title: Transfer of a human chromosomal vector from a hamster cell line to a mouse embryonic stem cell line.
abstract: Two transchromosomic mouse embryonic stem (ES) sublines (ESMClox1.5 and ESMClox2.1) containing a human minichromosome (MC) were established from a sample of hybrid colonies isolated in fusion experiments between a normal diploid mouse ES line and a Chinese hamster ovary line carrying the MC. DNA cytometric and chromosome analyses of ESMClox1.5 and ESMClox2.1 indicated a mouse chromosome complement with a heteroploid constitution in a subtetraploid range; the karyotypes showed various degrees of polysomy for different chromosomes. A single copy of the MC was found in the majority of cells in all the isolated hybrid colonies and was stably maintained in the established sublines for more than 100 cell generations either with or without the selective agent. No significant differences from the ES parental cells were observed in growth characteristics of the transchromosomic ES sublines. ESMClox1.5 cells were unable to grow in soft agar; when cultured in hanging drops, they formed embryoid bodies, and when inoculated in nude mice, they produced teratomas. They were able to express the early development markers Oct4 and Nanog, as demonstrated by reverse transcription-polymerase chain reaction assay. All these features are in common with the ES parental line. Further research using the transchromosomic ES sublines described here may allow gene expression studies on transferred human minichromosomes and could shed light on the relationships among ploidy, pluripotency, cell transformation, and tumorigenesis. Disclosure of potential conflicts of interest is found at the end of this article.
authors.affiliation: Dipartimento di Genetica e Microbiologia Adriano Buzzati Traverso Università degli Studi di Pavia, Pavia, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Paulis
authors.forename: Mirella
authors.initials: M
authors.lastname: Bensi
authors.forename: Donata
authors.initials: D
authors.lastname: Orioli
authors.forename: Chiara
authors.initials: C
authors.lastname: Mondello
authors.forename: Giuliano
authors.initials: G
authors.lastname: Mazzini
authors.forename: Maurizio
authors.initials: M
authors.lastname: D'Incalci
authors.forename: Cristiano
authors.initials: C
authors.lastname: Falcioni
authors.forename: Enrico
authors.initials: E
authors.lastname: Radaelli
authors.forename: Eugenio
authors.initials: E
authors.lastname: Erba
authors.forename: Elena
authors.initials: E
authors.lastname: Raimondi
authors.forename: Luigi
authors.initials: L
authors.lastname: De Carli
mesh_terms: D000818:Animals; D016466:CHO Cells; D002459:Cell Fusion; D002460:Cell Line / Q000378:metabolism / Q000637:transplantation; D002469:Cell Separation; D022222:Chromosomes, Artificial, Human / Q000235:genetics*; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus / Q000235:genetics*; D053595:Embryonic Stem Cells / Q000166:cytology*; D005260:Female; D006801:Humans; D006822:Hybrid Cells / Q000166:cytology / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D051379:Mice / Q000235:genetics*; D008819:Mice, Nude; D011003:Ploidies; D013047:Specific Pathogen-Free Organisms; D013724:Teratoma / Q000209:etiology / Q000235:genetics