Chaa,.s ia Tins-host ,oao.. rolatioaship ia tyO subliAes of the SUle Burkitt's ly.' ••••.

The Burkitt lymphoma derived Namalwa ceUline is the best studied case of EBV relationship with the human genome. The segments corresponding to tbose adjacent to the inserted viral genome have been cloned from non-infected human cell DNA (1). We bave subc10ned various parts of one of these segments One subclone was used to probe a genomic library from an in vitro EBV immortalized cell line. tbe question being whether hybrid viral­ human clones would be picked up by this probe. In control experiments we tested the same clone on Namalwa DNA where. according to published data and to our confirming sequence and restriction map. it was expected to be linked to tbe rigbt part of the virus. The result did not show linkage as the Namalwa cell line tested in our laboratory and tbe one used by Kieff bad diversified since they separated from the common ancestor. The common origin of the two sub-lines is indisputable on several grounds including our cytogenetic studies. Thus it appears that we are witnessing some genome rearrangements close to the virus insertion point.