【摘要】 葡萄糖-6-磷酸脱氢酶是戊糖磷酸途径的限速酶,影响着细胞生命活动所需要的NADPH的产生。本研究从草菇中克隆到该基因的2个转录本,并测定了它们在两个同核体和形成的异核体菌株中的表达量。结果表明,草菇葡萄糖-6-磷酸脱氢酶基因(g6pdh)的g DNA序列长1 954bp,有7个内含子,可产生两个转录本:一个是内含子全部剪切的转录本(g6pdh ID),编码515个氨基酸且有完整结构域的蛋白质;另一个是第5个内含子保留的可变剪接变体(g6pdh IR),预测编码316个氨基酸但没有完整结构域的蛋白质。定量PCR结果显示,可变剪接变体g6pdh IR在草菇同核体与异核体中的表达量均很低,因此转录本g6pdh ID为g6pdh基因的主要剪接体;并且g6pdh基因在生长旺盛的异核体中的表达量远远高于在生长较弱的两个同核体中的任何一个。研究结论说明,糖代谢活动的强弱与食用真菌的生长与发育有密切关系。更多还原

【Abstract】 Glucose-6-phosphate dehydrogenase as rate-limiting enzyme in pentose phosphate pathway plays an important role in the production of NADPH being necessary to vital activities of cell. In this study, two transcripts of glucose-6-phosphate dehydrogenase encoding gene were cloned, and their expression levels were determined in homokaryon and heterokaryon strains of Volvariella volvacea, respectively. The results showed that g DNA sequence of g6 pdh spanning 1 954 bp contains seven introns, the fifth of them exists intron retention. Therefore, gene g6 pdh can produce two transcripts: one in which all introns were removed(g6pdh ID), encoding 515 aa glucose-6-phosphate dehydrogenase with integral conserved domain; another is alternative splicing variant with the fifth intron retention(g6pdh IR), encoding 316 aa presumptive protein without integral domain. The results of quantitative PCR showed that the expression levels of g6 pdh IR were extremely low in both homokaryon and heterokaryon strains, suggesting that g6 pdh ID was the main transcript of g6 pdh gene. The expression level of g6 pdh gene in rapid-growing heterokaryon strain was much higher than that in both of two slow-growing homokaryon strains. It is suggested that activity of glycometabolism may be involved in the growth and development of mushroom.更多还原