loos1 gene structure. (a) Map of the loos1 gene organization. Exons are shown as arrows and introns as lines, drawn to scale. (b) The predicted core of the promoter region containing a TATA box at -25 is distinguished in large letters, as well as the nucleotide indicating the predicted site of transcription initiation (TSS). Untranslated regions, 5' and 3', and a possible polyadenylation signal are shown flanking the coding sequence of loos1. Introns I, II and III are shown in lowercase italic letters, to compare to the coding sequence of loos1.