a) Basal mRNA levels of Nin were significantly greater in D2 mice than B6 mice (*p<0.01, n=8 per group, Student’s t-test between strain) as confirmed by qRT-PCR. Nin expression was normalized to Ppp2r2a. b) Pyrosequencing of NAc samples of B6D2F1/J hybrid mice for an amplicon of Nin containing two progenitor SNPs confirmed cis regulation of Nin (*p<0.01, n=2 pooled per sample, n= 3 per group, n >4000 reads per group, Student’s t-test). c-d) Immunoblotting of NAc samples from untreated B6 and D2 mice revealed significantly higher levels of two isoforms (NIN4 and NIN5, ~120 KDa) in D2 mice compared to B6 (*p<0.05, Student’s t-test, n=5/strain). D2 mice also show a trend for higher levels of NIN6, NIN8, and NIN10 isoforms (p=0.1703, p=0.0589, p=0.1516, respectively, Student’s t-test). NIN levels were normalized to ACTB protein levels.