VISUALIZATION OF DIFFERENTIAL GENE-EXPRESSION USING A NOVEL METHOD OFRNA FINGERPRINTING BASED ON AFLP - ANALYSIS OF GENE-EXPRESSION DURINGPOTATO-TUBER DEVELOPMENT

Using a highly synchronous in vitro tuberization system, in combinatio n with an amplified restriction fragment polymorphism (AFLP dagger-der ived technique for RNA fingerprinting (cDNA-AFLP double dagger), trans criptional changes at and around the time point of potato tuberization have been analyzed. The targeted expression analysis of a specific tr anscript coding for the major potato storage protein, patatin and a se cond transcript, coding for ADP-glucose pyrophosphorylase, a key gene in the starch biosynthetic pathway is described. This paper confirms t hat kinetics of expression revealed by cDNA-AFLP analysis are comparab le to those found in Northern analysis. Furthermore, this paper report s the isolation and analysis of two tuber-specific transcript-derived fragments TDFs) coding for the lipoxygenase enzyme, which are differen tially induced around the time point of tuber formation. Analysis of t he two lox TDFs demonstrates that it is possible to dissect the expres sion modalities of individual transcripts, not independently detectabl e by Northern analysis. Finally, it is shown that using cDNA-AFLP, rap id and simple verification of band identity may be achieved. The resul ts indicate that cDNA-AFLP is a broadly applicable technology for iden tifying developmentally regulated genes.