Anabaena circadian clock behavior under nitrogen-poor conditions from single-cell measurements of fluorescence intensity

Circadian clock arrays in multicellular filaments of the heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 display remarkable spatio-temporal coherence under nitrogen-replete conditions. To shed light on the interplay between circadian clocks and the formation of developmental patterns, we followed the expression of a clock-controlled gene under nitrogen deprivation, at the level of individual cells. Our experiments showed that differentiation into heterocysts took place preferentially within a limited interval of the circadian clock cycle, that gene expression in different vegetative intervals along a developed filament was discoordinated, and that the circadian clock was active in individual heterocysts. Furthermore, Anabaena mutants lacking the kaiABC genes encoding the circadian clock core components produced heterocysts but failed in diazotrophy. Therefore, genes related to some aspect of nitrogen fixation, rather than early or mid-heterocyst differentiation genes, are..., , , # Anabaena circadian clock behavior under nitrogen-poor conditions from single-cell measurements of fluorescence intensity

**Spatio-temporal coherence of circadian clocks and temporal control of differentiation in *Anabaena* filaments**

Rinat Arbel-Goren, Bareket Dassa, Anna Zhitnitsky, Ana Valladares, Antonia Herrero,

Enrique Flores and Joel Stavans

Deposited data includes the following data files used to generate different figures in the main text, with their respective description. Files of .opju type can be opened with OriginPro software (OriginLab Corporation).

**Noise and pecB expression in Anabaena filaments under nitrogen poor conditions.** Origin file containing the data of Figure S2 and the autofluorescence of photosynthetic pigments in Anabaena (AF) (column D). Column A represents time in minutes following nitrogen deprivation. Temporal dependence of noise (column left axis) of the expression intensity of PpecB-gfp for vegetative cells along a filament (column D) or wi...