Excision activity of Mos1, SB, and FP transposons in Ciona. (a) (top part) Excision of Mos1. The left panel shows the polymerase chain reaction result of Mos1 transposon and transposase-injected embryos; the right panel shows the results of Mos1 transposon-injected control embryos. The expected sizes of correct excision events are shown by arrowheads. (bottom part) Footprint sequences of Mos1 observed in Ciona and typical footprint sequences reported previously (typical footprint). (b) Excision of Sleeping Beauty (SB). Note that three to six times more transposon DNA was injected in this experiment, which resulted in the detection of excised bands from every embryo. (c) Excision of Frog Prince (FP). bp, base pairs; M, marker lane.