BRIEF M APPING REPORTS SEL-1L Maps to Human Chromosome 14, near the Insulin-Dependent Diabetes Mellitus Locus 11 Dorit B. Donoviel* ,1 and Alan Bernstein* , † * Program in Molecular Biology and Cancer, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G-1X5, Canada; and †Department of Molecular and Medical Genetics, University of Toronto, Toronto, Ontario M5S-1A8, Canada Received May 26, 1998; accepted August 13, 1998 Functional gene description: The Notch family of re- ceptors is involved in cell fate decisions in a variety of tissues in multiple organisms. Genetic alterations in the Notch receptors or their ligands have been associated with multiple human disorders as diverse as cancer, stroke, dementia (the CADASIL syndrome), and the Allagile syndrome, which includes multiple developmental abnormalities (reviewed in 6, 8). Given the di- verse role of the Notch pathway in human disease, we were interested in determining whether a human homologue of a recently identified negative regulator of the Notch pathway mapped near any known disease loci. This negative regulator was originally cloned in a suppressor screen in Caenorhabditis elegans and called sel-1 (5). The full-length mouse cDNA for Sel-1l shows 66% similarity to sel-1 at the amino acid level. The expression of Sel-1l and SEL-1L is highest in adult pancreas in mice and humans, respectively, and in the developing murine pancreas. Pancreatic expression is observed in both acini and -islet cells (3). Others have also observed transcripts for SEL-1L in pancreatic adenocarcinomas that are thought to derive from pancreatic ductal cells (1). Name of clone: A human SEL-1L genomic clone was used for the FISH analysis. Primers derived from human EST T95374 (5'-TTTAGCTTCTCAGGGAGGCC, 5'-GCAGA- CTTTCCTGCTGGGCA), which is 52% identical to sel-1 at the amino acid level, were used for the RH mapping. DNA source and its description: Normal human lym- phocyte metaphase DNA was used for the FISH analysis. The Stanford Human Genome Center (SHGC) medium-reso- lution radiation hybrid (RH) map (Research Genetics) was used for the RH mapping of SEL-1L. Method used to validate gene identity: The insert from a human EST (T95374) was used to isolate three genomic clones from a human leukocyte genomic library (Clontech, HL1111j). These were then partially sequenced to confirm their identity by comparison to the mouse cDNA sequence (3), and one was biotinylated and used as a probe in FISH. Methods of mapping: Among 100 mitotic figures, 97 showed signals on one pair of chromosomes. No additional loci were detected. Superimposing FISH signals with DAPI-stained banded chromosome signals derived from the results of 10 photos yielded a unique physical map location (see below). The PCR conditions used with the SHGC medium-resolution RH panel were as recommended by the SHGC. Products were run on a 3% NuSieve agarose gel. Of 83 samples, 13 repeatedly showed the expected bands. The results were submitted to the SHGC (www.shgc.stanford.edu/rhserver2/rhserver_form.html). Results: Both the FISH and the RH mapping indicated that SEL-1L maps to chromosome XIV. The physical map position is in the general area of 14q24.3– q31 (Fig. 1). This localization is consistent with a recent report mapping a partial human cDNA to 14q31 (1). We obtained a higher resolution map position by the RH analysis. SEL-1L was linked to D14S287 with a lod score of 5.3 within a distance of 44.4 cR units, which corresponds to about 1.2 Mb (not shown). D14S287 has been mapped on the SHGC map in the bin just proximal to D14s67 (http://www-shgc.stanford.edu/ Mapping/rh/search.html), which has been linked to the insu- lin-dependent diabetes mellitus (IDDM) locus 11 (4). Additional comments: IDDM is an autoimmune dis- ease that culminates in immune system destruction of pan- creatic -islet cells (2). It has been suggested that IDDM is caused either by the presentation of an aberrant protein on -islet cell surfaces, which marks these cells for destruction by infiltrating lymphocytes, or by the misrecognition of nor- mal islet antigens by abnormal T-cells. This mapping report suggests thatSEL-1L is a candidate for IDDM11. Further support for this hypothesis derives from the observation that SEL-1L protein is highly expressed in an insulin-secreting -islet cell line (3). Furthermore, the putative role of its We thank Dr. Henry Heng from SeeDNA Inc. (Toronto) for human FISH analysis. D.B.D. was a Human Frontiers Science Program Organization Long-term Fellowship recipient. This work was sup- ported by grants from the MRC and NCIC (including funds from the Terry Fox Run) to A.B. 1 To whom correspondence should be addressed. Telephone: (416) 586-8272. Fax: (416) 586-8857. E-mail: donoviel@mshri.on.ca. FIG. 1. Genomic localization of SEL-1L to chromosome 14q24.3– q31 by FISH. (A) Fluorescence staining shows hybridization with a genomic SEL-1L probe to human metaphase chromosomes (white arrows). (B) DAPI-stained chromosomes show that the signal in A corresponds to the long arm of chromosome 14. (C) A Giemsa-band diagram of human chromosome 14 showing the clustering of the fluorescence signal in A to an interval between 14q24.3 and q31. All articles available online at http://www.idealibrary.com on Genomics 56, 232–233 (1999) Article ID geno.1998.5534 232 0888-7543/99 $30.00 Copyright © 1999 by Academic Press All rights of reproduction in any form reserved.