YI-type shuttle integrative vector targeting human Alu sequences in YAC libraries derived from somatic cell hybrids. [1] Constructed by inserting a blunt-ended 1.2 kb fragment containing S. cerevisiae HIS3 into the blunted PflMI within the Alu sequence of BLUR8. [1] Linearizing with BamHI removes the plasmid sequences from the Alu ends for targeting integration. [1] Transformation into pools from a YAC library derived from a human-mouse somatic cell hybrid, and selection for His+, resulted in an approximate 50-fold enrichment for Alu-containing YACs. [1] Larger YACs were preferentially selected. Some YACs demonstrated loss of Alu-containing restriction fragments suggesting internal deletions resulting when the vector targeted two Alu sequences in the YAC. [1] Restriction digests of the clone give the following sizes (kb): BamHI–3.0, 1.5; EcoRI–4.5; PstI–4.2 +smaller. (ATCC staff) Medium is 1227 LB plus ampicillin. Hosts: E.coli HB101, Saccharomyces cerevisiae, E.coli, Saccharomyces cerevisiae YPH252, Saccharomyces cerevisiae CGY2516 [ATCC 74013].