Skip to main content
. Author manuscript; available in PMC: 2019 Jul 11.
Published in final edited form as: Science. 2019 Jan 11;363(6423):187–192. doi: 10.1126/science.aat4104

Fig. 2. Genetic complementation of Cry1 in SCN astrocytes initiates and sustains robust circadian patterns of locomotor activity in circadian incompetent Cry1/2-null mice.

Fig. 2

(A) Experimental design of in vivo expression of Flex-Cry1::EGFP restricted to SCN astrocytes or neurons by Syn- or GFAP-driven Cre, respectively. (B, C) Representative actograms and wavelet analyses of Cry1/2-null mice targeted with Cry1-Flex-Cry1::EGFP together with GFAP-EGFP (control) (B), or Cre expressing AAVs (C). Rhythmicity in LD1 and 2 is due to masking effect of the light-dark cycle. (D, E) Representative confocal tiled microphotographs of SCN sections from control and Cre-treated mice evaluated post-hoc to assess effective targeting of the SCN. Histograms represent co-localisation of fluorescence signals from mCherry::Cre and Cry1::EGFP in Cre-treated mice (insets). Total number of cells counted: GFAP-Cre: N(DAPI+)= 5491, n=5 targeted mice; Syn-Cre: N(DAPI+)= 6037, n=5 targetted mice. (F) Periods of circadian activity rhythms of control and Cre-treated mice before (DD1) and after (DD2) stereotaxic surgery. (G) Correlation analysis of number of Cry1::EGFP+ astrocytes or neurons and behavioral period (Syn-mCherry-Cre r=1 n=5, p= 0.02; GFAP-mCherry-Cre r=-0.70, n=10, p= 0.03, 2-way Spearman test). (H) Locomotor activity plotted across the circadian day (Mean±SEM). Group size is n(GFAP-EGFP)=7; n(GFAP-Cre)=10; nSyn-Cre)=5. Statistical test is 2-way RM-ANOVA, with a Bonferroni correction. **=p<0.01; ***=p<0.001. §§=p<0.01 Ad-hoc unpaired 2-tailed t-test with a Sidak-Bonferroni correction, Scale bars= 50 μm.