CHARACTERIZATION OF A SHORT INTERSPERSED REPEAT (MERMAID) THAT HAS FAMILY MEMBERS ON HUMAN-CHROMOSOME-21 AND ELSEWHERE IN THE HUMAN GENOME

To understand the architecture of the human genome, we need a complete definition of all the repeat sequence families, as these make up the majority of human DNA. We have isolated a small DNA fragment from huma n chromosome 21 and have used sequence analysis of this fragment to un cover a new low copy repeat element ment of approximately 300 bp that we term the Mermaid repeat. This repeat is related to, but is differen t from, the MER12 repeat and is interspersed in the genome. Mermaid fa mily members that we have studied are between 81%-87% identical to our preliminary consensus sequence, Therefore, we have added a new member to the large collection of human repetitive elements, In addition, we have mapped a Mermaid repeat to a telomeric position on the long ann of human chromosome 21, at 21q22.3.