A FLUORESCENCE IN-SITU HYBRIDIZATION STUDY OF THE REGULATION OF HISTONE MESSENGER-RNA LEVELS DURING THE CELL-CYCLE OF TRYPANOSOMA-BRUCEI

We have analysed the regulation of histone H2A, H2B, H4 and beta-tubul in RNA levels during the cell cycle of asynchronous cultures of Trypan osoma brucei by fluorescence in situ hybridisation. Whereas tubulin mR NA is detectable at high levels during the entire cell cycle, histone mRNA presence peaks during S phase and is not detectable during all ot her stages of the cell cycle within the sensitivity limits of this tec hnique. We show that fluorescence in situ hybridisation can be used to characterise the distribution patterns of cell cycle regulated transc ripts in asynchronous cell culture systems and discuss the possibiliti es and limitations of quantification of hybridisation patterns by mean s of computer-assisted image analysis.