Biology subjects

Castaneda, A. N.

Publications and source records attributed to Castaneda, A. N..

3 recordsLinked to original sources

bioRxiv2021

Responses to Temperatures of Different Drosophila Species

Temperature is a critical environmental variable that affects the distribution, survival, and reproduction of most animals. Although temperature receptors have been identified in different animals, how these receptors respond to temperatures is largely unknown. Here we use modified single-fly thermotactic assays to analyze movements and temperature preferences of nine Drosophila species. The ability/inclination to move varies among these species and at different temperatures. Importantly, different species prefer various ranges of temperatures. While wild-type D. melanogaster flies avoid the warm temperature in the warm avoidance assay and the cool temperature in the cool avoidance assay, D. bipectinata and D. yakuba avoid neither warm nor cool temperatures and D. biarmipes and D. mojavensis do not avoid the warm temperature in the warm avoidance assay. These results demonstrate that Drosophila species have different mobilities and temperature preferences, thereby benefiting the research on molecular mechanisms of temperature responsiveness. Summary statementThe ability to move and the preference for temperatures vary among fly species when flies are exposed to steep temperature gradients.

animal behavior and cognition↗

bioRxiv2021

Using TrackMate to Analyze Drosophila Larval and Adult Locomotion

Drosophila adult and larvae exhibit sophisticated behaviors that are widely used in development, synaptic transmission, sensory physiology, and learning and memory research. Many of these behaviors depend on locomotion, the ability of an animal to move. However, the statistical analysis of locomotion is not trivial. Here we use an open-source Fiji plugin TrackMate to track the locomotion of Drosophila adults and larvae. We build optimal experimental setups to rapidly process recordings by Fiji and analyze by TrackMate. We also provide tips for analyzing non-optimal recordings. TrackMate extracts the X and Y positions of an animal on each frame of an image sequence or a video. This information allows for generating moving trajectories, calculating moving distances, and determining preference indices in two-choice assays. Notably, this free-cost analysis method does not require programming skills. Summary statementThis study uses an open-source Fiji plugin TrackMate to computationally analyze Drosophila adult and larval behavioral assays, which does not require programming skills.

animal behavior and cognition↗

bioRxiv2020

Natural Antisense Transcript of Period2, Per2AS, regulates the amplitude of the mouse circadian clock

Circadian transcriptome studies identified a novel transcript at the Period2 (Per2) locus, which we named Per2AS. Per2AS is a long non-coding RNA transcribed from the antisense strand of Per2, and is expressed rhythmically and anti-phasic to Per2 mRNA. Previously, we mathematically tested the hypothesis that Per2AS and Per2 mutually inhibit each others expression by forming a double negative feedback loop, and found that Per2AS expands the oscillatory domain. In this study, we have experimentally tested this prediction by perturbing the expression of Per2AS in mouse fibroblasts. We found that Per2AS represses Per2 pre-transcriptionally in cis and regulates the amplitude of the circadian clock, but not period or phase. Unexpectedly, we also found that Per2 positively regulates Per2AS post-transcriptionally, indicating that Per2AS and Per2 form a single negative feedback loop. Because knock-down of Per2 does not recapitulate the phenotypes of Per2AS perturbation and Per2AS also activates Bmal1 in trans, we propose that Per2AS regulates the amplitude of the circadian clock without producing a protein by rewiring the molecular clock circuit.

molecular biology↗