ii. Transcripts enriched in control vs BP iPSC Forty-six transcripts were expressed 1.5-fold or higher in iPSC from control vs BP individuals, including genes involved in cell polarity and in lineage differentiation, including the TOR complex2 factor RICTOR, which regulates cell growth. There was one cluster of transforming growth factor-β-related transcripts that was significantly increased (Table 3ii). Members of this cluster included GDF3 and INHBE that have been associated with proliferation and pluripotency and are expressed in the ICM and/or in hESC,52 whereas LEFTY1 and LEFTY2 are involved in nodal inhibition, neural induction and early embryo patterning.53 None was previously associated with psychiatric or human neurodevelopmental disorders. These data indicate that iPSC from BP and control cells are strikingly similar in their transcriptional repertoire. No genes associated with the core regulatory mechanisms that maintain pluripotency were differentially expressed in these two populations.
