Fig. (3) Mapping of the chaetognath ESTs bearing retrotransposon sequences on one of the closer complete retrotransposon genome. For each EST, homologous region between the retrotransposon is in continuous line, whereas, region which does not exhibit homology is in dash line. Concerning the retrotransposons, open reading frames are surrounded by continuous lines, non coding region are symbolized by a continuous line, whereas, long terminal repeats (LTR) or “pseudo-LTR” structure (PLTR) are surrounded by dash lines. For each retrotransposon, the length in base pairs (bp), its name, the name of the species bearing the element and the accession number or the corresponding reference are given. Abbreviations: [µsat] region containing microsatellite repeats, (pA) polyA trail, (gag) group antigen gene, (pol) polymerase gene, (env) envelope gene; and the various domains of the pol gene: (PR) protease, (RT) transcriptase inverse, (RNase H) RNase H, (IN) integrase.