Fig. 1.  Genomic structure of the TRESK genetic locus and genotyping results confirming TRESK gene knockout. (A ) Basic structure of TRESK gene and a schematic of the targeting vector used to transfect mouse strain C57BL6 embryonic stem cells. For each exon, an open box represents an untranslated region and a closed box represents a protein-coding region. P1 and P2 indicate the location of primers used for genotyping. Knockout (KO)/+neo indicates the structure of the TRESK gene locus after successful homologous recombination with the targeting vector and KO/−neo shows the structure after deletion of the neo cassette via  the action of Cre recombinase. AmpR = ampicillin-resistant gene (β-lactamase), neo = neomycin resistance gene, lox P = flanking sequences targeting the deletion of intervening sequence by Cre. (B ) Representative agarose gel of genotyping results (ethidium bromide fluorescence). lane 1 = 1 kilobase (kb) DNA ladder, lane 9 = 0.1 kb DNA ladder. The symbol +/+, +/−, or −/− below each lane identifies a banding pattern indicating wild-type, heterozygous, or homozygous genotype, respectively.