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Biology subjects

Pratt, B.

Publications and source records attributed to Pratt, B..

5 recordsLinked to original sources

3D multi-omic mapping of whole nondiseased human fallopian tubes at cellular resolution reveals a large incidence of ovarian cancer precursors

Uncovering the spatial and molecular landscape of precancerous lesions is essential for developing meaningful cancer prevention and early detection strategies. High-Grade Serous Carcinoma (HGSC), the most lethal gynecologic malignancy, often originates from Serous Tubal Intraepithelial Carcinomas (STICs) in the fallopian tubes, yet their minute size and our historical reliance on standard 2D histology contribute to their underreporting. Here, we present a spatially resolved, multi-omics framework that integrates whole-organ 3D imaging at cellular resolution with targeted proteomic, metabolomic, and transcriptomic profiling to detect and characterize microscopic tubal lesions. Using this platform, we identified a total of 99 STICs and their presumed precursors that harbor TP53 mutations in morphologically unremarkable tubal epithelium in all five specimens obtained from cancer-free organ donors with average-risk of developing ovarian cancer. Although these lesions comprised only 0.2% of the epithelial compartment, they displayed geographic diversity, immune exclusion, metabolic rewiring, and DNA copy number changes among lesions and normal fallopian tube epithelium discovered alterations in STIC-associated genes and the pathways they control. In sum, this platform provides a comprehensive 3D atlas of early neoplastic transformation, yielding mechanistic insights into tumor initiation and informing clinical screening strategies for detecting cancer precursors in whole organs at cellular resolution.

bioinformatics↗

Miniature linear and split-belt treadmills reveal mechanisms of adaptive motor control in walking Drosophila

To navigate complex environments, walking animals must detect and overcome unexpected perturbations. One technical challenge when investigating adaptive locomotion is measuring behavioral responses to precise perturbations during naturalistic walking; another is that manipulating neural activity in sensorimotor circuits often reduces spontaneous locomotion. To overcome these obstacles, we introduce miniature treadmill systems for coercing locomotion and tracking 3D kinematics of walking Drosophila. By systematically comparing walking in three experimental setups, we show that flies compelled to walk on the linear treadmill have similar stepping kinematics to freely walking flies, while kinematics of tethered walking flies are subtly different. Genetically silencing mechanosensory neurons alters step kinematics of flies walking on the linear treadmill across all speeds, while inter-leg coordination remains intact. We also found that flies can maintain a forward heading on a split-belt treadmill by adapting the step distance of their middle legs. Overall, these new insights demonstrate the utility of miniature treadmills for studying insect locomotion.

neuroscience↗

Snow flies self-amputate freezing limbs to sustain behavior at sub-zero temperatures

All living things are profoundly affected by temperature. In spite of the thermodynamic constraints on biology, some animals have evolved to live and move in extremely cold environments. Here, we investigate behavioral mechanisms of cold tolerance in the snow fly (Chionea spp.), a flightless crane fly that is active throughout the winter in boreal and alpine environments of the northern hemisphere. Using thermal imaging, we show that adult snow flies maintain the ability to walk down to an average body temperature of -7 {degrees}C. At this supercooling limit, ice crystallization occurs within the snow flys hemolymph and rapidly spreads throughout the body, resulting in death. However, we discovered that snow flies frequently survive freezing by rapidly amputating legs before ice crystallization can spread to their vital organs. Self-amputation of freezing limbs is a last-ditch tactic to prolong survival in frigid conditions that few animals can endure. Understanding the extreme physiology and behavior of snow insects is urgently important, as the alpine ecosystems they inhabit are being disproportionately altered by anthropogenic climate change.

animal behavior and cognition↗

The evolutionary trajectory of drosophilid walking

Neural circuits must both execute the behavioral repertoire of individuals and account for behavioral variation across species. Understanding how this variation emerges over evolutionary time requires large-scale phylogenetic comparisons of behavioral repertoires. Here, we describe the evolution of walking in fruit flies by capturing high-resolution, unconstrained movement from 13 species and 15 strains of drosophilids. We find that walking can be captured in a universal behavior space, the structure of which is evolutionarily conserved. However, the occurrence of, and transitions between, specific movements have evolved rapidly, resulting in repeated convergent evolution in the temporal structure of locomotion. Moreover, a meta-analysis demonstrates that many behaviors evolve more rapidly than other traits. Thus, the architecture and physiology of locomotor circuits can both execute precise individual movements in one species and simultaneously support rapid evolutionary changes in the temporal ordering of these modular elements across clades.

animal behavior and cognition↗

Tacc3 modulates microtubule network dynamicity and focal adhesion remodeling to affect cranial neural crest cell migration in Xenopus laevis

Coordinated cell migration is critical during embryogenesis, as cells must leave their point of origin, navigate a complex barrage of signals, and accurately position themselves to facilitate correct tissue and organ formation. The cell motility process relies on dynamic interactions of the F-actin and microtubule (MT) cytoskeletons. Our work focuses on how one MT plus-end regulator, Transforming Acidic Coiled-Coil 3 (Tacc3), can impact migration of cranial neural crest cells in Xenopus laevis. We previously demonstrated that tacc3 expression is expressed in cranial neural crest cells, and that Tacc3 can function as a MT plus-end tracking protein to regulate MT growth velocities. Here, we demonstrate that manipulation of Tacc3 protein levels is sufficient to alter cranial neural crest cell velocity in vitro. Tacc3 overexpression drives increased single-cell migration velocities, while Tacc3 KD results in reduced cell velocity and defective explant dispersion. We also show that Tacc3 can have spatially-enhanced effects on MT plus-end growth velocities as well as effects on focal adhesion remodeling. Together, we demonstrate that Tacc3 can facilitate neural crest cell motility through spatially-enhanced cytoskeletal remodeling, which may underlie the enhanced metastatic potential of Tacc3-overexpressing tumor cells.

cell biology↗