Exon-intron organizations as well as intron positions of five PsGEFs from different species. (A) Exon-intron organizations of DmPsGEF, TcPsGEF, PhcPsGEF, AmPsGEF, and LgPsGEF. The exon and intron are represented by rectangle and straight line, respectively. Exon 1 is on the left. The numbers above exons and below introns indicate their sizes, and thus their scales are different among five PsGEFs. The exon sequences encoding the C2, PDZ, and RhoGEF domains are highlighted by red, green, and blue, respectively. The initiation codon is present in the exon 1 except DmPsGEF in which it is located in the exon 2. (B to D) Intron positions within the C2 (B), PDZ (C), and RhoGEF (D) domain-coding regions of DmPsGEF, TcPsGEF, PhcPsGEF, AmPsGEF, and LgPsGEF are indicated by digits corresponding to the phase of the intron relative to the surrounding codons (phase 0, 1, and 2 introns fall before the first, second, and third bases of a codon, respectively). Asterisk indicates the absence of intron. Some intron positions are conserved at the exact homologous positions and phases between five PsGEFs.