Fig. 5.

(A) The exact position of the insert and a typical Osr4 LTR retrotransposon. LTR (Long terminal repeat) with TG at the 5′ extremity and CA at the 3′ extremity; TSR (target site repeat) is a 5bp short direct repeat string flanking the 5′ and 3′ extremities of an element; PBS, a sequence complemented to the 3′ tail of some tRNA; PPT (polypurine tract) is a short rich purine segment. Protein domains: The gag gene encodes proteins involved in maturation, packaging of retrotransposon RNA and proteins into a form suitable for integration into the genome. Int, integrase; RT, reverse transcriptase; RH, RNase H. (B) The Neighbor-joining tree of 65 LTR-retrotransposon homologs with their DNA sequences. The scale bar indicates the simple matching distance. *Indicate the retrotransposon with a complete CDS. **Indicate the possible functional retrotransposons. (C) The expression of the retrotransposon was detected with RT-PCR. Three different pairs of primers were used for retrotransposon. (D) The Neighbor-joining tree of LTR-retrotransposons in different species with their coding region sequences. *Indicates retrotransposons with a complete CDS.