Somatic Ceil and Molecular Genetics, Vol. 22, No. 3, 1996, pp. 245-248 Brief Communication Identification of a Locus of Zinc Finger Genes in Human Chromosome 19q13.1-q13.3 Region by Fluorescence in situ Hybridization Ruoxiang Wang, Eva Cukerman, Henry H.Q. Heng, and Choong-Chin Liew The Cardiac Gene Unit, Departments of Clinical Biockemistry and Medicine and the CentreJbr Cardiovascular Research, The Toronto Hospital and the University of Toronto, Toronto, Ontario, Canada. Received I4 March 1996--Final 8 July 1.996 Abstract--A group of zinc-binding eDNA clones from a human fetal heart library was isolated using an oligonucleotide ptvbe m the consensus sequence of the linker region of zinc finger proteins. Genes for novel clones were mapped by fluorescence in situ hybridization. In the process, we identified a previously unrecognized locus fin" two zinc finger-coding genes in human chromosome 19q13.1-q13.3 (ZNF180,ZNF I 81), where genomic rearrangements were shown to be accompanied by various developmental abnormalities, DNA repair deficiencies, and cellular malignancies. The C2H2 zinc finger is a functional motif found in many regulatory proteins (1). Each folding around a zinc ion, these motifs form finger-like structures that exert specific DNA- or RNA-binding activity. Between adjacent fin- gers, a link sequence (H/C Iiak) is highly conserved anaong the C2H2 finger proteins (2), and many zinc finger genes have been isolated based on this feature. Using a similar approach, we have isolated clones encoding zinc fingers from a human fetal heart cDNA library (unpublished data). Briefly, a human fetal heart ZAP Express cDNA library was screened with a degenerate oligonucleotide based on the consensus amino acid sequence of the C2H2 link (2). We isolated a total of 353 positive clones, some of which were used for single-stranded DNA sequencing analysis with the ATaq Sequenase Version 2.0 DNA sequenc- ing kit (United States Biochemicals). Based on on-line homology search against Genbank, clones encoding previously unrecognized zinc fingers were considered novel. These were res- cued into pBK-CMV phagemids by in vivo autoexcision and then were used for the human chromosomal mapping by fluorescence in situ hybridization (FISH). The partial eDNA sequences of two such clones, HHZt68 (ZNF180, Genbank accession number R98367) and HHZI 8 t (ZNF l 81, acces- sion number H54888) are presented in Fig. 1. Supercoiled phagemids of the two clones were used as FISH probes, which were prepared by dATP biotinylation with the BioNick labelling kit (BRL). Methods for preparation of cultured human lymphocyte slides and the FISH protocol have been previously described (3). FISH sig- nals and DAPI banding pattern were recorded. Assignment of the FISH mapping data with chromosomal bands was achieved by superimpo- sition of the FISH signals with DAPI banded chromosomes (4). Detailed position for each of the assignments was determined based on the summary from 10 photos. The two clones mapped to human chromo- some 19q 13.1 -q l 3.3 region: ZNF 181 to 19q 13.1, 245 0740-7750/96/0500-0245509.50/0 9 1996 PlenumPublishingCorporatmn