Skip to main content
. 2019 Oct 4;222(19):jeb196493. doi: 10.1242/jeb.196493

Fig. 1.

Fig. 1.

Generation and expansion of thirteen-lined ground squirrel induced pluripotent stem cells (iPSCs). (A) Lentivirus transfection of thirteen-lined ground squirrel primary neural precursor cells (from postnatal day 2 animals) with the OSKM (OCT4, SOX2, KLF4 and cMYC) transcription factor genes led to the formation of dome-shaped colonies that could not be expanded (i.e. displayed slow/no growth and therefore were not passaged). Sendai virus transfection of the primary cells with OSKM genes for 24 h led to the formation of flat colonies that stained positive for the pluripotency markers OCT4 and NANOG, and that could be passaged by using dispase or scratching with pipette tips. D0, day 0 of culture; D2, day 2 of culture, etc. (B,C) Culture medium (B) and cell adhesion (C) strongly affect the expansion and maintenance of thirteen-lined ground squirrel iPSC colonies. E8 and mTeSR, standard defined media optimized for human iPSC and embryonic stem cell cultures; DMEM, Dulbecco's modified Eagle medium; KSR, knockout serum replacement; MEF, mouse embryonic fibroblasts. Scale bars: 200 µm (A); 400 µm (B,C).