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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

Daily expression levels at 0, 3, 7 dpf of clock1 bmal1, per1b, per2 and dbp under different lighting conditions.The data are expressed as mean ± SEM. The letters above each bar indicate significant differences for each condition among the days (one-way-ANOVA, p<0.05). The symbols on the top indicates statistically differences between the lighting conditions (two-way-ANOVA, Tukey’s post-hoc test, p<0.05).
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pone.0132235.g005: Daily expression levels at 0, 3, 7 dpf of clock1 bmal1, per1b, per2 and dbp under different lighting conditions.The data are expressed as mean ± SEM. The letters above each bar indicate significant differences for each condition among the days (one-way-ANOVA, p<0.05). The symbols on the top indicates statistically differences between the lighting conditions (two-way-ANOVA, Tukey’s post-hoc test, p<0.05).

Mentions: The comparison of mean expression levels of each gene showed differences depending on the experimental conditions (Fig 5). For instance, the highest levels of clock1, bmal1 and per2 expression levels were at 0 dpf (one-way ANOVA, p<0.01; Fig 5A, 5B and 5D). Differently, per1b and dbp showing the highest values at 3 and 7 dpf (one-way ANOVA, p<0.05; Fig 5C and 5E). The daily mean expression level of dbp was higher at 3 and 7 dpf respect to 0 dpf in LDW, LDR and DD (two-way ANOVA, p<0.001; Fig 5E), whereas in LDB the mean levels did not change during the first week of life (Tukey’s post-hoc, p<0.05; Fig 5E). Clock1 relative expression was mainly influenced by LDB (Tukey’s post-hoc, p<0.008, Fig 5A). No statistical differences were detectable for both bmal and dbp among the lighting conditions (two-way ANOVA, p<0.2, Fig 5B and 5E). LDB and DD influenced the per1b mean expression differently from LDW and LDR (Tukey’s post-hoc, p<0.03; Fig 5C). The effect LDW on Per2 expression is different from DD but not from LDB and LDR (Tukey’s post-hoc, LDW vs DD: p<0.01, LDW vs LDB-LDR: p<0.6, LDB-LDR vs DD: p<0.3; Fig 5D).


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)

Daily expression levels at 0, 3, 7 dpf of clock1 bmal1, per1b, per2 and dbp under different lighting conditions.The data are expressed as mean ± SEM. The letters above each bar indicate significant differences for each condition among the days (one-way-ANOVA, p<0.05). The symbols on the top indicates statistically differences between the lighting conditions (two-way-ANOVA, Tukey’s post-hoc test, p<0.05).
© Copyright Policy
Related In: Results  -  Collection

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

pone.0132235.g005: Daily expression levels at 0, 3, 7 dpf of clock1 bmal1, per1b, per2 and dbp under different lighting conditions.The data are expressed as mean ± SEM. The letters above each bar indicate significant differences for each condition among the days (one-way-ANOVA, p<0.05). The symbols on the top indicates statistically differences between the lighting conditions (two-way-ANOVA, Tukey’s post-hoc test, p<0.05).
Mentions: The comparison of mean expression levels of each gene showed differences depending on the experimental conditions (Fig 5). For instance, the highest levels of clock1, bmal1 and per2 expression levels were at 0 dpf (one-way ANOVA, p<0.01; Fig 5A, 5B and 5D). Differently, per1b and dbp showing the highest values at 3 and 7 dpf (one-way ANOVA, p<0.05; Fig 5C and 5E). The daily mean expression level of dbp was higher at 3 and 7 dpf respect to 0 dpf in LDW, LDR and DD (two-way ANOVA, p<0.001; Fig 5E), whereas in LDB the mean levels did not change during the first week of life (Tukey’s post-hoc, p<0.05; Fig 5E). Clock1 relative expression was mainly influenced by LDB (Tukey’s post-hoc, p<0.008, Fig 5A). No statistical differences were detectable for both bmal and dbp among the lighting conditions (two-way ANOVA, p<0.2, Fig 5B and 5E). LDB and DD influenced the per1b mean expression differently from LDW and LDR (Tukey’s post-hoc, p<0.03; Fig 5C). The effect LDW on Per2 expression is different from DD but not from LDB and LDR (Tukey’s post-hoc, LDW vs DD: p<0.01, LDW vs LDB-LDR: p<0.6, LDB-LDR vs DD: p<0.3; Fig 5D).

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