Biology subjects

Pellegrino, K.

Publications and source records attributed to Pellegrino, K..

5 recordsLinked to original sources

bioRxiv2026

Postharvest tomato shelf life is genetically distinct from fruit firmness: evidence from two F2 populations

Reducing postharvest fruit loss without compromising fruit quality is a major goal in tomato breeding. Fruit shelf life is a complex trait, influenced by postharvest changes in fruit firmness and weight, as well as by both genetic and environmental factors. A QTL mapping experiment was conducted to identify loci associated with fruit shelf life-related traits using two distinct F2 tomato populations. Fruit weight, firmness, shelf life (evaluated as both loss of fruit weight and loss of firmness over time), and colour space components were measured, and QTLs were mapped using a commercial low-density SNP genotyping panel and bulk segregant sequencing analysis experiments. We show that fruit firmness at harvest is only weakly predictive of postharvest firmness loss, indicating that shelf life should be treated as a dynamic trait rather than a static firmness phenotype. Across the two populations, 60 QTLs defining 26 genomic regions were identified, including both population-specific loci and shared regions on chromosomes 9 and 12. Several narrow intervals contained candidate genes related to ethylene signaling, cell-wall remodeling, calcium transport, aquaporin-mediated water balance and stress responses. The identified QTLs and candidate genes are directly relevant to breeding programmes seeking to improve postharvest performance without using major ripening mutants that compromise fruit quality. Key messageComparative QTL mapping and BSA-Seq in two F2 tomato populations show that postharvest shelf life is only partly explained by fruit firmness at harvest and identify candidate loci for firmness loss and weight loss during storage.

plant biology↗

bioRxiv2025

Peripheral immune patterns enable robust cross-platform prediction of ALS onset and progression

Amyotrophic lateral sclerosis (ALS) progression rates vary dramatically between patients, yet the basis of this heterogeneity remains elusive, with no prognostic biomarkers existing to guide clinical decisions or stratify patients for therapeutic trials. Here, we identify a network of coordinated immune cell types, which exhibit differential disruption across progression groups. Using mass cytometry (CyTOF) to profile 2.2 million immune cells from 35 ALS patients stratified by progression rate and 9 healthy controls, we find that the extent of immune dysfunction cannot be reflected by examining differences in individual cell type frequencies. In contrast, analyses of correlation patterns between cell types revealed distinct immune organization patterns, where coordination complexity varied with disease progression. Across all progression groups, we observed striking immune reorganization in natural killer (NK) cells and a major shift from B cell/basophil coordination hubs in healthy controls to neutrophil/T cell-dominated patterns in ALS. Having established coordinated immune patterns, we developed machine learning models to further improve our ability to stratify between disease and non-disease cohorts, achieving superior performance compared to models using cell frequencies alone. Central and effector memory (CM/EM) CD4+ T cell interactions emerged as top discriminative features for disease status, while plasmacytoid dendritic cell (pDC) relationships, especially their ratio with regulatory T cells (T-regs), distinguished progression rates, supporting T-reg-based therapeutic approaches. These findings reframe ALS as a disease of immune coordination breakdown, pointing towards cell-type specific therapeutics and biomarkers that may extend beyond ALS to other neurodegenerative diseases characterized by immune dysfunction.

immunology↗

bioRxiv2025

Identification of a Thermogenic Target in the Dorsal Raphe Nucleus for Weight Management

Obesity emerges from a complex interplay of factors, including imbalanced interoception, genetic predisposition, and environmental cues, ultimately disrupting body weight homeostasis1. While much research has concentrated on strategies to suppress appetite for sustained weight loss, insufficient attention has been given to counterregulatory mechanisms that promote energy expenditure. Here, we show that chronic inhibition of GABAergic neurons in the Dorsal Raphe Nucleus (DRNVGAT) reduces body weight in diet-induced obese (DIO) mice. In this study, molecular profiling and in-situ hybridization in rodent and human brains revealed that the constitutively activated orphan receptor GPR6 is selectively enriched in DRNVGAT neurons. We next developed and administered a potent and highly selective GPR6 inverse agonist, which significantly reduced weight gain in DIO mice by stimulating brown adipose tissue thermogenesis without affecting appetite. Altogether, this study transitions from transcriptomic profiling, high-throughput drug screening and metabolic phenotyping to successfully identify a novel candidate to treat obesity.

neuroscience↗

bioRxiv2024

TDP-43 pathology links innate and adaptive immunity in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is the most common fatal motor neuron disease. Approximately 90% of ALS patients exhibit pathology of the master RNA regulator, Transactive Response DNA Binding protein (TDP-43). Despite the prevalence TDP-43 pathology in ALS motor neurons, recent findings suggest immune dysfunction is a determinant of disease progression in patients. Whether TDP-43 pathology elicits disease-modifying immune responses in ALS remains underexplored. In this study, we demonstrate that TDP-43 pathology is internalized by antigen presenting cells, causes vesicle rupture, and leads to innate and adaptive immune cell activation. Using a multiplex imaging platform, we observed interactions between innate and adaptive immune cells near TDP-43 pathological lesions in ALS brain. We used a mass cytometry-based whole-blood stimulation assay to provide evidence that ALS patient peripheral immune cells exhibit responses to TDP-43 aggregates. Taken together, this study provides a novel link between TDP-43 pathology and ALS immune dysfunction, and further highlights the translational and diagnostic implications of monitoring and manipulating the ALS immune response.

cell biology↗

bioRxiv2023

A Simple Subcortical Feeding Circuit Linking Interoceptive Inputs to Consummatory Behavior

The brain processes an array of stimuli enabling the selection of an appropriate behavioural response but the neural pathways linking interoceptive inputs to outputs for feeding are poorly understood. Here we delineate a subcortical circuit in which brain-derived neurotrophic factor (BDNF) expressing neurons in the ventromedial hypothalamus (VMH) directly connect interoceptive inputs to motor centers controlling food consumption and jaw movements. VMHBDNF neuron inhibition increases food intake by gating motor sequences of feeding through projections to premotor areas of the jaw. When food is unavailable, VMHBDNF inhibition elicits consummatory behaviors directed at inanimate objects such as a wooden block and inhibition of mesencephalic trigeminal area (Me5) projections evokes rhythmic jaw movements. The activity of these neurons is decreased during food consumption and increases when food is in proximity but not consumed. Activity is also increased in obese animals and after leptin treatment. VMHBDNF neurons receive monosynaptic inputs from both agouti-related peptide (AgRP) and proopiomelanocortin (POMC) neurons in the arcuate nucleus (Arc) and constitutive VMHBDNF activation blocks the orexigenic effect of AgRP activation. These data delineate an Arc[->]VMHBDNF[->]Me5 circuit that senses the energy state of an animal and regulates consummatory behaviors in a state dependent manner.

neuroscience↗