Figure 1

Genetic characterization and locomotor activity of mito-mice before and after cognitive analyses. (A) Gene map of mouse wild-type mtDNA (black) and ΔmtDNA (gray). The white arc in the ΔmtDNA indicates the deleted region expanded from the tRNA^Lysto ND5 genes. (B) Two groups of mito-mice were used in the experiment. Mito-mouse population (n = 24) was divided into two groups, low (n = 10), carrying 50% or less ΔmtDNA in their tails (at age 4 weeks), and high (n = 14), carrying more than 50%. The two groups shared the same nuclear genome background (C57BL/6). (C-F) To examine locomotor activity in the low group (black), and high (gray) group, four kinds of traditional behavioral test, the open field test (C) (P = 0.1638 in before, P = 0.1502 in after), elevated plus maze test (D) (P = 0.9589 in before, P = 0.5703 in after), light-dark transition test (E) (before: P = 0.8434 in light side, P = 0.1114 in dark side; after: P = 0.1379 in light side, P = 0.8239 in dark side), and Porsolt forced-swim test (F) (before: P = 0.3685 in day 1, P = 0.2449 in day 2; after: P = 0.7663 in day 1, P = 0.7735 in day 2), were performed before and after cognitive analyses. Results of total distance analyses indicated that there were no differences in locomotor activity between the low and high groups. All values are means ± SE.