SHORT COMMUNICATION Localization of Short/Branched Chain Acyl-CoA Dehydrogenase (ACADSB) to Human Chromosome 10 KAREN C. ARDErv,*Y’ CARRIE 5. MARS,* KATHERINE Fu,+ AND RIMA ROZEN+ *Ludwig institute for Cancer Research and tDepartment of Medicine, University of California at San Diego, La Jolla, California; and *McGill University-Montreal Children’s Hospital Research Institute, Montreal, Quebec, Canada zyxwvutsrqponmlkjihgfedcba Received October 18, 1994 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONM Shortbranched chain acyl-CoA dehydrogenase, SBCAD (gene symbol ACADSB), is a member of the acyl-CoA dehydrogenase family of genes with activity toward the short/branched chain acyl-CoA derivatives as well as short/straight chain acyl-CoAs. Southern blot analysis of DNA from a panel of human/rodent somatic cell hybrids localized ACADSB to human chromosome 10, and fluorescence in situ hybridization experiments confirmed the chromosomal assignment and refined the subchromosomal localization to lOq25-q26. 0 1996 Academic Press, Inc. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA The acyl-CoA dehydrogenases (ACDs) are a family of mitochondrial enzymes involved in the metabolism of fatty acids or branched chain amino acids through the oxidation of straight chain or branched chain acyl- CoAs. Seven mammalian genes have been described; each gene encodes an enzyme with specific activity re- lated to the chain length and configuration of the sub- strate(s). ACDs are synthesized in a precursor form with a leader peptide sequence that is cleaved upon translocation into the mitochondria (4). Hereditary de- ficiencies of several acyl-CoA dehydrogenases result in potentially lethal metabolic imbalances (2, 8, 10). Mutations in four human ACD genes have been de- scribed in acyl-CoA dehydrogenase-deficient patients (3, 11, 12). The isolation and characterization of a cDNA encod- ing a novel member of the human ACD gene family has recently been reported (9). This new family mem- ber has significant sequence similarity to the other members of the acyl-CoA dehydrogenase family, with the greatest homology (38%) to the short chain acyl- CoA dehydrogenase. Since its greatest activity is to- ward 2-methyl short/branched chain acyl-CoAs, it has been designated short/branched chain acyl-CoA dehy- drogenase (SBCAD; GenBank Accession No. U12778; GDB Nomenclature ACADSB). Here we have determined the chromosomal localiza- tion of ACADSB using Southern blot analysis of a series 1 To whom correspondence should be addressed at the Ludwig In- stitute for Cancer Research, 9500 Gilman Drive, La Jolla, CA 92093- 0660. Telephone: (619) 534-7807. Fax: (619) 534-7750. of human zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJ x hamster somatic hybrid cell lines that seg- regate human chromosomes as described by (1). Briefly, genomic DNA from the cell hybrids was digested with HindIII, separated by agarose gel electrophoresis, transferred to nylon membranes, and hybridized with a radiolabeled SBCAD cDNA probe. The 2.0-kb cDNA clone containing the entire coding sequence and ap- proximately 650 bp of the 3 ’ untranslated region hy- bridized to four Hind111 fragments (9.5, 5.5, 4.3, and 1.4 kb) in human genomic DNA (Fig. 1). Chromosomal localization was determined by scoring the presence or absence of human-specific bands on the autoradiograph of the Southern blot shown in Fig. 1. Only the presence or absence of chromosome 10 was concordant with SBCAD hybridization, while at least three discordan- cies were observed for every other chromosome. These data as well as the human chromosomal content of the somatic cell hybrids are summarized in Table 1. Cross- hybridization to hamster DNA indicates the presence of a homologous gene in this species. The regional localization of the ACADSB gene was determined by fluorescence zyxwvutsrqponmlkjihgfedcbaZYX in situ hybridization (FISH), using a genomic clone obtained by screening an ATCC chromosome lo-specific library (Fu and Ro- zen, unpublished data). Normal human metaphase spreads were hybridized with the 6.0-kb genomic clone labeled with biotin-16-dUTP (Boehringer Mannheim) and biotin-14-dCTP by random priming FIG. 1. Autoradiograph of a Southern hybridization of the SBCAD cDNA clone to Hind111 restriction enzyme digests of genomic DNA from human, hamster, and hybrid cells. The presence or ab- sence of human chromosome 10 was concordant with the presence or absence of human-specific bands. 743 GENOMICS 25, 743-745 (19%) 0888-7543/95 $6.00 Copyright 0 1995 by Academic Press, Inc. All rights of reproduction in any form reserved.