Sensory neurons degenerate upon UVC exposure.

(A) Representation of damage in sensory neurons after UVC exposure. 3D reconstruction of confocal fluorescence from sensory neurons in a PVD::GFP (F49H12.4::GFP) transgenic line (NC1686). GFP-labeled sensory neurons were observed at 10 min and 4h after 254- and 222-UVC exposure (200 and 400 J/m2). (B and C) The number of GFP dots along sensory neurons. GFP dots were counted by looking with adding the mark on the pictures opened by ImageJ software. Box plots show minimum, 25th percentile, median, 75th percentile, and maximum. Inside line and x indicate the value of median and average, respectively. a and b indicate a significant difference between indicating two groups (one-way ANOVA followed by Dunnett’s method) (P < 0.05).</p

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Effects of 254- or 222-UVC exposure on <i>C</i>. <i>elegans</i> motility.

(A) Schematic cartoon of experimental design. Transferred five adults to new NGM plates seeded with Escherichia coli. One day later, removed the adults and remained eggs. 7 days later, took the adult worms and put them into PBS buffer and counted the thrashing number per minute. (B) The number of thrashes in 1 min was counted for each worm (n = 10–28 worms) at 0 min, 10 min, 4 h, and 24 h after UVC exposure. The purple line and red line indicate the thrashing rate of 254-UVC and 222-UVC irradiated worms, respectively. Colored solid and dotted lines indicate 200 and 400 J/m2 irradiation, respectively. Error bars indicate the SE for 10–28 worms. a and b indicate a significant difference between indicating two groups (one-way ANOVA followed by Dunnett’s method) (P P < 0.05).</p

Effects of 254- and 222-UVC exposure on <i>C</i>. <i>elegans</i> hatching rate.

(A) Schematic cartoon of experimental design. Five young gravid hermaphrodites (WT) were transferred to new NGM plates seeded with Escherichia coli and were irradiated with 50–200 J/m2 of 254- or 222-UVC. 4 h later, removed the adults and counted the number of laying eggs. 12 h later, counted the number of not-hatched eggs, and the hatching rate was calculated (hatching rate = the number of hatching eggs / the number of laid eggs x 100) (n = 60–200). (B) Survival of the eggs laid by WT hermaphrodites after 254- or 222-UVC. The purple line and red line indicate 254-UVC and 222-UVC survival, respectively. Error bars indicate the SE of six independent experiments. ****P < 0.0001 versus 254-UVC (two-tailed Student’s test). (C) The chromosome structure in full-grown oocytes (left panel) at diakinesis stage and the nuclei of early fertilized eggs (right panel) in the uterus 4 h later after UVC irradiation, was examined with DAPI staining. Bar indicates 10 μm.</p

<i>C</i>. <i>elegans</i> structure.

(A) C. elegans body plane, showing the side view. (B) Head section of C. elegans (cross section of “a” in Fig 6A). Orange circles show CEP neurons. Scale bar, 1.0 μm. (C) Cross-section of the midbody region (cross section of “b” in Fig A). Blue circles and lines show PVD neurons. Purple and pink arrows show 254- and 222-UVC, respectively. Images modified from those found at www.wormatlas.org. Altun, Z.F., L.A. Herndon, C. Crocker, R. Lints, and D.H. Hall (eds), 2002–2015 WormAtlas. Available at: http://www.wormatlas.org.</p

Frequency of CPDs induced by UVC irradiation on lambda DNA.

(A) Detection of CPD levels on lambda DNA. Lambda DNA was irradiated by 254- or 222-UVC and the DNA was incubated with (+) or without (-) T4 endonuclease. DNA was analyzed in an alkaline gel. M, size marker (lambda-Hind III cut). (B) Representation of DNA bands in the form of peaks. (C) The frequency of CPDs is calculated by the frequency of CPDs untreated with T4 endonuclease has been subtracted from the frequency of CPD treated with the enzyme. The purple and red lines indicate DNA damage frequency induced by 254-UVC and by 222-UVC, respectively. Error bars indicate the SE of three independent experiments. *P < 0.05 versus 254-UVC (one-tailed Student’s test).</p

Spectra of the light sources used in this study.

(A) Spectra of a germicidal lamp (254-UVC; Toshiba Electric) at a distance of 20 cm. (B) Spectra of a 15 W KrCl excimer lamp (222-UVC) at a distance of 12.5 cm. 254- and 222-UVC sources emitted radiation at 6.8 and 1.7 J/m2 s, respectively. (TIF)</p

Relationship between light intensity and penetration depth for 254- and 222-UVC.

The light intensity exponentially decays when it passes through a biomaterial. Blue line show the light intensity of 254-UVC, and orange line show the light intensity of 222-UVC, calculated with the absorption coefficient from the data [34]. Dot lines indicate where the light reaches the beginning and end of the tissue. Blue and orange arrows indicate the UVC energy absorbed in the relevant region for 254-UVC and 222-UVC, respectively. Gray areas show where neurons (CEP, PVD), and eggs are located.</p

Dopaminergic neurons degenerate upon strong 254-UVC exposure.

(A) Representation of damage in dopaminergic neurons after UVC exposure. 3D reconstruction of confocal fluorescence from head dopamine neurons in a pdat-1::GFP transgenic line (TG2435). GFP-labeled dopaminergic neurons were observed 4 h after 254-UVC exposure (2000 and 4000J/m2). (B) The number of GFP dots along CEP dendrites in the head zone. GFP dots were counted by looking with adding the mark on the pictures opened by ImageJ software. Box plots show minimum, 25th percentile, median, 75th percentile, and maximum. a and b indicate a significant difference between indicating two groups (one-way ANOVA followed by Dunnett’s method) (P < 0.05).</p

Dopaminergic neurons degenerate upon UVC exposure.

(A) Representation of damage in dopaminergic neurons after UVC exposure. 3D reconstruction of confocal fluorescence from head dopamine neurons in a pdat-1::GFP transgenic line (TG2435). GFP-labeled dopaminergic neurons were observed 10 min and 4 h after 254-and 222-UVC exposure (200 and 400 J/m2). (B and C) The number of GFP dots along CEP dendrites in the head zone. GFP dots were counted by looking with adding the mark on the pictures opened by ImageJ software. Box plots show minimum, 25th percentile, median, 75th percentile, and maximum. Inside line and x indicate the value of median and average, respectively. a and b indicate a significant difference between indicating two groups (one-way ANOVA followed by Dunnett’s method) (P < 0.05).</p