ISOLATION FROM HUMAN BRAIN OF 6 PREVIOUSLY UNREPORTED CDNAS RELATED TO THE REVERSE-TRANSCRIPTASE OF HUMAN ENDOGENOUS RETROVIRUSES

cDNAs prepared from total RNA extracted from plaques of multiple scler osis were amplified by the polymerase chain reaction. The 11-bp degene rate primers used were derived from conserved sequences of reverse tra nscriptase. Amplified cDNAs were fractionated according to size by ele ctrophoresis in polyacrylamide gels under denaturing conditions, cDNAs of the proper size were cloned, grouped according to the sequence of their insert by differential hybridization, and sequenced. Six cDNAs w ere isolated and found to belong to new members of two groups of human endogenous retroviruses: the group related to ERV9 and that related t o HERVK10 and HUMMTV. These sequences were expressed in all human orga ns tested, including normal white matter of brain. The approach descri bed in this article is a powerful tool with which to isolate new membe rs of the reverse transcriptase gene family.