STUDY OF 2 COSMID LIBRARIES SPECIFIC FOR HUMAN-CHROMOSOME-13

We characterized two cosmid libraries constructed from flow-sorted chr omosome 13 at the Imperial Cancer Research Fund (ICRF), UK (13 000 clo nes) and Los Alamos National Laboratory (LANL), USA (17 000 clones). A fter storage for two years; clones showed high viability (95%) and str uctural stability. EcoR I and Hind III restriction patterns were studi ed in more than 500 ICRF and 200 LANL cosmids. The average size of ins erts was shown to be 35-37 kb in both the libraries. Most cosmids (83% and 93% of ICRF and LANL libraries, respectively) exceed the lower si ze limit of DNA fragments that can be packaged and represent a good so urce for physical mapping of chromosome 13. Total length of inserts is four and five genome equivalents in the ICRF and LANL libraries, resp ectively. ICRF cosmids showed hybridization to 22 of 24 unique probes tested, which corresponds to a 90% probability of having any DNA fragm ent represented in the library. More than 1 Mb of chromosome 13 is ove rlapped by 90 cosmids of 22 groups revealed. A chromosomal region of m ore than 150 kb, containing the ATP1AL1 gene for alpha-1 peptide of Na +,K+-ATPase, is covered by 12 cosmids forming a contig. The results of restriction and hybridization analyses are stored in a CLONE database . These data and all the cosmids described are publicly available.