QTLs for Alcohol Consumption by HXB/BXH RI Rat Strains. Behavioral QTLs (bQTLs) were calculated using the data shown in Figure 1. Individual values were not included if they were more than two standard deviations from the strain mean. The STAR Consortium SNP markers (The STAR Consortium, 2008) were used for this analysis. There were 21 RI strains and the two progenitor strains that had both alcohol consumption and SNP data. Strain means for alcohol consumption were used in a marker regression QTL analysis, which was conducted using the R/qtl package in R. The 20 Mb region around the suggestive markers was used as the bQTL interval shown.