Figure 4.

PRP8 polymorphic intervening sequences in Bathycoccus. (a) Schematic of Bathycoccus intervening and insert-less sequence types. (b) Geographic locations of polymorphic Bathycoccus PRP8 sequences. (c) Phylogenetic relationships among PRP8 coding sequences (nucleotides) that flank intein insertion site d of wild Bathycoccus. Phylogenetic grouping is driven by variations at the third-codon position and this tree should not be used for evolutionary distances as these positions may be saturated. Node support ⩾75% is shown (black dots).