All vertebrate and invertebrate sequences present in the GenBank database have been aligned according to their mRNA start sites. For some cases the regions between positions -110 and +110 are presented. Previously, two general transcription initiation signals have been noted, the universal TATA box at position -30 and the CAAT box at -75. Our analysis indicates the presence of other signals, at least as significant as the CAAT. Inspection of the aligned sequences reveals the high concentration of G+C near mRNA initiation sites in non-mammalian vertebrates and in mammalians.