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The electronic form of this document may be cited in the following style:
Human Genome Program, U.S. Department of Energy, DOE Human Genome Program Contractor-Grantee Workshop IV, 1994.
Abstracts scanned from text submitted for November 1994 DOE Human Genome Program Contractor-Grantee Workshop. Inaccuracies have not been corrected.
COMPARATIVE MAPPING OF A CONSERVED ZINC-FINGER GENE CLUSTER IN MAN AND MOUSE
Mark Shannon[1,3], Michael L. Mucenski, Linda Ashworth, and Lisa Stubbs
Biology Division, Oak Ridge National Laboratory, P.O. Box 2009, Oak Ridge, TN 37831-8080; Human Genome Center, Lawrence Livermore National Laboratory; Corresponding author.
A comprehensive program aimed at man-mouse comparative mapping of human chromosome 19 is being conducted as a collaboration between the Biology Division at the Oak Ridge National Laboratory and the Human Genome Center at the Lawrence Livermore National Laboratory. The broad objectives of these studies are to establish the structural relationships between the genes in regions of man-mouse homology and to use the mouse as a model system for determination of the functions of those resident genes. In this study, we extend comparative mapping to the detailed analysis of a 200-300kb region located near the human XRCC1 gene in 19q13.2, that has been shown to carry a cluster of zinc-finger (ZNF) genes. We report the isolation of a genomic fragment from the region containing DNA that is not related to the ZNF-consensus sequence, but that is present in multiple copies within the gene cluster and conserved in a variety of vertebrate species. Sequence analysis has indicated that the genomic fragment encodes the A domain of the Kruppel associated box (KRAB), which is estimated to be present in one-third of the ZNF genes of the Kruppel (C2H2) type. Interestingly, this conserved human fragment detects a small number of independent loci on Southern blots of mouse genomic DNA, and interspecific backcross (IB) analysis has demonstrated that most or all of these cross-hybridizing sequences are located in the related Xrcc1 region of mouse chromosome 7.
These results suggest that the human KRAB fragment may preferentially recognize genes within the homologous murine KRAB-containing ZNF gene cluster. This suggestion is supported by the fact that the related murine sequences are restricted to single, independent 225 kb fragments in Mlul- or Eagl-digested genomic DNA. These data serve to define a maximum size for the mouse ZNF cluster which is comparable with the estimated length of the human 19q13.2 ZNF gene region. Using the human KRAB sequence as a probe, we have identified mouse cosmids spanning the murine ZNF gene region, as well as cDNA clones that may represent some of the estimated 10-20 independent ZNF genes in this region. Functional characterization of the murine ZNF genes, in conjunction with restriction mapping and sequencing studies of human chromosome 19q13.2 that are currently underway at LLNL, will eventually allow complete structural and functional analysis of this region of man-mouse homology.
This work was supported by USDOE under contract DE-AC05840R21400 with Martin Marietta Energy Systems, Inc., and contract W-7405-ENG-48 with the Lawrence Livermore National Laboratory. M.S. is supported by a DOE Human Genome Distinguished Postdoctoral Fellowship.