Project description:The daily cycle of night and day affects the behaviour and physiology of almost all living things. At the molecular level, many genes show daily changes in expression levels. To determine whether changes in transcript abundance occur in wood forming tissues of Eucalyptus trees we used a cDNA microarray to examine gene expression levels at roughly four hour intervals throughout the day. Experiments were performed using RNA extracted from two biological replicates - GU (Eucalyptus grandis x E. urophylla) and GC (Eucalyptus grandis x camaldulensis) trees. A loop design was used, linking six time points. A dye swap was incorporated to eliminate dye bias.