from a large number of inbred strains. This approach has identified several genes involved in opioid maladaptive responses [12–14]. However, the lack of genome-wide sequence information for an adequate numbers of inbred mouse strains has previously limited the power of this technique, as have limitations in the tools that are required to analyze the large amount of sequence information. To overcome these limitations, we have developed a HBCGM method that uses a whole-genome SNP database that was generated by analysis of whole genome sequence data for 25 inbred strainsa. Here, we use this new tool to address the public health problems associated with chronic opioid use, and identify a novel gene that is involved in maladaptive opioid responses.
