Fig. 2
From: Mitochondrial group I and group II introns in the sponge orders Agelasida and Axinellida
Predicted secondary structure of A. oroides, A. polypoides and C. verrucosa introns 723 (Group I). The exon and intron bases are indicated in lower-case and upper-case letters, respectively. The conserved sequences (P, Q, R, S) of the intron core and the base-paired regions P1–P10 follow the standard Group I intron scheme [47]. Regions with substantial structural differences among species are indicated with a colored background