Preference selection had a marked effect on alternative splicing. The mammalian genome contains over 20 000 protein-coding genes and alternative splicing produces approximately 100 000 intermediate to highly expressed transcripts with the greatest diversity found in brain (Calarco et al. 2011; Li et al. 2007; Pan et al. 2008). There is evidence that drugs of abuse including alcohol affect alternative splicing and/or that the responses of drugs of abuse are transcript dependent (Acosta et al. 2011; Bulwa et al. 2011; Farris & Mayfield 2014; Glatt et al. 2011; Jin & Woodward 2006; Lee et al. 2014; Maiya et al. 2012; Raeder et al. 2008; Rothenfluh et al. 2006; Wernicke et al. 2010). We and others (see Iancu et al. 2015 and references therein) have observed that coordinated splicing has network properties amenable to analysis using tools such as WGCNA. While exon usage patterns can be represented in several ways, we have chosen a method that utilizes Mantel correlations of Canberra distance matrices (Iancu et al. 2015). This method detects exon inclusion rates but does not provide information on isoform identity, which requires greater read depth than the current study (Lee et al. 2014).
