Comparison of the gene organizations and intron/exon sizes between P. sinensis IL-1β and known IL-1β genes. The coding regions are represented by filled boxes and the last four exons coding for the region of β-trefoil are filled in grey. The UTRs are depicted with an open box. Introns are shown as a black line with the intron phase above them. The accession numbers of the IL-1β sequences are as follows: AJ314758 (African clawed frog IL-1β), ENSGALT00000000738 (chicken IL-1β), ENST00000263341 (human IL-1β), ENSMUST00000028881 (mouse IL-1β), AJ278242 (trout IL-1β1), AJ311925 (seabass IL-1β), AM18168 (trout IL-1β3).