Transcriptional analysis of genes on human chromosome 21
- Univ. of Michigan, Ann Arbor, MI (United States); and others
The polymerase chain reaction (PCR) was used to screen embryonic, fetal and adult human cDNA libraries for transcription on chromosome 21q22.1{yields}21q22.3. 73 pairs of oligonucleotide primers on chromosome 21 were applied to analyze 41 different cDNA libraries. Only phage eluate (and therefore no DNA isolation) was required for this sensitive screening. This technique was first used to demonstrate that huntingtin is expressed ubiquitiously throughout human life. 60 of the primers were positive with at least one library screening, indicating that the majority of primers derived from transcribed sequences. We examined embryonic (which we synthesized), fetal and adult human cDNA libraries. Even with our most complex human fetal brain library, we detected only ca. 50% of transcribed sequences, underscoring the need to screen multiple human cDNA libraries to determine if transcription occurred. Since only 2/73 clones were present in only one cDNA library, the vast majority of transcribed sequences are present in more than one tissue. Because this study involves random genes rather than genes selected because of their import, this demonstrates that only few anonymous genes are transcribed in a single tissue type. Expression of genes in different cDNA libraries aids in comparison between genotype and phenotype. Using combinations of gene-specific and vector-specific primers, we went on to develop a PCR-based technology that retrieves the largest sequences present in a cDNA library. This technology was used to isolate large genes on chromosome 21 that can be used in expression studies to examine the Down syndrome phenotype.
- OSTI ID:
- 134392
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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