Bruner J M, Bursztajn S
Dev Biol. 1986 May;115(1):35-43. doi: 10.1016/0012-1606(86)90225-3.
Clustered and diffuse acetylcholine receptors are present in cultured myotubes. These clustered AChRs represent regions of myotube membrane containing high receptor density. We have studied the distribution of the AChR clusters and nuclei to determine whether there is an association in the distribution of nuclei beneath AChR clusters. AChR clusters were visualized with alpha-bungarotoxin conjugated to tetramethylrhodamine (alpha BTX-TMR) and the nuclei were stained with bisbenzimide which binds specifically to DNA. This double label procedure, and the computerized analysis of the data allowed us to determine the distribution of nuclei and AChR clusters in the same myotube. During early stages of myotube development the nuclei formed aggregates which were comprised of 4 to 10 nuclei in close apposition to one another. This association of AChR clusters with nuclear aggregates was greatest at Day 4 after plating. As the number of nuclear aggregates associated with clusters decreased the number of nuclei in the aggregates also decreased and the AChR clusters decreased in size as well as number. At all time points examined, the concentration of myotube nuclei in the cells was 3 to 12 times higher beneath areas of AChR clusters than away from clusters. Our computerized analysis shows that there is an association of the AChR clusters with the nuclear region during myotube development.
在培养的肌管中存在成簇和分散的乙酰胆碱受体。这些成簇的乙酰胆碱受体代表了肌管膜中受体密度高的区域。我们研究了乙酰胆碱受体簇和细胞核的分布，以确定乙酰胆碱受体簇下方的细胞核分布是否存在关联。用与四甲基罗丹明偶联的α-银环蛇毒素（αBTX-TMR）使乙酰胆碱受体簇可视化，并用特异性结合DNA的双苯甲酰亚胺对细胞核进行染色。这种双重标记程序以及对数据的计算机分析使我们能够确定同一肌管中细胞核和乙酰胆碱受体簇的分布。在肌管发育的早期阶段，细胞核形成聚集体，由4至10个彼此紧密相邻的细胞核组成。接种后第4天，乙酰胆碱受体簇与核聚集体的这种关联最为明显。随着与簇相关的核聚集体数量减少，聚集体中的细胞核数量也减少，并且乙酰胆碱受体簇的大小和数量也减少。在所有检查的时间点，乙酰胆碱受体簇区域下方细胞中肌管细胞核的浓度比远离簇的区域高3至12倍。我们的计算机分析表明，在肌管发育过程中，乙酰胆碱受体簇与核区域存在关联。
