Use of a Sendai virus-based vector for efficient transduction of pinniped fibroblasts

Generation of induced pluripotent stem (iPS) cells expanded possibilities of pluripotency and early development studies. Generation of order Carnivora iPS cells from dog (Canis lupus familiaris), snow leopard (Panthera uncia), and American mink (Neovison vison) was previously reported. The aim of the current study was to examine conditions of pinniped fibroblast reprogramming. Pinnipeds are representatives of the suborder Caniformia sharing conservative genomes. There are several ways to deliver reprogramming transcription factors: RNA, proteins, plasmids, viral vectors etc. The most effective delivery systems for mouse and human cells are based on viral vectors. We compared a lentiviral vector which integrates into the genome and a Sendai virus-based vector, CytoTune EmGFP Sendai Fluorescence Reporter. The main advantage of Sendai virus-based vectors is that they do not integrate into the genome. We performed delivery of genetic constructions carrying fluorescent proteins to fibroblasts of seven Pinnipeds: northern fur seal (Callorhinus ursinus), Steller sea lion (Eumetopias jubatus), walrus (Odobenus rosmarus), bearded seal (Erignathus barbatus), Baikal seal (Pusa sibirica), ringed seal (Phoca hispida), and spotted seal (Phoca largha). We also transduced American mink (N. vison), human (Homo sapiens), and mouse (Mus musculus) fibroblasts as a control. We showed that the Sendai virus-based transduction system provides transgene expression one-two orders of magnitude higher than the lentiviral system at a comparable multiplicity of infection. Also, transgene expression after Sendai virus-based transduction is quite stable and changes only slightly at day four compared to day two. These data allow us to suggest that Sendai virus-based vectors are preferable for generation of Pinniped iPS cells.