Lamin A/C is expressed in pluripotent mouse embryonic stem cells

The pluripotent nature of embryonic stem cells (ESC) is associated with a dynamic open chromatin state and an irregular nuclear shape. It has been postulated that the absence of lamin A/C contributes to these features. However, we show that mouse ESCs express low, yet readily detectable, amounts of lamin A/C at both the RNA and protein levels. Full-length transcripts of both isoforms were readily detected by q-PCR and deep RNA sequencing. Additionally, protein expression was validated in multiple primary and established ESC lines by immunoblotting using several independent antibodies. Immunofluorescence labeling showed localization of lamin A/C at the nuclear periphery of all Oct4/Nanog double-positive ESC lines examined, as well as in the inner cell mass of blastocysts. Our results demonstrate ESCs do express low levels of lamin A/C, thus models linking pluripotency and nuclear dynamics with the absence of lamin A/C need to be revisited.