"Chronic exposure to nicotine at the micromolar range induced aberrant gene expressions in wt C. elegans across all dosed concentrations. Fig. 4 shows the fold change in gene expression of the 18 tested genes, varying from 12.5-fold down-regulation (
old-1) to 138.1-fold up-regulation (
hlh-14). Statistical analysis indicate that there were 10 tested genes expressed aberrantly in response to at least one dosage of nicotine. These 10 genes are
egl-10,
egl-44,
hlh-14,
ric-3,
unc-103,
unc-50,
unc-68,
sod-1,
oxi-1, and
old-1. Among the 10 genes, 8 genes (
egl-10,
egl-44,
hlh-14,
ric-3,
unc-103,
unc-50,
unc-68, and
oxi-1) were significantly up-regulated, 2 genes (
sod-1 and
old-1) were significantly down-regulated. Gene regulation is the most active at two low nicotine treatment groups; 3 (
egl-44,
ric-3, and
old-1) and 7 tested genes (
egl-10,
hlh-14,
unc-103,
unc-50,
unc-68,
sod-1, and
oxi-1) were differentially expressed at 1 ppm and 3.16 ppm treatment groups, respectively. In contrast, only 3 (
egl-44,
ric-3, and
old-1) and 1 tested genes (
ric-3) were significantly changed at 10 ppm and 31.6 ppm treatment groups, respectively. Changes in gene expressions were the most significant under 3.16 ppm nicotine exposure; six genes (
egl-10,
hlh-14,
unc-103,
unc-50,
unc-68, and
oxi-1) displayed at least 10-fold significant up-regulation."