Biology subjects

Crawford, C. L.

Publications and source records attributed to Crawford, C. L..

4 recordsLinked to original sources

bioRxiv2025

Insights from U.S. beekeeper triage surveys following unusually high honey bee colony losses 2024-2025

In January of 2025, U.S. commercial beekeepers reported unusually high honey bee colony losses as they prepared colonies for almond pollination. Two industry groups launched nationwide surveys to document colony losses between June 2024 and March 2025 across all scales of beekeeping. This study analyzes these survey data to assess colony losses, estimate financial impacts, and identify correlations with beekeeper management practices and geographical locations. Unlike past surveys, commercial beekeepers experienced more severe losses than smaller-scale beekeepers during this period. Respondents, managing over half of U.S. colonies, most frequently cited Varroa mites as the cause for their losses. Varroa mites were followed by pesticides and pathogens in the case of commercial beekeepers and by queen failure and weather in the case of smaller-scale beekeepers. Although Varroa was the most frequently cited cause, losses did not significantly differ between users and non-users of amitraz, suggesting that rising amitraz resistance alone does not explain observed trends. Differences in protein and carbohydrate feeding frequencies also played a role in net losses. While colony loss rates and financial concern varied widely among respondents, commercial beekeepers understandably showed higher sensitivity to financial impacts, with concerns increasing linearly with loss severity. This study highlights the value of beekeeper surveys which, alongside direct analyses of bee samples and longitudinal studies, help identify effective management strategies and environmental risks. Such insights are crucial for addressing the leading causes of colony losses on a national scale, and ultimately aid in safeguarding honey bee health, pollination services, and agricultural production. HighlightsO_LIUnprecedented honey bee colony losses C_LIO_LIIndications of disease stress C_LIO_LIHigh economic pain for commercial beekeepers and growers C_LI

ecology↗

bioRxiv2025

Protocol for spatial characterization of ECM collagen-GAG in colorectal cancer tumor microenvironment

The extracellular matrix (ECM) plays a critical role in colorectal cancer (CRC) progression and therapeutic resistance. Accurate characterization of ECM composition and architecture is essential for understanding how CRC evades therapy, yet most protocols either assess ECM components in isolation or remain technically challenging. Here we present a robust yet simple protocol for spatial characterization of collagen and glycosaminoglycan (GAG) organization within the CRC tumor microenvironment (TME). Our method combines Alcian Blue and Picrosirius Red staining procedures with standardized tissue processing and imaging protocols. The protocol enables simultaneous visualization, assessment, and quantification of collagen and GAG distribution patterns in formalin-fixed, paraffin-embedded tissue sections. Key methodological advances include optimized dual-staining approach with distinct blue-red coloration for straightforward spectral separation on digital imaging systems, standardized reagent preparations, and validated imaging parameters. The complementary wavelengths facilitate both visual interpretation and potential digital separation, offering advantages over multi-component stains with overlapping spectral ranges. Validation across multiple CRC patient specimens demonstrates excellent reproducibility with consistent staining intensity using standard histology equipment. Because the resulting spatial maps can be compared directly with engineered or ex vivo tumor models, the protocol also provides a practical benchmark for microenvironment validation. This standardized approach to ECM visualization will advance TME research, support morphological studies, and enable comparative analyses across CRC subtypes. The methodology can be adapted to other solid tumor types and integrated with complementary techniques including digital pathology workflows for comprehensive microenvironment characterization and enhanced analysis capabilities.

pathology↗

bioRxiv2025

Potency and selectivity of a novel pan-RAS inhibitor in 3D bioprinted organoid tumor models

BackgroundColorectal cancer (CRC) remains a significant global health burden, with KRAS mutations driving [~]40% of cases. Efficacy of recently approved, mutant-specific KRAS inhibitors is limited by intrinsic and adaptive resistance mechanisms. Pan-RAS inhibitors, such as ADT-007, offer broader therapeutic potential by targeting multiple RAS isoforms. Here, we evaluate ADT-007 in 3D bioprinted organoid tumors (BOTs) generated from KRAS-mutant and RAS wild-type (WT) CRC cell lines. MethodsPotency and selectivity of ADT-007 were compared to bortezomib, a proteasome inhibitor, and YM155, a survivin inhibitor, using high-content imaging and ATP-based luminescence assays. Mechanistic studies assessed impact on RAS activation and downstream signaling. ResultsADT-007 exhibited high potency and selectivity in KRAS-mutant BOTs, reducing tumor burdens >30% at nanomolar concentrations, and demonstrated superior selectivity over bortezomib and YM155 with minimal cytotoxicity in RAS-WT BOTs. Mechanistic analysis confirmed ADT-007 inhibited RAS activation and downstream signaling, leading to selective apoptosis induction in KRAS-mutant CRC cells. ConclusionsThe selective potency and specificity of ADT-007 warrants further investigation of pan-RAS inhibitors for treating RAS-driven cancers. This study also underscores the translational utility of 3D BOT models for preclinical drug response assessment. Further validation in patient-derived BOTs is necessary to evaluate potential of ADT-007 in clinical settings.

bioengineering↗

bioRxiv2024

A myelinic channel system for organelle transport to the glial-axonal junction

Myelin sheaths comprise compacted layers of oligodendroglial membrane wrapped spirally around axons. Each sheath, if imagined unwrapped, has a cytoplasm-filled space at its perimeter, linking it to the oligodendrocyte soma via a short process. By electron microscopy (EM), this space, which we term the myelinic channel system contains microtubules and membranous organelles, but whether these are remnants of development or serve a function is unknown. Performing live imaging of myelinating oligodendrocytes expressing fluorescent reporters, we found that the myelinic channel system serves microtubule-dependent organelle transport. Further, the intra-myelinic movement of peroxisomes was modulated by neuronal electrical activity in these mixed neural cell cultures. Loss of oligodendroglial Kif21b or CNP in vivo led to apparent stasis of myelin organelles and secondary axon pathology. This suggests that oligodendrocytes require motor transport in myelin to maintain axonal integrity.

neuroscience↗