Several short interspersed repetitive elements (SINEs) in distant species may have originated from a common ancestral retrovirus: characterization of a squid SINE and a possible mechanism for generation of tRNA-derived retroposons

Proc Natl Acad Sci U S A. 1993 Jul 1;90(13):6260-4. doi: 10.1073/pnas.90.13.6260.


Using labeled transcripts generated in vitro from squid total genomic DNA as a probe, we isolated and characterized a SINE that is present in the squid genome. The squid SINE appears to be derived from a tRNA(Lys). When the consensus sequences of five different SINEs with a tRNA(Lys)-like structure from distantly related species, including squid, were aligned, we found in the tRNA-unrelated region two sequence motifs that were almost identical among these five SINEs. This observation suggests a common evolutionary origin for these SINEs and/or some function(s) for these motifs. Similar sequences were unexpectedly found to be present in sequences complementary to the U5 regions of several mammalian retroviruses whose primer is a tRNA(Lys). On the basis of these findings, we present a model for the generation of SINEs. We propose that they are derived from a "strong-stop DNA" with a primer tRNA(Lys) that is an intermediate in the reverse transcription of certain retroviruses. Our model suggests that a certain group of SINEs may have been generated by horizontal transmission, although it is not clear whether information was transmitted via a similar retrovirus or via an RNA or DNA of a SINE.

MeSH terms

  • Animals
  • Base Sequence
  • Biological Evolution
  • Decapodiformes / genetics*
  • Genes*
  • Models, Genetic
  • Molecular Sequence Data
  • RNA, Transfer / genetics*
  • Repetitive Sequences, Nucleic Acid*
  • Retroviridae / genetics*
  • Sequence Homology, Nucleic Acid


  • RNA, Transfer

Associated data

  • GENBANK/D14860
  • GENBANK/D14861
  • GENBANK/D14862
  • GENBANK/D14863
  • GENBANK/D14864
  • GENBANK/D14865