Schematic diagram of FISH probe sequences of FP-U2-5S which contains the U2 spliceosomal snRNA-like region and partial sequence of 5S rRNA gene sequence (a). FP-X9 is similar to the 5'-untranslated region of uncharacterized gene of a Merulinidae coral (Orbicella faveolata (Ellis et Solander, 1786)) (b). Rectangles in both ends of bars show the primer positions and relative lengths.