Potten C S
Int J Radiat Biol Relat Stud Phys Chem Med. 1986 Feb;49(2):257-78. doi: 10.1080/09553008514552541.
In the replacing tissues of the body, namely the bone marrow, testis, and the surface epithelia with their appendages, cell replacement would appear to be achieved using an hierarchically organized proliferative compartment with relatively few ultimate stem cells producing dividing transit cells which eventually differentiate and mature into the functional cells of the tissue. The cell cycle times of the various constituents of the hierarchy differ, and the stem cells apparently have a longer cell cycle than the transit cells. There may be variations in the cell cycle as cells pass through the transit population in some cases, e.g. in the bone marrow, while in others the cycle time remains fairly constant, e.g. in the testis. The difference in the cell cycle time between stem cells and transit cells is not completely unequivocal, and there is little or no difference in cycle time in the epithelium on the dorsal surface of the tongue while in other cases the experimental evidence for long stem-cell cycles is somewhat imprecise. However, the epithelium in the small intestine and the spermatogonia in the testis have been fairly extensively studied and here the evidence clearly shows a lengthening of the cell cycle as more primitive cells are considered.
在身体的替代组织中，即骨髓、睾丸以及带有附属器的表面上皮组织，细胞替代似乎是通过一个层次结构组织的增殖区室来实现的，其中相对较少的终末干细胞产生分裂的过渡细胞，这些过渡细胞最终分化并成熟为组织的功能细胞。该层次结构的各个组成部分的细胞周期时间不同，干细胞的细胞周期显然比过渡细胞长。在某些情况下，例如在骨髓中，当细胞通过过渡群体时，细胞周期可能会有变化，而在其他情况下，例如在睾丸中，周期时间保持相当恒定。干细胞和过渡细胞之间的细胞周期时间差异并非完全明确，舌背表面上皮的周期时间几乎没有差异，而在其他情况下，关于长干细胞周期的实验证据有些不精确。然而，小肠上皮和睾丸中的精原细胞已经得到了相当广泛的研究，在这里，证据清楚地表明，随着考虑更原始的细胞，细胞周期会延长。
