Larks, owls, swifts, and woodcocks among fruit flies: differential responses of four heritable chronotypes to long and hot summer days

Figures & data

Figure 1 Twenty-four h time courses in the fruit fly under four experimental conditions. Data of each of four experiments were averaged within and across four strains.

Notes: Upper and lower graphs: Locomotor activity and sleep, respectively. Left and right graphs: Exposure to constant darkness (DD in winter and summer) and long photoperiod (LD20:4 at 20°C and at 29°C), respectively. Black line on the x-axis indicates the interval of darkness, either 24 h for DD or 4 h in the middle of the night (between 23:00 and 3:00 of local clock time).
Abbreviations: SEM, standard error of mean; h, clock hour; DD, constant darkness.

Figure 2 Twenty-four h time courses in four chronotypes under different lighting conditions. Data of experiments under constant darkness (DD) and long photoperiod (LD20:4) were averaged within each of four strains (G10, U28, G15, and F30). Upper and lower graphs: Locomotor activity and sleep, respectively. Left and right graphs: Exposure to DD and LD20:4, respectively.

Note: Black line on the x-axis indicates the interval of darkness, either 24 h for DD or 4 h in the middle of the night (between 23:00 and 3:00 of local clock time).
Abbreviations: SEM, standard error of mean; h, clock hour; DD, constant darkness; EM, early morning; LM, late morning; MD, middle of the day; EE, early evening; LE, late evening; MN, middle of the night.

Figure 3 Twenty-four h time courses in four chronotypes at 20°C and 29°C. Data of flies from each of two experiments with exposure to long photoperiod were averaged within each of two strains (G10 and U28). Upper and lower graphs: Locomotor activity and sleep in G10 (left graphs) and U28 (right graphs) and in G15 (left graphs) and F30 (right graphs), respectively.

Note: Black line on the x-axis indicates 4 h interval of darkness in the middle of the night (between 23:00 and 3:00 of local clock time).
Abbreviations: SEM, Standard error of mean; h, clock hour.

Table 1 Results of two-way rANOVAs with repeated measure “Time” and independent factor “Strain”

Factor	Measure	DD				Light–dark cycle (LD20:4)
		Winter		Summer		20°C		29°C
		Activity	Sleep	Activity	Sleep	Activity	Sleep	Activity	Sleep
“Strain” (G10, G15, U28, F30)	F	39.202	38.245	4.181	21.593	6.891	8.149	14.656	18.818
	Df	1/48	1/48	1/26	1/26	1/53	1/53	1/38	1/38
	P	<0.001	<0.001	0.015	<0.001	0.001	<0.001	<0.001	<0.001
“Time” (49 time points)	F	33.940	44.490	31.480	51.650	33.940	44.490	26.068	20.035
	Df	48/2,304	48/2,304	48/1,248	48/1,248	48/2,544	48/2,544	48/1,824	48/1,824
	P	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Interaction: “Strain” by “Time”	F	6.407	4.011	7.910	9.500	7.886	7.798	4.121	4.084
	Df	144/2,304	144/2,304	144/1,248	144/1,248	144/2,544	144/2,544	144/1,824	144/1,824
	P	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

Notes: The repeated measure “Time” includes 49 time points, and the independent factor “Strain” includes strains abbreviated as G10, G15, U28, and F30. Data on each of four experiments (DD in two seasons and LD20:4 at 20°C and 29°C) were analyzed separately. Activity Measure: Locomotor Activity per 30 min; Sleep Measure: Sleep duration per 30 min. F, Df, P: F-ratio, degree of freedom, and level of significance for the main effects and interaction.

Abbreviations: rANOVA, repeated measure ANOVA; DD, constant darkness.

Table 2 Results of two-way rANOVAs with repeated measure “Time” and independent factor “Temperature”

Factor	Measure	G10		G15		U28		F30
		Activity	Sleep	Activity	Sleep	Activity	Sleep	Activity	Sleep
“Temperature” (20°C vs 29°C)	F	0.206	0.002	0.453	3.811	9.097	4.175	2.289	6.319
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.655	0.967	0.507	0.063	0.006	0.053	0.143	0.019
“Time” (49 time points)	F	5.704	6.575	15.572	14.913	23.783	20.316	20.223	19.421
	Df	48/960	48/960	48/1,152	48/1,152	48/1,056	48/1,056	48/1,200	48/1,200
	P	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Interaction: “Temperature” by “Time”	F	1.278	2.361	11.785	8.799	3.918	5.122	9.081	16.153
	Df	48/960	48/960	48/1,152	48/1,152	48/1,056	48/1,056	48/1,200	48/1,200
	P	0.274	0.028	<0.001	<0.001	0.008	<0.001	<0.001	<0.001

Notes: The repeated measure “Time” (49 time points) and the independent factor “Temperature” (20°C and 29°C). Data on each of four stains in two long day experiments (20°C vs 29°C) were analyzed. Activity Measure: Locomotor Activity per 30 min; Sleep Measure: Sleep duration per 30 min. F, Df, P: F-ratio, degree of freedom, and level of significance for the main effects and interaction.

Abbreviation: rANOVA, repeated measure ANOVA.

Figure 4 Locomotor activity and sleep in four chronotypes under four experimental conditions. Data of each of four experiments under constant darkness (DD in summer and winter) and long photoperiod (LD20:4 at 20°C and at 29°C) were averaged within each of four strains (G10, U28, G15, and F30).

Notes: Summer, Winter, 20°C, and 29°C: Four experiments. Upper and lower graphs: Exposure to DD and LD20:4, respectively. Left and right graphs: Locomotor activity and sleep for summer and winter season in constant darkness (upper graphs) and for LD20:4 at 20°C and at 29°C (lower graphs), respectively. Black line on the x-axis indicates the interval of darkness, either 24 h for DD or 4 h on MN interval (between 23:00 and 3:00 of local clock time)
Abbreviations: SEM, standard error of mean; DD, constant darkness; EM, early morning (3:00–7:00); LM, late morning (7:00–11:00); MD, middle of the day (11:00–15:00); EE, early evening (15:00–19:00); LE, late evening (19:00–23:00); MN, middle of the night (23:00–3:00).

Table 3 Results of one-way MANOVAs with independent factor “Temperature”

Interval	Measure	G10		G15		U28		F30
		Activity	Sleep	Activity	Sleep	Activity	Sleep	Activity	Sleep
EM	F	1.401	3.496	3.796	9.291	10.561	8.074	5.861	9.599
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.250	0.076	0.063	0.006	0.004	0.009	0.023	0.005
LM	F	1.329	2.536	0.579	2.577	4.030	3.295	9.126	9.282
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.263	0.127	0.454	0.121	0.057	0.083	0.006	0.005
MD	F	0.189	1.460	3.390	6.092	0.336	0.051	30.399	49.613
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.668	0.241	0.078	0.021	0.568	0.824	<0.001	<0.001
EE	F	0.130	1.063	2.168	5.043	2.624	0.170	6.719	15.830
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.722	0.315	0.154	0.034	0.119	0.684	0.016	0.001
LM	F	0.735	0.638	1.579	3.758	6.830	1.075	1.713	0.418
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.401	0.434	0.221	0.064	0.016	0.311	0.202	0.524
MN	F	0.112	0.899	37.029	32.116	18.304	20.160	3.561	8.939
	Df	1/20	1/20	1/24	1/24	1/22	1/22	1/25	1/25
	P	0.742	0.354	<0.001	<0.001	<0.001	<0.001	0.071	0.006

Notes: The independent factor “Temperature” (20°C and 29°C). Data on each of four stains in 2 long day experiments (20°C vs 29°C) were analyzed. Activity Measure: Locomotor Activity per 30 min; Sleep Measure: Sleep duration per 30 min. F, Df, P: F-ratio, degree of freedom, and level of significance for the main effects. U28, the strain #28265 maintained in the Bloomington Drosophila Stock Center and collected in Raleigh, NC, USA; F30, the strain from P. Haddrill collected in Montpellier; G10 and G15, two strains from P. Haddrill collected in Ghana.

Abbreviations: DD, constant darkness; LD20:4, light–dark cycle consisting of 20 h of light and 4 h of darkness; EM, early morning (3:00–7:00); LM, late morning (7:00–11:00); MD, middle of the day (11:00–15:00); EE, early evening (15:00–19:00); LE, late evening (19:00–23:00); MN, middle of the night (23:00–3:00).