in alcoholic-derived neural cultures by 24%. The 3- to 8-fold range in basal expression among iPSC lines (Figure 1D–F) could reflect different rates of neural maturation of individual lines and/or individual differences in donor genome between lines. The variation in expression change between lines after chronic alcohol exposure is more modest and may reflect genomic variation, as it represents a within-subject (culture) difference. The cell lines used for gene expression analysis included independently generated clones derived from 5 CTL and 2 AD donors. Examination of the concordance for the direction of change in RNA following alcohol exposure (increase or decrease relative to sham) for the 7 pairs of replicate clones derived from individual donors for the three GABAA subunit genes showed directional concordance for 16 and non-concordance for 5 clones, suggesting that individual genomic variation between subjects may contribute to observable variation in gene expression response. Of the 16 concordant expression changes among pairs, 15 were upregulated and 1 was downregulated.
