Degrees of lineage-specific transcription in the LINE superfamily. The phylogenetic tree was generated from a multiple alignment of conceptually translated sequences by using neighbor-joining methods and rooted with human L1. Bootstrap values were calculated from 1,000 replicates. Sample numbers are identical to those in Table 2. Shades of gray indicate the magnitude of transcription signals, which are based on microarray hybridization signals without units. Names of previously reported members are shown. *Previously reported members with transcription or transposition. † Previously reported inactivate members. LINE, long interspersed element.