The regulated expression of B lineage associated genes during B cell differentiation in bone marrow and fetal liver.
The regulated expression of B lineage associated genes during B cell differentiation in bone marrow and fetal liver.
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DOI：
10.1084/jem.178.3.951
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发表时间：
1993-09-01
影响因子：
15.3
通讯作者：
Hardy, R R
中科院分区：
文献类型：
--
作者：
Li, Y S;Hayakawa, K;Hardy, R R
B谱系相关基因在早期B细胞分化阶段的表达尚未确定。使用细胞表面标记物和多参数流式细胞术，骨髓（BM）细胞可以被分解成六个部分，代表发育的连续阶段;即，前前-Pro-B、早期前-B、晚期前-B/大前-B、小前-B、未成熟B和成熟B细胞。在这里，我们定量的几个B谱系相关基因的水平，在每个这些馏分通过RT-PCR，展示不同的表达模式。我们发现，末端脱氧核苷酸转移酶（TdT），λ 5，和VpreB的表达主要限于前B阶段。Rag-1和Rag-2的表达也受到严格调控，并且主要在Pro-B中通过小的Pre-B阶段发现。Mb-1在整个通路中以高水平存在于Pro-B中。最后，Bcl-2仅在前-Pro-B和成熟B阶段以高水平表达，而在所有中间阶段表达较低。我们还将该表达数据与通过扩增D-JH、VH-DJH和VK-JK评估的IG基因重排的开始分析相关联。最后，我们报告的差异，在B淋巴细胞生成过程中在两个不同的个体发育的时间，在胎儿肝脏和成人骨髓：TdT和前体淋巴细胞调节肌球蛋白样轻链表达在高水平的前B细胞阶段的骨髓，但不存在从相应的分数在胎儿肝脏。相反，λ 5、VpreB、Rag-1和Rag-2的表达水平相当。
The expression of B lineage associated genes during early B cell differentiation stages is not firmly established. Using cell surface markers and multiparameter flow cytometry, bone marrow (BM) cells can be resolved into six fractions, representing sequential stages of development; i.e., pre-Pro-B, early Pro-B, late Pro-B/large Pre-B, small Pre-B, immature B, and mature B cells. Here we quantitate the levels of several B lineage associated genes in each of these fractions by RT-PCR, demonstrating different patterns of expression. We find that expression of terminal deoxynucleotidyl transferase (TdT), lambda 5, and VpreB is predominantly restricted to the Pro-B stages. Rag-1 and Rag-2 expression is also tightly regulated, and is found largely in the Pro-B through small Pre-B stages. Mb-1 is present from Pro-B throughout the pathway at high levels. Finally, Bcl-2 is expressed at high levels only at the pre-Pro-B and mature B stages, whereas it is low during all the intermediate stages. We also correlate this expression data with an analysis of the onset of Ig gene rearrangement as assessed by amplifying D-JH, VH-DJH, and VK-JK. Finally, we report differences in gene expression during B lymphopoiesis at two distinct ontogenic timings, in fetal liver and adult BM: both TdT and the precursor lymphocyte regulated myosin-like light chain are expressed at high levels in the Pro-B cell stage in bone marrow, but are absent from the corresponding fraction in fetal liver. In contrast, lambda 5, VpreB, Rag-1, and Rag-2 are expressed at comparable levels.