Biology subjects

Bossi, F.

Publications and source records attributed to Bossi, F..

4 recordsLinked to original sources

bioRxiv2026

Longitudinal Characterization of a Novel Class of Recurrent, Stereotyped Neurophysiological Events in an Advanced Meditator

Seven EEG recordings over thirteen months revealed highly stereotyped transitions between distinct brain dynamics in an advanced meditator, providing a rare experimental window onto large-scale brain-state dynamics. We report an intensive longitudinal EEG case study of an experienced Tibetan tantric practitioner recorded across seven different measurement sessions, including concentrative and analytical meditation, three Dissolution of Elements sessions, nap, and reading sessions. Across conditions, the EEG repeatedly entered abrupt and reversible "ON" periods lasting tens of seconds. These periods were characterized by high-amplitude delta-theta activity, a structured 7-8 Hz component, fronto-central predominance, and a recurrent transient complex preceding state onset. Compared with matched pre- and post-event intervals, ON periods showed increased spectral power and directed connectivity, reduced relative variability, and high cross-session similarity, consistent with a recurrent and stereotyped macroscopic neurophysiological regime. Additional analyses did not support a straightforward explanation in terms of respiratory-rate changes, sleep-related variations, or overt movement artifacts. During Dissolution of Elements meditation event counts were consistent with the reported structure of the practice. However, given the current state of knowledge about the phenomenon, there is insufficient evidence to establish a close association with either the type of meditation session or the specific practices undertaken during the practitioners many years of retreat. We therefore distinguish the robust observation of a recurrent EEG regime from the more tentative hypothesis that it is related to advanced tantric meditative practice. What does appear to be well documented, however, is an unusual, abrupt, and reversible large-scale EEG reconfiguration in a deeply phenotyped expert volunteer, highlighting the value of intensive longitudinal single-participant designs for identifying and characterizing rare neurophysiological phenomena.

neuroscience↗

bioRxiv2021

Uncoupling differential water usage from drought resistance in a dwarf Arabidopsis mutant

Understanding the molecular and physiological mechanisms of how plants respond to drought is paramount to breeding more drought resistant crops. Certain mutations or allelic variations result in plants with altered water-use requirements. To correctly identify genetic differences which confer a drought phenotype, plants with different genotypes must be subjected to equal levels of drought stress. Many reports of advantageous mutations conferring drought resistance do not control for soil water content variations across genotypes and may therefore need to be re-examined. Here, we reassessed the drought phenotype of the Arabidopsis thaliana dwarf mutant, chiquita1-1 (also called costl), by growing mutant seedlings together with the wild type to ensure uniform soil water availability across genotypes. Our results demonstrate that the dwarf phenotype conferred by loss of CHIQ1 function results in constitutively lower water usage, but not increased drought resistance.

plant biology↗

bioRxiv2021

CHIQUITA1 maintains temporal transition between proliferation and differentiation in Arabidopsis thaliana

Body size varies widely among species, populations, and individuals depending on the environment. Transitioning between proliferation and differentiation is a crucial determinant of final organ size, but how the timing of this transition is established and maintained remains unknown. Using cell proliferation markers and genetic analysis, we show that CHIQUITA1 (CHIQ1) is required to maintain the timing of the transition from proliferation to differentiation in Arabidopsis thaliana. Combining kinematic and cell lineage tracking studies, we found that the number of actively dividing cells in chiquita1-1 plants decreases prematurely compared to wild type plants, suggesting CHIQ1 maintains the proliferative capacity in dividing cells and ensures that cells divide a certain number of times. CHIQ1 belongs to a plant-specific gene family of unknown molecular function and physically and genetically interacts with three close members of its family to control the timing of proliferation exit. Our work reveals the interdependency between cellular and organ-level processes underlying final organ size determination. SignificanceTiming of the transition between proliferation and differentiation is fundamental for determining the final size of organs and organisms. In agriculture, controlling organ and organism size can influence key agronomic traits such as yield and biomass. Dwarfism prevents lodging and was the trait responsible for the Green Revolution. Today, more sophisticated traits are needed for generating crops that are both resilient and sustainable. Revealing the molecular mechanisms that control the temporal transition between proliferation and differentiation will help unlock the potential of next-generation crops. Here, we report that CHIQUITA 1 in Arabidopsis thaliana is needed to maintain the proper timing of the transition between proliferation and differentiation in leaves and roots.

plant biology↗

bioRxiv2020

Hydration-dependent phase separation of a prion-like protein regulates seed germination during water stress.

Many organisms evolved strategies to survive and thrive under extreme desiccation. Plant seeds protect dehydrated embryos from a variety of stressors and can even lay dormant for millennia. While hydration is the key trigger that reactivates metabolism and kick-starts germination, the exact mechanism by which the embryo senses water remains unresolved. We identified an uncharacterized Arabidopsis thaliana prion-like protein we named FLOE1, which phase separates upon hydration and allows the embryo to sense water stress. We demonstrate that the biophysical states of FLOE1 condensates modulate its biological function in vivo in suppressing seed germination under unfavorable environments. We also find intragenic, intraspecific, and interspecific natural variations in phase separation propensity of FLOE1 homologs. These findings demonstrate a physiological role of phase separation in a multicellular organism and have direct implications for plant ecology and agriculture, especially the design of drought resistant crops, in the face of climate change.

cell biology↗