Trans eQTL enriched loci, referred to as trans-bands, were detected by splitting the genome into 10 Mb bins and counting the number of suggestive eQTL that mapped to each. In order to determine whether a particular genome bin harbored more eQTL than would be expected by chance, we performed 10,000 permutations, each involving random assignment of all eQTL to a genetic marker and recording the number of mappings at the most populous bin. Observed trans-bands were deemed significant if they exceeded the 95th percentile of the distribution of peak trans-bands captured from each permutation. To facilitate the search for candidate regulators underlying these eQTL enriched regions, we defined support intervals for each of the major trans-bands by aggregating the support intervals calculated for the individual eQTL comprising each trans-band. Trans-band support intervals were defined as the chromosomal regions flanked by genetic markers that were included in at least 80% of the trans-band member's individual support intervals.
