Homology between human and simian repeated DNA.

Abstract

A RELATIVELY small proportion of the total DNA of eukaryotic cells has been considered to be transcribed and translated; the rest of the genome may be variously categorised into several subsets such as spacer and repeated DNAs. Such nontranslated sequences presumably have a role in the modulation of transcription and in the organisation of chromosomes. Some satellite DNAs may be extremely simple in sequence1, even in human DNA2. Other repeated DNAs showing greater sequence complexity have been considered to form a separate subset of repeated DNAs2,3. Very recently, the exact base sequence of such complex repeats has been determined in a few organisms4,5. The conservation of such sequences between related species, and even more extensively in the evolutionary tree, is not known. We report here data which indicate the base order of a subset of human repeated DNA which is fairly complex in sequence. We have shown that such human DNA repeats are quite well conserved both in nucleotide sequence order and in nominal repeat length between human and lower primates.