CONSTRUCTION AND CHARACTERIZATION OF A GRIDDED CHICKEN COSMID LIBRARYWITH 4-FOLD GENOMIC COVERAGE

Gridded genomic libraries are crucial for the positional candidate gen e approach. For this purpose we constructed a gridded genomic library from a female chicken using the vector sCos 1. About 110 000 cosmid cl ones were grown and replicated in 384-well plates. An average insert s ize of 39 kb was calculated from the analysis of 68 randomly selected clones. No chimerism could be observed from 31 in situ hybridisations. One replica of the library (number 125) has been transferred to the R esource Centre/Primary Database (RZPD) of the German Human Genome Proj ect (DHGP). The whole library was gridded onto four nylon filters at h igh density for efficient identification of cosmid clones by colony hy bridisation. Twenty-two probes were used for screening the library and each of them gave at least one positive signal. This result is in goo d agreement with a four-fold coverage of the genome as estimated from the insert length and number of recombinant clones. This library provi des a powerful tool for rapid physical mapping and complex analysis of the chicken genome.