Moore B B, Tan J, Lim P L, Tucker P W, Yuan D
Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235.
Nucleic Acids Res. 1993 Mar 25;21(6):1481-8. doi: 10.1093/nar/21.6.1481.
Previous experiments have shown that the extent of delta gene transcription during B cell development is regulated primarily at the transcriptional level. We have shown that deletion of a sequence located between the mu and delta coding regions in the Ig heavy chain locus where transcriptional termination has been previously mapped abrogates the termination. Restoration of termination requires reintroduction of this segment as well as sequence elements within the microM poly (A) site which cannot be substituted by the microS poly (A) site. Recognition of the termination site by non-lymphoid cells suggests that initiation of delta transcription in mature B lymphocytes requires the activation of an anti-termination mechanism not yet developed in early B cells.
先前的实验表明，B细胞发育过程中δ基因转录的程度主要在转录水平受到调控。我们已经表明，在Ig重链基因座中μ和δ编码区之间的一个序列被删除后，转录终止就会被废除，而该序列之前已被定位为转录终止位点。恢复终止需要重新引入该片段以及μM聚腺苷酸化位点内的序列元件，这些元件不能被μS聚腺苷酸化位点替代。非淋巴细胞对终止位点的识别表明，成熟B淋巴细胞中δ转录的起始需要激活一种早期B细胞中尚未发育的抗终止机制。
