Branch A D, Berns M W
Chromosoma. 1976 Jun 30;56(1):33-40. doi: 10.1007/BF00293727.
Most cells of the male PTK2 cell line contain one nucleolus, and they are diploid. However, a proportion of cells have more than one nucleolus. Cells with two and three nucleoli were isolated and cloned into viable populations. Greater than 90% of the cells in these clonal populations maintained the abnormal nucleolar number of the originally isolated cell. Karyotype analysis of cells with two and three nucleoli demonstrated that the cells were respectively tetraploid and hexaploid. It was concluded that in PTK2 cells, nucleolarity is a good index of ploidy even if the ploidy level is abnormal. Furthermore, long term monitoring of the tetraploid cells demonstrated virtually no tendency towards reversion to the diploid condition as suggested by other studies in Potorous.
雄性PTK2细胞系的大多数细胞含有一个核仁，并且它们是二倍体。然而，一部分细胞有不止一个核仁。分离出具有两个和三个核仁的细胞并克隆成可存活的群体。这些克隆群体中超过90%的细胞维持了最初分离细胞的异常核仁数。对具有两个和三个核仁的细胞进行核型分析表明，这些细胞分别是四倍体和六倍体。得出的结论是，在PTK2细胞中，即使倍性水平异常，核仁数也是倍性的一个良好指标。此外，对四倍体细胞的长期监测表明，几乎没有如在长鼻袋狸的其他研究中所暗示的向二倍体状态逆转的趋势。
