(See figure on facing page.) Characterization of partner LINEs that share 3′ tails with respective V-SINEs. The zebrafish ZfL3 and lungfish LfR1 each belong to a LINE family with an open reading frame (ORF) that encodes a typical RTase (A). The RTase domains are highlighted in black (Xiong and Eickbush 1990; Malik et al. 1999). A comparison between zebrafish ZfL3 LINEs and the DANA SINE (B). The top line shows the consensus sequence of the DANA SINE. Asterisks indicate nucleotides in the consensus sequence of the zebrafish ZfL3 LINE that are identical to those in the consensus sequence of the DANA SINE. Nucleotides are highlighted in black when they predominate at a given position. Among four nucleotides, when two nucleotides are identical and the other two nucleotides differ from them but are identical, they are not highlighted but are indicated by asterisks when either pair is identical to the consensus nucleotide of V-SINEs. Dashes indicate gaps inserted to improve the alignment. The 3′-terminal repeats of the DANA SINE are underlined with bold half-arrowheads and those of ZfL3 LINEs are similarly underlined with dots. The junction between the SINE and LINEs is shown by a vertical line. A comparison between lungfish LfR1 LINEs and the Lun1 SINE (C). The top line shows the consensus sequence of the Lun1 SINE. Asterisks indicate identical nucleotides in the consensus sequences of the lungfish LfR1 LINE and the Lun1 SINE. Nucleotides are highlighted in black when at least two are identical at a given position. Dashes indicate gaps inserted to improve the alignment. The 3′-terminal repeats are underlined with bold half-arrowheads. The junction between the SINE and LINEs is shown by a vertical line.
