Fig. 3From: Mitochondrial group I and group II introns in the sponge orders Agelasida and AxinellidaPredicted secondary structure of A. oroides and A. polypoides introns 870 (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 backgroundBack to article page