Van Zant G, Chen J J, Scott-Micus K
Department of Cell Biology and Anatomy, Texas Tech University Health Sciences Center, Lubbock 79430.
Blood. 1991 Feb 15;77(4):756-63.
Genetic markers of two general types have been used to assess the number of simultaneously productive stem cells in vivo, retrovirus markers and enzyme or hemoglobin variants. Use of the two techniques has led to different conclusions regarding stem-cell population organization, kinetics, and usage. To better understand this discrepancy, we have combined the two methods by retrovirally marking and transplanting stem cell populations of allophenic mice in which all tissues, including the hematopoietic system, are chimeric. Hematopoietic and lymphoid tissues of engrafted recipients were analyzed by Southern blotting to determine the number and extent of participation of individually marked stem cells. Genotypic chimerism of the same tissues was determined by quantitating electrophoretic variants of glucose phosphate isomerase. This procedure permitted the genotypic identification of individual stem-cell clones. The results demonstrate the participation of few pluripotent stem cells in the repopulation and maintenance of engrafted hematopoietic and lymphoid tissues. Furthermore, stem cells used during the period of early engraftment tended to be of one genotype (DBA/2), whereas stem cells used for long-term maintenance tended to be of the other, coexistent genotype (C57BL/6). We propose that this genotypic specificity reflects functional differences in stem-cell subpopulations and their relative prevalence in different mouse strains suggests a genetic component in the organization and usage of stem cells.
两种常见类型的遗传标记已被用于评估体内同时发挥作用的干细胞数量，即逆转录病毒标记以及酶或血红蛋白变体。这两种技术的使用得出了关于干细胞群体组织、动力学和使用情况的不同结论。为了更好地理解这种差异，我们通过逆转录病毒标记和移植异表型小鼠的干细胞群体，将这两种方法结合起来，在异表型小鼠中，包括造血系统在内的所有组织都是嵌合的。通过Southern印迹法分析移植受体的造血和淋巴组织，以确定单个标记干细胞的参与数量和程度。通过定量磷酸葡萄糖异构酶的电泳变体来确定相同组织的基因型嵌合情况。这个过程允许对单个干细胞克隆进行基因型鉴定。结果表明，很少有多能干细胞参与移植的造血和淋巴组织的重新填充和维持。此外，早期移植期间使用的干细胞往往属于一种基因型（DBA/2），而用于长期维持的干细胞往往属于另一种共存的基因型（C57BL/6）。我们认为，这种基因型特异性反映了干细胞亚群的功能差异，并且它们在不同小鼠品系中的相对流行率表明干细胞的组织和使用存在遗传成分。
