Inversion region for hypertension and brachydactyly on chromosome 12p features multiple splicing and noncoding RNA.
Autosomal-dominant hypertension and brachydactyly (Online Mendelian Inheritance in Man 112410) is a prototype-translational research project. We used interphase fluorescent in situ hybridization and discovered complex rearrangements on chromosome 12p in 5 families but elucidated a common inverted region in the linkage interval. The inversion contains no known gene. However, we found 5 expressed sequence tags in databases. We used 5'- and 3'-Rapid Amplification of cDNA Ends PCR for elongation of the transcripts in phenotype-relevant tissue (fetal aorta, fetal brain, and fetal cartilage). We detected tissue-specific multiple splicing with different exon usage of 32 exons in the gene-related structure. These different transcripts lack both open reading frames and Kozak sequences. In vitro transcription/translation experiments did not identify any peptide-related molecules. We then performed quantitative RT-PCR to test for differential expression of the various spliced transcripts in the total fibroblast RNA of affected and nonaffected Turkish family members. Skin fibroblasts of affected individuals have a significantly increased proliferation rate compared with nonaffected individuals. Ten of 12 spliced exon combinations representing all of the spliced variants do not show a significantly different RNA expression rate. However, 2 RT-PCR products are exclusively expressed in nonaffected individuals. Both reverse transcription amplicons share 1 exon. This result is surprising because of the autosomal-dominant mode of inheritance of the trait. RNA secondary prediction of this single exon results in a stable stem-loop structure known to be essential for microRNA processing. We are pursuing the possibility of microRNA expression in affected patients that leads to complete down regulation of a spliced transcript.
Bähring
Sylvia
S
Medical Faculty of the Charité, Experimental and Clinical Research Center, Max-Delbrück Center for Molecular Medicine, and HELIOS Klinikum Berlin-Buch, Berlin, Germany.
Kann
Martin
M
Neuenfeld
Yvette
Y
Gong
Maolian
M
Chitayat
David
D
Toka
Hakan R
HR
Toka
Okan
O
Plessis
Ghislaine
G
Maass
Philipp
P
Rauch
Anita
A
Aydin
Atakan
A
Luft
Friedrich C
FC
D017398:Alternative Splicing; D002455:Cell Division; D007446:Chromosome Inversion; D002874:Chromosome Mapping; D020223:Chromosome Painting; D002881:Chromosomes, Human, Pair 12; D005091:Exons; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression; D005799:Genes, Dominant; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000235:genetics*; D007399:Interphase; D017880:Limb Deformities, Congenital / Q000150:complications / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D035683:MicroRNAs / Q000378:metabolism; D022661:RNA, Untranslated; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000473:pathology
D035683:MicroRNAs; D022661:RNA, Untranslated