The Chinese hamster Alu-equivalent sequence: a conserved highly repetitious, interspersed deoxyribonucleic acid sequence in mammals has a structure suggestive of a transposable element.

A consensus sequence hasbeendetermined foramajor interspersed deoxyribonucleic acid repeat inthegenomeofChinese hamster ovary cells (CHOcells). Thissequence isextensively homologous to(i) thehumanAlusequence (P.L. Deininger etal., J.Mol.Biol., inpress), (ii) themouseBlinterspersed repetitious sequence (Krayev etal., Nucleic AcidsRes.8:1201-1215, 1980), (iii) aninterspersed repetitious sequence fromAfrican greenmonkeydeoxyribonucleic acid (Dhruva etal., Proc. Natl. Acad.Sci. U.S.A. 77:4514-4518, 1980) and(iv) the CHO andmouse4.5Sribonucleic acid(this report; F.HaradaandN.Kato, Nucleic AcidsRes.8:1273-1285, 1980). Because theCHO consensus sequence showssignificant homology tothehumanAlusequence itistermed theCHO Alu-equivalent sequence. Aconserved structure surrounding CHOAlu-equivalent family members canberecognized. Itissimilar tothatsurrounding thehuman AluandthemouseBisequences, andisrepresented asfollows: direct repeat CHO-Alu-A-rich sequence-direct repeat. Acomposite interspersed repetitious sequence hasbeenidentified. Itsstructure isrepresented asfollows: direct repeat-residue 47to107ofCHO-Alu-non-Alu repetitious sequence-A-rich sequence-direct repeat. Because theAluflanking sequences resemble those that flank knowntransposable elements, wethinkitlikely thattheAlusequence dispersed throughout themammalian genomebytransposition.