Brown I R, Danielson P, Rush S, Godbout M, Sutcliffe J G
Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, California 92037.
J Neurosci Res. 1987;18(2):267-73. doi: 10.1002/jnr.490180202.
A genetic element called the identifier (ID) sequence, highly repeated in the rat genome, has previously been reported to be located in the introns of some genes transcribed in the adult rat brain by RNA polymerase II (Pol II). We show that nuclear RNA isolated from neurons of cerebral hemispheres (cortex) of 14-day old rats is enriched more than 10-fold in ID sequences compared to nuclear RNA from liver, kidney, cerebellum, or cortical glia. The developmental onset of the difference is during the first 2 weeks after birth. Mouse cortical neuronal nuclear RNA is similarly enriched in an element related but not identical to the rat ID element, and the enrichment also has postnatal onset. The enriched appearance of ID sequences in transcripts whose expression is increased postnatally in cortical neurons correlates developmentally and spatially with the transcription of ID elements by RNA polymerase III (Pol III) and with a change in chromatin structure.
一种名为标识符（ID）序列的遗传元件在大鼠基因组中高度重复，此前有报道称其位于成年大鼠大脑中由RNA聚合酶II（Pol II）转录的一些基因的内含子中。我们发现，与来自肝脏、肾脏、小脑或皮质神经胶质的核RNA相比，从14日龄大鼠大脑半球（皮质）神经元分离的核RNA中ID序列的富集程度超过10倍。这种差异在出生后的前两周开始显现。小鼠皮质神经元核RNA中同样富集了一种与大鼠ID元件相关但不完全相同的元件，且这种富集也在出生后开始。ID序列在皮质神经元出生后表达增加的转录本中的富集外观在发育和空间上与RNA聚合酶III（Pol III）对ID元件的转录以及染色质结构的变化相关。
