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The Light Wavelength Affects the Ontogeny of Clock Gene Expression and Activity Rhythms in Zebrafish Larvae.

Di Rosa V, Frigato E, López-Olmeda JF, Sánchez-Vázquez FJ, Bertolucci C - PLoS ONE (2015)

Bottom Line: The aim of this research was to determine the effect of light of different wavelengths (white, blue and red) on the onset of locomotor activity and clock gene (per1b, per2, clock1, bmal1 and dbp) expression rhythms.Curiously, bmal1 showed consistent rhythmic expression from embryonic stage (0 dpf).Summarizing, the data revealed that daily rhythms appeared earlier in the larvae reared under LDB than in those reared under LDW and LDR.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia Spain.

ABSTRACT
Light plays a key role in synchronizing rhythms and setting the phase of early development. However, to date, little is known about the impact of light wavelengths during the ontogeny of the molecular clock and the behavioural rhythmicity. The aim of this research was to determine the effect of light of different wavelengths (white, blue and red) on the onset of locomotor activity and clock gene (per1b, per2, clock1, bmal1 and dbp) expression rhythms. For this purpose, 4 groups of zebrafish embryo/larvae were raised from 0 to 7 days post-fertilization (dpf) under the following lighting conditions: three groups maintained under light:dark (LD) cycles with white (full visible spectrum, LDW), blue (LDB), or red light (LDR), and one group raised under constant darkness (DD). The results showed that lighting conditions influenced activity rhythms. Larvae were arrhythmic under DD, while under LD cycles they developed wavelength-dependent daily activity rhythms which appeared earlier under LDB (4 dpf) than under LDW or LDR (5 dpf). The results also revealed that development and lighting conditions influenced clock gene expression. While clock1 rhythmic expression appeared in all lighting conditions at 7 dpf, per1b, per2 and dbp showed daily variations already at 3 dpf. Curiously, bmal1 showed consistent rhythmic expression from embryonic stage (0 dpf). Summarizing, the data revealed that daily rhythms appeared earlier in the larvae reared under LDB than in those reared under LDW and LDR. These results emphasize the importance of lighting conditions and wavelengths during early development for the ontogeny of daily rhythms of gene expression and how these rhythms are reflected on the behavioural rhythmicity of zebrafish larvae.

No MeSH data available.


Related in: MedlinePlus

A circular representation of the phases of zebrafish activity across the 24 hours from 5 to 7 dpf under LDW, LDB and LDR.The dots represent the acrophase of each zebrafish larvae. The arrows indicate the average phases represented as vector and in each circle the mean vector length (r) and the mean acrophases (a) in ZT are reported. The circle inside each panel represents critical values of the Rayleigh test (p<0.05) and the coloured part show the duration of light phase (ZT 0–12). The dotted lines represent the confidence intervals.
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pone.0132235.g002: A circular representation of the phases of zebrafish activity across the 24 hours from 5 to 7 dpf under LDW, LDB and LDR.The dots represent the acrophase of each zebrafish larvae. The arrows indicate the average phases represented as vector and in each circle the mean vector length (r) and the mean acrophases (a) in ZT are reported. The circle inside each panel represents critical values of the Rayleigh test (p<0.05) and the coloured part show the duration of light phase (ZT 0–12). The dotted lines represent the confidence intervals.

Mentions: To verify the accuracy of the entrained rhythm we estimated the time of acrophases respect to the lights on (ZT0) in all groups from 5 to 7 dpf. Using a circular statistic approach, we showed that the distribution of acrophases deviated from uniform in LDW, LDB and LDR groups (Fig 2; Rayleigh test, 0.05<p<0.001), and the mean acrophases fell between ZT 2 and 7 (Fig 2). The distribution of acrophases from 5 to 7 dpf differed only between LDB and LDR groups (Mardia-Watson-Wheeler Test: LDW: W4 = 5.4, p<0.05; LDB: W4 = 38.9, p<0.0001; LDR: W4 = 45.3, p<0.0001). The distribution among groups did not differ at 7 dpf (Mardia-Watson-Wheeler Test: W4 = 4.5, p>0.3), and the mean acrophases fell at ZT 03:18–04:36 (Fig 2).


The Light Wavelength Affects the Ontogeny of Clock Gene Expression and Activity Rhythms in Zebrafish Larvae.

Di Rosa V, Frigato E, López-Olmeda JF, Sánchez-Vázquez FJ, Bertolucci C - PLoS ONE (2015)

A circular representation of the phases of zebrafish activity across the 24 hours from 5 to 7 dpf under LDW, LDB and LDR.The dots represent the acrophase of each zebrafish larvae. The arrows indicate the average phases represented as vector and in each circle the mean vector length (r) and the mean acrophases (a) in ZT are reported. The circle inside each panel represents critical values of the Rayleigh test (p<0.05) and the coloured part show the duration of light phase (ZT 0–12). The dotted lines represent the confidence intervals.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492954&req=5

pone.0132235.g002: A circular representation of the phases of zebrafish activity across the 24 hours from 5 to 7 dpf under LDW, LDB and LDR.The dots represent the acrophase of each zebrafish larvae. The arrows indicate the average phases represented as vector and in each circle the mean vector length (r) and the mean acrophases (a) in ZT are reported. The circle inside each panel represents critical values of the Rayleigh test (p<0.05) and the coloured part show the duration of light phase (ZT 0–12). The dotted lines represent the confidence intervals.
Mentions: To verify the accuracy of the entrained rhythm we estimated the time of acrophases respect to the lights on (ZT0) in all groups from 5 to 7 dpf. Using a circular statistic approach, we showed that the distribution of acrophases deviated from uniform in LDW, LDB and LDR groups (Fig 2; Rayleigh test, 0.05<p<0.001), and the mean acrophases fell between ZT 2 and 7 (Fig 2). The distribution of acrophases from 5 to 7 dpf differed only between LDB and LDR groups (Mardia-Watson-Wheeler Test: LDW: W4 = 5.4, p<0.05; LDB: W4 = 38.9, p<0.0001; LDR: W4 = 45.3, p<0.0001). The distribution among groups did not differ at 7 dpf (Mardia-Watson-Wheeler Test: W4 = 4.5, p>0.3), and the mean acrophases fell at ZT 03:18–04:36 (Fig 2).

Bottom Line: The aim of this research was to determine the effect of light of different wavelengths (white, blue and red) on the onset of locomotor activity and clock gene (per1b, per2, clock1, bmal1 and dbp) expression rhythms.Curiously, bmal1 showed consistent rhythmic expression from embryonic stage (0 dpf).Summarizing, the data revealed that daily rhythms appeared earlier in the larvae reared under LDB than in those reared under LDW and LDR.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia Spain.

ABSTRACT
Light plays a key role in synchronizing rhythms and setting the phase of early development. However, to date, little is known about the impact of light wavelengths during the ontogeny of the molecular clock and the behavioural rhythmicity. The aim of this research was to determine the effect of light of different wavelengths (white, blue and red) on the onset of locomotor activity and clock gene (per1b, per2, clock1, bmal1 and dbp) expression rhythms. For this purpose, 4 groups of zebrafish embryo/larvae were raised from 0 to 7 days post-fertilization (dpf) under the following lighting conditions: three groups maintained under light:dark (LD) cycles with white (full visible spectrum, LDW), blue (LDB), or red light (LDR), and one group raised under constant darkness (DD). The results showed that lighting conditions influenced activity rhythms. Larvae were arrhythmic under DD, while under LD cycles they developed wavelength-dependent daily activity rhythms which appeared earlier under LDB (4 dpf) than under LDW or LDR (5 dpf). The results also revealed that development and lighting conditions influenced clock gene expression. While clock1 rhythmic expression appeared in all lighting conditions at 7 dpf, per1b, per2 and dbp showed daily variations already at 3 dpf. Curiously, bmal1 showed consistent rhythmic expression from embryonic stage (0 dpf). Summarizing, the data revealed that daily rhythms appeared earlier in the larvae reared under LDB than in those reared under LDW and LDR. These results emphasize the importance of lighting conditions and wavelengths during early development for the ontogeny of daily rhythms of gene expression and how these rhythms are reflected on the behavioural rhythmicity of zebrafish larvae.

No MeSH data available.


Related in: MedlinePlus