Composition of transposon-based repeats 45%of the human genome LINEs LINE-1 family ~600,000 autonomous nonautonomous LINE-2 family 370,000 ORF1 ORF2(poD LINE-3 family 44,000→P SINES 6-8 kb Alu family ~1,200,000 MIR ~450,000 100-400bp ∥|R3 85,000 retrovirus-like(LTR transposons) LTR HERV families ~240,000 P gag pol (env) LTR (gag) LTR MaLR 285,000 6-11kb 1.5-3kb DNA transposon fossils MER1(Charlie) ~213,000 transposase MER2 (Tigger 68000 2-3kb others 60,000 80 bp-3 kb ORF open reading frame, gag= viral capsid protein; pol= reverse transcriptase, env=envelope protein, LTR= long terminal repeatComposition of transposon-based repeats (~45% of the human genome) ORF = open reading frame, gag = viral capsid protein; pol = reverse transcriptase, env = envelope protein, LTR= long terminal repeat