Biology subjects

Dalla Valle, L.

Publications and source records attributed to Dalla Valle, L..

3 recordsLinked to original sources

bioRxiv2026

Evolutionary co-option of the ancient protein AMBRA1 in plant photomorphogenesis

Photomorphogenesis, the light-driven developmental program of plants, is repressed in darkness by the CUL4-DDB1-COP1 ubiquitin ligase complex. In animals, AMBRA1 is a substrate receptor for the same CUL4-DDB1 machinery, regulating proteostasis, cell proliferation and autophagy, but its role in plants has remained unknown. Here we show that the moss Physcomitrium patens carries two light-regulated AMBRA1 genes, AMBRA1a and AMBRA1b, whose loss impairs vegetative growth and cell-fate transitions under light and prevents the elongation of gravitropic filaments in darkness, indicating that AMBRA1 is required to repress photomorphogenesis. AMBRA1 localizes to the nucleus under both long-day and dark conditions, and its loss causes widespread transcriptional reprogramming of developmental and metabolic pathways, including repression of photosynthesis-related genes in darkness. These findings identify AMBRA1 as a previously unrecognized nuclear regulator that links light availability to plant growth and as a key repressor of photomorphogenesis.

plant biology↗

bioRxiv2022

Ontogeny of learning and visual discrimination in zebrafish

With the exception of humans, early cognitive development has been thoroughly investigated only in precocial species, well developed at birth and with a broad behavioural and cognitive repertoire. We investigated another highly altricial species, the zebrafish, Danio rerio, whose embryonic development is very rapid: 72 hours. The nervous system of hatchlings is poorly developed, and their cognitive capacities are largely unknown. Larvae trained at 8 days post-fertilisation rapidly learned to associate a visual pattern with a food reward, showing significant performance at 10 days post-fertilisation. We exploited this capacity to study hatchlings discrimination learning capacities. Larval zebrafish rapidly and accurately learned colour and shape discriminations. They also discriminated a figure from its mirror image and from its 90{degrees}-rotated version, although with lower performance. Our study revealed impressive similarities in learning and visual discrimination capacities between newborn and adult zebrafish despite their enormous differences in brain size and degree of development.

animal behavior and cognition↗

bioRxiv2021

DOPAL initiates αSynuclein-mediated impaired proteostasis in neuronal projections leading to enhanced vulnerability in Parkinson's disease.

Dopamine dyshomeostasis has been acknowledged to be among the determinants of nigrostriatal neuron degeneration in Parkinsons disease (PD). Several studies in experimental models and postmortem PD patients underlined increasing levels of the aldehydic dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL), which is highly reactive towards proteins. DOPAL has been shown to covalently modify the presynaptic protein Synuclein (Syn), whose misfolding and aggregation represent a major trait of PD pathology, triggering Syn oligomerization in dopaminergic neurons. Here, we demonstrated that DOPAL elicits Syn neuronal accumulation and hampers Syn clearance at synapses and the soma. By combining cellular and in vivo models, we provided evidence that DOPAL-induced Syn buildup lessens neuronal resilience, compromises synaptic integrity, and overwhelms protein quality control pathways, specifically at neuronal projections. The resulting progressive decline of neuronal homeostasis leads to dopaminergic neuron loss and motor impairment, corroborating the Syn-DOPAL interplay as an early event in PD neurodegeneration.

neuroscience↗