title: A high frequency of mtDNA polymorphisms in HeLa cell sublines.
abstract: The complete mtDNA sequences from the uncloned "founder" HeLa cells and from five sublines have been determined. These sequences all carry a common "core" of 38 single basepair alterations relative to the revised Cambridge Reference Sequence (CRS). The HeLa mitochondrial genome is of African descent and it is a member of the African L3 haplogroup. The sequence of the HeLa mtDNA resolves the uncertainty surrounding the mosaic composition of the original CRS for human mtDNA. Most importantly, we detected a total of eight polymorphisms that have arisen in the mtDNA coding region of different HeLa sublines. These observations suggest that HeLa mtDNA has a high rate of sequence divergence, relative to the phylogenetically-derived divergence rate for mtDNAs in the human population, which results from a relaxation of negative selection against the fixation of deleterious mutations. Furthermore, this high frequency of polymorphisms in HeLa mtDNA may reflect a process similar to the accumulation of somatic mtDNA mutations in human cancers. Preliminary analysis of single-cell derived subclone lines revealed the occurrence of another polymorphism and provided evidence for a large number of mtDNA segregation units.
authors.affiliation: MitoKor, 11494 Sorrento Valley Road, San Diego, CA 92121, USA.
authors.forename: Corinna
authors.initials: C
authors.lastname: Herrnstadt
authors.forename: Gwen
authors.initials: G
authors.lastname: Preston
authors.forename: Richard
authors.initials: R
authors.lastname: Andrews
authors.forename: Patrick
authors.initials: P
authors.lastname: Chinnery
authors.forename: Robert N
authors.initials: RN
authors.lastname: Lightowlers
authors.forename: Douglass M
authors.initials: DM
authors.lastname: Turnbull
authors.forename: Iwona
authors.initials: I
authors.lastname: Kubacka
authors.forename: Neil
authors.initials: N
authors.lastname: Howell
mesh_terms: D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic
chemical_list: D004272:DNA, Mitochondrial