[galaxy-user] Only first 5000 reads are displayed in this tile

Hi During the visualization of my mRNAseq data, some area have red line indicating that only the first 5000 reads are displayed. Within this region, some area have many reads. Some area, where exons exist, I don't see any reads. How do I interpret the data? If there are no reads shown in the visualization, although there is a read line saying only the first 5000 reads are displayed, does the absence of reads corresponding to a particular exon means it is not expressed? Thanks, Jeremy