Allatostatin C/AstC-R2 is a Novel Pathway to Modulate Circadian Activity Pattern in Drosophila

Six neuropeptides are expressed within the Drosophila brain circadian network. Our previous mRNA profiling suggested that AllatostatinC is a seventh neuropeptide and specifically expressed in dorsal clock neurons (DN1s). Our results here show that AstC is indeed expressed in DN1s, where it oscillates. AstC is also expressed in two less well-characterized circadian neuronal clusters, the DN3s and lateral posterior neurons (LPNs). Behavioral experiments indicate that clock neuron-derived AstC is required to mediate evening locomotor activity under short (winter-like) photoperiods. The AstC-Receptor 2 (AstC-R2) is expressed in LNds, the clock neurons that drive evening locomotor activity, and AstC-R2 is required in these neurons to modulate the same short photoperiod evening phenotype. Ex vivo calcium imaging indicates that AstC directly inhibits a single LNd neuron. The results suggest that a novel AstC/AstC-R2 signaling pathway, from dorsal circadian neurons to an LNd, regulates the behavioral response to changing photoperiod in Drosophila.

Habitat use and circadian pattern of Solitary TinamouTinamus solitariusin a southern Brazilian Atlantic rainforest

SummarySolitary TinamouTinamus solitariusis a threatened Brazilian bird, and very little is known about its ecology and behaviour. In this study we aimed to verify the use of habitats in different stages of plant succession and the circadian activity pattern of the species. The study was conducted in Santa Catarina state (27º43’S, 48º49’W). Six camera traps were used to record the species in three areas of different successional stages during a 12-month period. Traps remained at each sample site for two months, after which they were moved to a new site, a minimum distance of 100 m apart. A total of 76 independent records of Solitary Tinamou were obtained, and its habitat use was found to be different within the three successional stages (P= 0.02). The majority of 54 independent records were obtained in the secondary forest; not one photo of the species was taken in the most degraded area. Solitary Tinamou exhibited a crepuscular pattern of activity, with most records (n= 38) taken at 07h00 and 06h00, and it appears to be sensitive to forest clearance.