CHARACTERIZATION OF A REGION-SPECIFIC LIBRARY OF MICROCLONES IN THE VICINITY OF THE BCG AND SPLOTCH LOCI ON MOUSE CHROMOSOME-1

The proximal portion of mouse chromosome 1 harbors a variety of mutant loci that have yet to be characterized at the molecular level. We hav e constructed a library of genomic DNA fragments from the proximal por tion of mouse chromosome 1 by microdissection and microcloning techniq ues, with the aim of generating genetic markers in close proximity to some of these mutant loci. To facilitate the genetic mapping of 27 mic roclones from this library, we divided a 56-cM segment of chromosome 1 between the Col3a1 and Ren 1,2 genes into eight intervals defined by anchor loci. Restriction fragment length polymorphisms were determined for each of the microclones and their segregation with the anchor loc i was followed in informative animals from a panel of 252 interspecifi c backcross mice (C57BL/6J X Mus spretus) X C57BL/6J. We were able to assign 26 of 27 (96%) randomly selected microclones to each of the def ined chromosome 1 intervals. A total of eight microclones mapped withi n the large interstitial deletion found in the Sp(r) mouse mutant. Two of these clones were found to be tightly linked to the host resistanc e locus Bcg and at least one was found to be linked to the neural tube defect mutant splotch. Other clones mapped to intervals containing se veral other mouse mutants. These novel DNA markers should aid in posit ional cloning strategies presently employed to identify these mutant l oci. These clones should also be useful in the creation of both physic al and YAC contiguous maps of the proximal portion of mouse chromosome 1. (C) 1994 Academic Press, Inc.