Mitochondrial DNA sequencing of HepaRG and SJCRH30 human cell lines

In comparison to the revised Cambridge Reference Sequence (NC_012920), HepaRG and SJCRH30 mtDNAs each contain 14 nucleotide variations. In addition to an insertion of a cytosine at position 315 (315insC), the mtDNA sequences from both cell types share six common polymorphisms. Heteroplasmic variants were identified in both cell types and included the identification of the 315insC variant at 42 and 75% heteroplasmy in HepaRG and SJCRH30 mtDNAs respectively. Additionally, a novel heteroplasmic G13633A substitution in the HepaRG ND5 gene was detected at 33%. Previously reported cancer-associated mtDNA variants T195C and T16519C were identified in SJCRH30, both at 100% homoplasmy, while HepaRG mtDNA harbors a known prostate cancer-associated T6253C substitution at near homoplasmy, 95%. Based on our sequencing analysis, HepaRG mtDNA is predicted to lie within haplogroup branch H15a1 while SJCRH30 mtDNA is predicted to localize to H27c.

与修正版剑桥参考序列（NC_012920）相比，HepaRG与SJCRH30的线粒体DNA（mitochondrial DNA, mtDNA）各携带14处核苷酸变异。除在315位点存在胞嘧啶插入（315insC）外，两种细胞的线粒体DNA序列共存在6处共同多态性位点。两种细胞系中均检测到异质性变异，其中315insC变异在HepaRG和SJCRH30线粒体DNA中的异质性比例分别为42%与75%。此外，在HepaRG的ND5基因中检测到一处全新的异质性G13633A替换，其异质性比例为33%。此前已报道的癌症相关线粒体DNA变异T195C与T16519C在SJCRH30中被检出，二者均为100%同质性；而HepaRG线粒体DNA携带一处已知的前列腺癌相关T6253C替换，其异质性比例达95%，接近完全同质性。基于本次测序分析，HepaRG线粒体DNA被归类至单倍群分支H15a1，而SJCRH30线粒体DNA则归属单倍群H27c。