellular pH and by the presence of organic sources of nitrogen. Organic nitrogen sources appear to be required for the morphogenic effect of pH. Two sets of mutants defective in either pH-dependent or nitrogen source-dependent signalling pathway were analysed. The results suggest that the latter but not the former is required for both normal filament formation on solid medium and pH-dependent dimorphic behaviour of Y. lipolytica in liquid medium. We propose that in this organism pH affects the formation of hyphae indirectly by modulation of availability and/or utilisation of transportable sources of nitrogen.
酵母二态性是研究细胞形态发生和分化的一个有吸引力的模型。选用非常规酵母解脂耶氏酵母来表征细胞外pH值和有机氮源的存在对二态转变的调节作用。有机氮源似乎是pH值形态发生效应所必需的。分析了两组分别在pH依赖或氮源依赖信号通路中存在缺陷的突变体。结果表明，后者而非前者对于在固体培养基上正常形成菌丝以及解脂耶氏酵母在液体培养基中的pH依赖二态行为都是必需的。我们提出，在这种生物体中，pH值通过调节可转运氮源的可用性和/或利用来间接影响菌丝的形成。
