title: Genetic stability of murine pluripotent and somatic hybrid cells may be affected by conditions of their cultivation.
abstract: Using mouse pluripotent teratocarcinoma PCC4azal cells and proliferating spleen lymphocytes we obtained a new type of hybrids, in which marker lymphocyte genes were suppressed, but expression the Oct-4 gene was not effected; the hybrid cells were able to differentiate to cardiomyocytes. In order to specify the environmental factors which may affect the genetic stability and other hybrid properties, we analyzed the total chromosome number and differentiation potencies of hybrids respectively to conditions of their cultivation. Particular attention was paid to the number and transcription activity of chromosomal nucleolus organizing regions (NORs), which harbor the most actively transcribed - ribosomal - genes. The results showed that the hybrids obtained are characterized by a relatively stable chromosome number which diminished less than in 5% during 27 passages. However, a long-term cultivation of hybrid cells in non-selective conditions resulted in preferential elimination of some NO- chromosomes, whereas the number of active NORs per cell was increased due to activation of latent NORs. On the contrary, in selective conditions, i.e. in the presence of hypoxantine, aminopterin and thymidine, the total number of NOR-bearing chromosomes was not changed, but a partial inactivation of remaining NORs was observed. The higher number of active NORs directly correlated with the capability of hybrid cells for differentiation to cardiomyocytes.
authors.affiliation: Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow.
authors.forename: Shramova Elena
authors.initials: SE
authors.lastname: Ivanovna
authors.forename: Larionov Oleg
authors.initials: LO
authors.lastname: Alekseevich
authors.forename: Khodarovich Yurii
authors.initials: KY
authors.lastname: Mikhailovich
authors.forename: Zatsepina Olga
authors.initials: ZO
authors.lastname: Vladimirovna
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D065150:Cellular Reprogramming / Q000187:drug effects / Q000235:genetics; D043171:Chromosomal Instability / Q000187:drug effects / Q000235:genetics*; D033481:Chromosomes, Mammalian / Q000235:genetics; D003470:Culture Media / Q000494:pharmacology; D004275:DNA, Ribosomal / Q000235:genetics; D006822:Hybrid Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006824:Hybridization, Genetic / Q000187:drug effects; D017404:In Situ Hybridization, Fluorescence; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018895:Microsatellite Repeats / Q000235:genetics; D009697:Nucleolus Organizer Region / Q000235:genetics; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012834:Silver / Q000378:metabolism
chemical_list: D003470:Culture Media; D004275:DNA, Ribosomal; D012834:Silver