Diabetes, Vol 46, Issue 3 386-392, Copyright © 1997 by American Diabetes Association
Mapping novel pancreatic islet genes to human chromosomes
J Ferrer, J Wasson, KD Schoor, M Mueckler, H Donis-Keller and MA Permutt
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA. ferrer.jorge@mgh.harvard.edu
A strategy was developed to generate expressed sequence tags (ESTs) from
human pancreatic islet gene products using differential display of mRNA.
Screening of over 2,000 cDNA amplification products identified 42 cDNAs
that were preferentially expressed in pancreatic islets relative to
exocrine tissue. Public database analysis showed that 29 (69%) corresponded
to novel genes, in contrast with only 66 of 250 (26.4%) cDNA clones
randomly selected from a human islet library. Reverse
transcription-polymerase chain reaction (RT-PCR) and/or Northern analysis
of RNA from multiple tissues confirmed that expression was enhanced in
human islet cell RNA for 11 of 15 tested cDNAs. Sequence-tagged sites
developed from 19 islet cDNAs were used to map these genes to human
chromosomes using a combination of monochromosomal somatic-cell hybrids,
genome-wide radiation hybrids, and mega-yeast artificial chromosome
analysis. These results indicate that this PCR-based cDNA selection
strategy yields information on a distinct subset of pancreatic islet
transcribed sequences, which complements ongoing human EST identification
efforts based on random cDNA selection. These mapped ESTs may be used to
assist in the positional cloning of diabetes susceptibility genes.