COSMID CLONING AND RESTRICTION-ENDONUCLEASE MAPPING OF THE HERPESVIRUS OF TURKEYS (HVT) GENOME

The genomic libraries of the herpesvirus of turkeys (HVT) presented to date do not include the entire genome. To construct a complete genomi c library, HVT DNA was partially digested with Sau3A and inserted into the double cos site vector pcos2EMBL. The PstI maps derived from the partial Sau3A library demonstrate that the left region of the genome c ompared to the right area is overrepresented. Similar to the libraries of the HVT genome established earlier, a defined portion of the middl e genomic region, however, is not contained in the partial Sau3A libra ry. Cloning of HVT DNA in pcos2EMBL, employing BamHI for the partial d igestion step, enabled to find the recombinant cosmid cBL267 which car ries the BamHI-C and -D fragment as DNA insertion. As shown by Souther n blot hybridization, the BamHI-C fragment ranges in a size to close t he gap in the partial Sau3A library and thus guarantees the completene ss of the genomic library of HVT which consists of seven overlapping c osmid clones (cBL1, cBL328, cBL11, cBL267, cBL27, cBL33, and cBL34).