Structure of the <i>S. borealis cox1</i> gene introns 1 (A) and 8 (B).

<p>Introns are represented by black horizontal bars; the sizes are drawn to scale. Red arrows show HEG-like ORFs. Green and blue rectangles show, respectively, catalytic GIY-YIG_bI1_like (cd10445) and LAGLIDADG_1 (pfam00961) domains. Nucleotide sequence similarity is indicated by grey areas between introns. Sbor – <i>S. borealis</i>, Bfuc – <i>B. fuckeliana</i>, Pmal – <i>P. malacea</i>, Pans – <i>P. anserina</i>.