Figure 2 .

Drosophila glypican homologs regulate behavioral responses to acute and repeated ethanol exposure. (A) Simplified diagram of the dlp locus. Coding regions are indicated with shaded boxes. The transposon insertion allele dlp^f03537 is located in the first intron. Probes for qPCR span the last intron. (B) Ethanol-stimulated locomotion of flies homozygous (left) or heterozygous (right) for f03537 continuously exposed to 47% ethanol vapor (0–25 min, bar on horizontal axis). Control in all experiments was the genetic background strain. Statistical significance (two-sample t-test) was assessed by comparison of the total distance traveled during the hyperactive phase (2–25 min). f03537: n = 5, f03537/+: n = 8. (C) Exposure scheme for inducing and detecting ethanol rapid tolerance. Flies were exposed twice to 67% ethanol vapor with 4 hr between the start of exposures 1 and 2. (D) Sedation sensitivity and tolerance of flies heterozygous for f03537. ST50 is the time to 50% sedation, and sedation tolerance is the difference between the ST50 of exposure 2 (e2) and 1 (e1). Sensitivity and sedation are illustrated by the horizontal bar graphs. ^*P = 0.0206, ^**P = 0.0022, two-sample t-test. n = 9. (E) Simplified diagram of the dally locus. (F) Ethanol-stimulated locomotion of flies homozygous (left) or heterozygous (right) for MB950 continuously exposed to 47% ethanol vapor (0–25 min). MB950: n = 7, MB950/+: n = 11. (G) Sedation sensitivity and tolerance of flies homozygous for MB950. ^***P = 0.0002, two-sample t-test. n = 7. Ethanol absorption was unaltered in dlp (control: 24.6 mM, f03537/+: 24.2 mM, P = 0.8726, two-sample t-test, n = 6) and dally mutant flies (control: 29.5 mM, MB950: 31.7 mM, P = 0.5231, two-sample t-test, n = 4).