What is the significance of the thinner continuous rectangles displayed at the begining and end of a known gene in the browser?”
Response: The varying thickness of the Known Genes track denotes the various structural features of a gene, such as the exons, introns, and untranslated regions (UTRs). The thickest parts of the track indicate the coding exon regions within the gene. The slightly thinner portions at the leading and trailing ends of the gene track show the 5′ and 3′ UTRs. Introns are depicted as 1-pixel lines with hatch marks that indicate the direction of transcription. Some aspects of the graphical representation are inevitably lost upon rescaling. For exampe, coding exons are given preference at coarse scales. For single exon genes, there is no place to put the strand orientation wedges and the feature’s detail page must be consulted.
