Rincheval, V. | Search bioRxiv

bioRxiv2026

Mating imperatives drive plasticity of the daily temporal niche via dopamine signaling.

Animals confine their daily activity to distinct diurnal, crepuscular, or nocturnal windows. It remains unclear how hundreds of sympatric species sharing the same temporal niche manage to coexist. To address this, we monitored the daily activity of the twilight-active, species-rich Drosophila genus under naturalistic conditions. Here, we show that intense sociosexual interactions rapidly drive a species-specific reformatting of their canonical crepuscular niche. The dominant sensory modality used for sexual communication predicts niche shift direction: reliance on chemosensation for courtship redirects behavioral activity into the night, while visual reliance shifts it into the day. This temporal plasticity bypasses the circadian clock, instead operating via a conserved dopaminergic pathway that simultaneously inhibits sleep and sustains sexual motivation. Our results reveal how mating imperatives enable conditional colonization of otherwise restricted temporal windows. Ultimately, by driving the divergence of previously overlapping niches, sociosexually induced temporal plasticity provides a powerful mechanism for sympatric coexistence in crowded environments.

neuroscience↗

bioRxiv2022

A corset of adhesions during development establishes individual neural stem cell niches and controls adult behaviour

Neural stem cells (NSCs) reside in a defined cellular microenvironment, the niche, which supports the generation and integration of neuronal lineages. The mechanisms building a sophisticated niche structure around NSCs, and their functional relevance for neurogenesis are yet to be understood. In the Drosophila larval brain, the cortex glia (CG) encase individual NSC lineages, organizing the stem cell population and newborn neurons into a stereotypic structure. We first found that lineage information is dominant over stem cell fate. We then discovered that, in addition to timing, the balance between multiple adhesion complexes supports the individual encasing of NSC lineages. An intra-lineage adhesion through homophilic Neuroglian interactions provides strong binding between cells of a same lineage, while a weaker interaction through Neurexin-IV exists between CG to NSC lineages. Their loss leads to random, aberrant grouping of several NSC lineages together, and to altered axonal projection of newborn neurons. Further, we link the loss of these two adhesion complexes during development to locomotor hyperactivity in the resulting adults. Altogether, our findings identify a corset of adhesions building a neurogenic niche at the scale of individual stem cell and provide the proof-of-principle that mechanisms supporting niche formation during development define adult behaviour.

developmental biology↗