Biology subjects

Gonzalez, K.

Publications and source records attributed to Gonzalez, K..

8 recordsLinked to original sources

bioRxiv2026

Forest fragmentation, anthropogenic land use, and climate shape sand fly community composition in central Panama.

Background: American cutaneous leishmaniasis (ACL) is endemic in central Panama, where rapid land use change is transforming tropical landscapes and potentially altering the ecology of sand fly vectors. Although researchers have widely studied environmental determinants of individual vector species, community-level responses of sand fly assemblages to landscape modification remain poorly understood. We evaluated how landscape composition, fragmentation, climate, and topography influence sand fly community structure in a rural landscape of central Panama. Methodology/Principal Findings: We combined metacommunity analyses with joint species distribution models (JSDMs) to quantify species-specific and community-level responses to climatic variables, land-cover composition, and forest configuration. We collected 1,692 individuals representing 30 species, including nine anthropportunist taxa of epidemiological importance. Sand fly assemblages had strong nestedness, low species turnover, and predominantly positive residual associations. Several anthropportunist sand fly species occurred across heterogeneous landscapes, although their responses to environmental conditions differed among taxa. Land-cover composition, forest fragmentation metrics, and elevation together explained about half of the variance in species occurrence and abundance, with the remainder attributed to climate and spatial, temporal, and community-level random effects. Grassland cover contributed most strongly to sand fly occurrence and abundance, whereas artificial surfaces consistently reduced both metrics. Fragmentation effects varied by species: edge density often increased occurrence and abundance, whereas more forest patches generally suppressed populations. Increased precipitation broadly enhanced occurrence and abundance, whereas higher temperatures negatively affected several taxa. Conclusions/significance: Landscape heterogeneity predictably structures sand fly communities, and different forms of anthropogenic disturbance exert non-uniform effects on vector assemblages. The nested organization of these assemblages and the co-occurrence of several anthropophilic species suggest that multiple potential vector species may be present across heterogeneous landscapes. These findings highlight the need for landscape-informed surveillance and control strategies that prioritize grassland-forest interfaces and other disturbed ecotones where sand fly species of epidemiological importance frequently co-occur.

ecology↗

bioRxiv2026

Preclinical Evaluation of Chemoradiation Resistance Using 18F-FDG PET/CT in Head and Neck Squamous Cell Carcinoma

PurposeThere is an urgent need for improved prognostic tools and biological understanding of chemoradiation resistance in head and neck squamous cell carcinoma (HNSCC). This study established a preclinical imaging dataset aimed at identifying prognostic imaging features from 18F-FDG micro-PET/CT scans in HNSCC mouse models. MethodsThree orthotopic murine models were utilized: two human papillomavirus (HPV)-negative (MOC1, MOC2) and one HPV-positive (MLM1). When tumor volume exceeded 50 mm3, chemoradiation was initiated using cisplatin (5 mg/kg) and image-guided radiation therapy (8 Gy) on days 0 and 7. 18F-FDG micro-PET/CT imaging was performed on day 14. Tumors were manually segmented on PET/CT, and quantitative image features including tumor volume, SUVmean, and SUVmax were extracted. Treatment response was evaluated by relative tumor size on day 11 compared to day 0. Tumor growth and survival were compared across models using multiple-effects model and log-rank. Imaging feature associations were evaluated by Mann-Whitney U tests. Associations between survival, SUVmax, and tumor volume were assessed using Cox proportional hazards modeling and Kaplan-Meier analysis with log-rank testing. ResultsA total of 121 mice were treated and imaged. Significant differences in tumor growth and survival were observed among the three models (p < 0.01 for pairwise growth comparisons; p < 0.0001 for survival). Day 11 treatment response groups demonstrated significantly different growth trajectories following chemoradiation (p < 0.0001). SUVmax was significantly associated with survival (p = 0.0009), whereas SUVmean was not significant (p = 0.13). PET tumor volume demonstrated the strongest association with survival (p < 0.0001). A multivariate Cox proportional hazards model incorporating SUVmax and tumor volume significantly stratified survival risk (p < 0.0001). ConclusionOverall, these findings demonstrate that 18F-FDG PET/CT-derived metrics, particularly SUVmax and tumor volume, are robust predictors of chemoradiation response in orthotopic murine models of HNSCC.

cancer biology↗

bioRxiv2026

Mechanically-mediated low-pressure cell membrane poration enables tunable intracellular delivery of traditionally impermeable cargoes in high throughput and clinical scale formats

Traditional intracellular delivery methods suffer from cargo inefficiencies, non-linear delivery kinetics, and cellular trauma. We designed a mechanically-mediated poration platform governed by deterministic, passive diffusion operating at low pressure which enables dose-dependent, cargo-agnostic intracellular delivery and preserves cellular homeostasis; key advantages include high-fidelity multiplexing, transient cell engineering, and direct-to-biology live-cell target engagement enabling development of novel intracellular delivery applications across drug discovery and cell therapy. We demonstrate examples including live-cell DEL discovery and MOA studies, complex and rapid cell therapy manufacturing, and assay development in sensitive primary cell types.

cell biology↗

bioRxiv2026

A synthesis of the evidence for the acoustic space partitioning hypothesis

Acoustic interference is a critical factor driving the evolution of communication systems. In mixed-species choruses, competition for acoustic space is expected to drive signal differentiation among heterospecific signals. The acoustic space partitioning hypothesis proposes that species differentiate their signals to reduce overlap and thereby reduce acoustic interference. Despite ongoing debates in niche theory, studies in animal communication have remained disconnected from these conversations, and no critical evaluation of this hypothesis has been conducted. We performed a systematic review to assess empirical support for acoustic space partitioning and evaluate the conceptual and methodological approaches used to test it. We found that two-thirds of studies conclude that the acoustic space is partitioned, albeit with a strong taxonomic bias toward anurans. However, studies rarely account for key assumptions of the hypothesis, including co-signaling, limited acoustic space, and signal masking at the receiver. Without explicit evidence of conditions for acoustic interference, signal differentiation alone is insufficient to infer that competition is driving partitioning, since this outcome may also arise from alternative processes. By integrating sensory ecology, we provide a framework to reconcile signal-structure differentiation with receiver perception, thereby improving our understanding of how communication systems evolve in mixed-species choruses.

animal behavior and cognition↗

bioRxiv2026

Environmental DNA reveals hidden eukaryotic diversity and fine-scale community patterns across seascape areas in the Northern Red Sea

Understanding how reef-associated biodiversity responds to seascape features is essential for monitoring and conserving coral reef ecosystems. Environmental DNA (eDNA) from seawater provides access to benthopelagic eukaryotic diversity but its relationship with benthic structure remains poorly understood. We conducted simultaneous assessment of benthopelagic eDNA derived from near-reef seawater and benthic photoquadrat surveys across 12 coral reef sites in the northern Red Sea, spanning three seascape regions: the Gulf of Aqaba, nearshore Northern Red Sea (NRS), and offshore NRS. We examined whether spatial patterns in benthopelagic eDNA communities were structured across regions and whether variation in benthic cover explained differences in eDNA-derived assemblages obtained from water samples. Benthopelagic eDNA revealed fine-scale spatial structuring across regions but showed non-significant whole-community correlation with benthic composition. When examined by major taxonomic groups, taxon-specific relationships emerged, with some taxa (i.e., Micromonas sp.) showing increasing relative abundances in reefs characterized by lower benthic complexity. While traditional photoquadrat surveys captured 72 benthic sessile taxa including dominant benthic groups (e.g. hard corals and algae) across four eukaryotic phyla, benthopelagic eDNA documented a broader range of eukaryotic diversity, including planktonic, cryptic, and low abundant taxa spanning 35 phyla. Notably, eDNA detected cryptic organisms overlooked by visual surveys, such as the giant clam Tridacna sp., even where present but not recorded in photoquadrats. Our results demonstrate that benthopelagic eDNA and visual surveys provide complementary perspectives on reef biodiversity. Rather than serving as a direct proxy for benthic structure, benthopelagic eDNA captures spatial and taxonomic patterns that may be overlooked by visual transects, supporting its use in seascape-scale biodiversity assessments and conservation planning efforts in dynamic and understudied reef systems.

ecology↗

bioRxiv2025

Embryonic and larval development of Atelopus cruciger (Lichtenstein and Martens, 1856) (Anura: Bufonidae)

Harlequin toads (Atelopus) are one of the amphibian groups in greatest need of urgent conservation measures, Atelopus cruciger is one of the few species with known stable populations, yet basic natural history, including the embryonic and larval stages, remains largely unknown. We describe for the first time the development of its tadpole, from egg to tail resorption. The tadpole of Atelopus cruciger is gastromyzophorous with a general morphology resembling that for other congeneric species but with a distinct W-shaped whitish band that spans transversely across the midline of its dorsum. Development from egg to tail resorption takes between 110-147 days. In the wild, tadpoles live camouflaged beneath and alongside rocks in shallow sections of fast-flowing streams, with clear soft waters.

zoology↗

bioRxiv2024

A numbers game: Mosquito-based arbovirus surveillance in two distinct geographic regions of Latin America

Aedes mosquitoes, as vectors of medically important arthropod-borne viruses (arboviruses), constitute a major public health threat that requires entomological and epidemiological surveillance to guide vector control programs to prevent and reduce disease transmission. In this study, we present the collaborative effort of one year of mosquito-based arbovirus surveillance in two geographically distinct regions of Latin America (Nicaragua and Ecuador). Adult female mosquitoes were collected using backpack aspirators in over 2,800 randomly selected households (Nicaragua, Ecuador) and 100 key sites (Nicaragua) from eight distinct communities (Nicaragua: 2, Ecuador: 6). A total of 1,358 mosquito female pools were processed for RNA extraction and viral RNA detection using real-time RT-PCR. Ten positive dengue virus (DENV) pools were detected (3 in Nicaragua and 7 in Ecuador), all of which were found during the rainy season and matched the serotypes found in humans (Nicaragua: DENV-1 and DENV-4; Ecuador: DENV-2). Infection rates ranged from 1.13 to 23.13, with the Nicaraguan communities having the lowest infection rates. Our results demonstrate the feasibility of detecting DENV-infected Aedes mosquitoes in low-resource settings and underscore the need for targeted mosquito arbovirus sampling and testing, providing valuable insights for future surveillance programs in the Latin American region.

ecology↗

bioRxiv2021

PLB-985 neutrophil-like cells release antifungal extracellular vesicles against the human-pathogenic fungus Aspergillus fumigatus

Fungal infections remain a major global concern. Emerging fungal pathogens and increasing rates of resistance mean that additional research efforts and resources must be allocated to advancing our understanding of fungal pathogenesis and developing new therapeutic interventions. Neutrophilic granulocytes are a major cell type involved in protection against the important fungal pathogen Aspergillus fumigatus, where they employ numerous defense mechanisms, including production of antimicrobial extracellular vesicles. A major draw-back to work with neutrophils is the lack of a suitable cell line system for the study of fungal pathogenesis. To address this problem, we assessed the feasibility of using differentiated PLB-985 neutrophil-like cells as an in vitro model to study A. fumigatus infection. We find that dimethylformamide-differentiated PLB-985 cells provide a useful recapitulation of many aspects of A. fumigatus interactions with primary human polymorphonuclear leukocytes. We show that differentiated PLB-985 cells phagocytose fungal conidia and acidify conidia-containing phagolysosomes similar to primary neutrophils, release neutrophil extracellular traps, and also produce antifungal extracellular vesicles in response to infection. In addition, we provide an improved method for the isolation of extracellular vesicles produced during infection by employing a size-exclusion chromatography-based approach. Advanced LC-MS/MS proteomics revealed an enrichment of extracellular vesicle marker proteins and a decrease of cytoplasmic proteins in extracellular vesicles isolated using this improved method. Ultimately, we find that differentiated PLB-985 cells can serve as a genetically tractable model to study many aspects of A. fumigatus pathogenesis. IMPORTANCEPolymorphonuclear leukocytes are an important defense against human fungal pathogens, yet our model systems to study this group of cells remains very limited in scope. In this study, we established that differentiated PLB-985 cells can serve as a model to recapitulate several important aspects of human polymorphonuclear leukocyte interactions with the important human fungal pathogen Aspergillus fumigatus. The proposed addition of a cultured neutrophil-like cell line to the experimental toolbox to study fungal pathogenesis will allow for a more mechanistic description of neutrophil antifungal biology. In addition, the easier handling of the cell line compared to primary human neutrophils allowed us to use PLB-985 cells to provide an improved method for isolation of neutrophil-derived extracellular vesicles using size-exclusion chromatography. Together, these results provide significant tools and a baseline knowledge for the future study of neutrophil-derived extracellular vesicles in the laboratory.

microbiology↗