Ernst T, Jackson C, Barnes D
Department of Biochemistry and Biophysics, Oregon State University, Corvallis 97331-6503.
Cytotechnology. 1991 Mar;5(3):211-22. doi: 10.1007/BF00556291.
Mouse embryo cultures derived in serum-containing medium undergo growth crisis or senescence after fewer than 20 population doublings, followed by the emergence of genetically altered, polyploid 'immortalized' cells capable of growing indefinitely. Serum-free mouse embryo (SFME) cells, derived in medium in which serum is replaced with growth factors and other supplements, do not exhibit growth crisis or gross chromosomal aberrations when cultured for well over 100 population doublings and display other unique properties. We examined culture conditions and physiological factors affecting karyotypic stability in long term cultures of SFME cells derived from several mouse strains. Cloning SFME cells consistently isolated colonies with altered karyotype, even when the clones were derived from parent cultures with no karyotypic alterations. After 140-200 population doublings in vitro, the percentage of SFME cells showing hyperdiploidy or structural chromosomal abnormalities increased, although the modal chromosome number remained diploid. SFME cells transformed with molecularly cloned oncogenes did not show alterations in karyotype beyond that expected from the clonal origins of these cells, indicating that malignant transformation of SFME cells does not result in general karyotypic instability.
在含血清培养基中培养的小鼠胚胎细胞，在少于20次群体倍增后会经历生长危机或衰老，随后会出现基因改变的多倍体“永生化”细胞，这些细胞能够无限生长。无血清小鼠胚胎（SFME）细胞是在将血清替换为生长因子和其他补充剂的培养基中培养得到的，在培养超过100次群体倍增时不会出现生长危机或明显的染色体畸变，并且表现出其他独特特性。我们研究了影响来自几种小鼠品系的SFME细胞长期培养中核型稳定性的培养条件和生理因素。克隆SFME细胞时，即使克隆来源于没有核型改变的亲代培养物，也始终能分离出核型改变的菌落。在体外进行140 - 200次群体倍增后，显示超二倍体或染色体结构异常的SFME细胞百分比增加，尽管众数染色体数仍为二倍体。用分子克隆的癌基因转化的SFME细胞，其核型改变并未超出这些细胞克隆起源所预期的范围，这表明SFME细胞的恶性转化不会导致一般的核型不稳定。
