title: Cell-specific expression of transfected brain identifier repetitive DNAs.
abstract: To define the neural-specific expression of rat repetitive identifier (ID) DNA, we co-transfected an intron B subclone of the rat growth hormone (rGH) gene, containing a tandem array of two type 2 repeats and a single ID monomer, and a plasmid conferring neomycin resistance into human SK-N-MC neuroblastoma, HeLa epidermal carcinoma, 293 kidney and 251 MG glioblastoma cells. Transcript analysis from both individual and pools of G418-resistant cells revealed that rGH intron B repeats were expressed only in SK-N-MC neuroblastoma cells as small, cytoplasmic RNAs of 85, 110, 155 and 180 bases. Primer-extension studies show these repetitive RNAs to contain a common 5' end that maps precisely to the beginning of the ID element and that type 2 transcripts are not stably expressed. However, ID DNA expression from two other transfected plasmids, each containing only the ID core sequence, was not restricted to the SK-N-MC cell line. These data show that the transfected rGH ID sequence is selectively expressed in a neural-specific manner resulting in BC-like RNAs, and furthermore, suggest that flanking DNA may play a role in cell-specific expression of certain repetitive DNA elements.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002460:Cell Line; D004247:DNA / Q000235:genetics*; D005796:Genes; D013006:Growth Hormone / Q000235:genetics*; D006801:Humans; D008970:Molecular Weight; D010957:Plasmids; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D051381:Rats; D012091:Repetitive Sequences, Nucleic Acid; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D012313:RNA; D013006:Growth Hormone; D004247:DNA