from the subtelomeric region, consistent with the origin of the half-YAC Mtel15 (5), from which the sequence informa- tion was originally obtained. Sharing of sequences between telomeres has been documented previously (see above). It has also been found recently that the subtelomeric regions of a number of human chromosomes contain members of the ol- factory receptor gene family (10); it is possible that the zinc finger motifs we found in the Mtel15 clone are indicative of a similarly located gene family in mouse. There is known to be paralogy between the telomeres of mouse Chrs 9 and 13 and the pseudoautosomal region (3, 6), but to our knowledge this is the first evidence of a relationship between Chrs 17 and 19. This microsatellite also provides a useful STS marker for the mapping of the ends of Chrs 17 and 19 and so will contribute to the closure of the genetic map. ACKNOWLEDGMENTS We are very grateful to Lucy Rowe and Mary Barter of The Jack- son Laboratory for their assistance with the mapping of these mark- ers. D.K. is a fellow of the Lister Institute of Preventive Medicine. REFERENCES 1. Ceci, J. D., Matsuda, Y., Grubber, J. M., Jenkins, N. A., Cope- land, N. G., and Chapman, V. M. (1994). Interspecific back- crosses provide an important new tool for centromere mapping of mouse chromosomes. Genomics 19: 515–524. 2. Eicher, E. M., and Shown, E. P. (1993). Molecular markers that define the distal ends of mouse autosomes 4, 13, 19 and the sex chromosomes. Mamm. Genome 4: 226 –229. 3. Harbers, K., Francke, U., Soriano, P., Jaenisch, R., and Muller, U. (1990). Structure and chromosomal mapping of a highly polymorphic repetitive DNA sequence from the pseudoautoso- mal region of the mouse sex chromosomes. Cytogenet. Cell Genet. 53: 129 –133. 4. Kipling, D., and Cooke, H. J. (1990). Hypervariable ultra-long telomeres in mice. Nature 347: 400 – 402. 5. Kipling, D., Wilson, H. E., Thomson, E. J., and Cooke, H. J. (1995). YAC cloning Mus musculus telomeric DNA: physical, genetic, in situ and STS markers for the distal telomere of chromosome 10. Hum. Mol. Genet. 4: 1007–1014. 6. Kipling, D., Wilson, H. E., Thomson, E. J., Lee, M., Perry, J., Palmer, S., Ashworth, A., and Cooke, H. J. (1996). Structural variation of the pseudoautosomal region between and within inbred mouse strains. Proc Natl Acad Sci (U S A) 93: 171–175. 7. Manly, K. F. (1993). A Macintosh program for storage and analysis of experimental genetic mapping data. Mamm. Ge- nome 4: 303–313. 8. Rowe, L. B., Nadeau, J. H., Turner, R., Frankel, W. N., Letts, V. A., Eppig, J. T., Ko, M. S. H., Thurston, S. J., and Birken- meier, E. H. (1994). Maps from two interspecific backcross DNA panels available as a community genetic mapping resource. Mamm. Genome 5: 253–274. 9. Starling, J. A., Maule, J., Hastie, N. D., and Allshire, R. C. (1990). Extensive telomere repeat arrays in mouse are hyper- variable. Nucleic Acids Res. 18: 6881– 6888. 10. Trask, B. J. et al (1998). Members of the olfactory receptor gene family are contained in large blocks of DNA duplicated poly- morphically near the ends of human chromosomes. Hum. Mol. Genet. 7: 13–26. Isolation of the Human Beaded- Filament Structural Protein 1 Gene (BFSP1) and Assignment to Chromosome 20p11.23–p12.1 Nanna D. Rendtorff,* ClausHansen,* Asli Silahtaroglu,* , † Karen F. Henriksen,* and NielsTommerup* ,1 * Department of Medical Genetics, Institute of Medical Biochemistry and Genetics, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark; and †Department of Genetics, Division of Biomedical Sciences, Cerrahpasa Medical Faculty, University of Istanbul, Istanbul, Turkey Received March 9, 1998; accepted July 17, 1998 The gene encoding the lens-specific beaded filament structural protein 1 (BFSP1), also referred to as filensin, is a member of the vertebrate intermediate filament Sequence data of the cDNA and genomic sequences of BFSP1 from this article have been deposited with the EMBL/GenBank Data Libraries under Accession Nos. Y16717 (cDNA), Y16718, Y16719, Y16720, Y16721, Y16722, and Y16723 (exon–intron sequences). 1 To whom correspondence should be addressed. Telephone: (+45) 35327826. Fax: (+45) 35327845. E-mail: tommerup@imbg.ku.dk. FIG. 1. Map positions of D17Abb2 and D19Abb1 relative to other markers in The Jackson Laboratory BSB and BSS Interspecific Backcrosses. Not all markers are shown. The raw typing data for all the markers are available on the WWW at http://www.jax.org/ resources/documents/cmdata. Distances between markers are given to the left of each chromosome as centimorgans  standard error. 114 BRIEF REPORTS GENOMICS 53, 114 –116 (1998) ARTICLE NO. GE985478 0888-7543/98 $25.00 Copyright © 1998 by Academic Press All rights of reproduction in any form reserved.