Biology subjects

Jones, J. A.

Publications and source records attributed to Jones, J. A..

At least 19 recordsLinked to original sources

bioRxiv2026

Cyclic immunofluorescence platform using photocleavable linkers for direct antibody labeling enables cancer phenotyping

Advances in spatial proteomics through the development of multiplexed immunostaining platforms have facilitated analyses with increasing cellular and molecular granularity. However, currently available approaches are limited by harsh conditions for signal removal, restricting the number of antigens that can be probed in a single specimen without significant alterations to sample quality and structure. Here we present an approach for direct labeling of primary antibodies with fluorophores using a photocleavable linker (PCL) with a polyethylene glycol spacer (PEG) to enable cyclic immunofluorescence (cyCIF) with gentle signal removal conditions. Our innovative approach uses directly labeled primary antibodies to enhance staining specificity and cyclic immunostaining efficiency, while minimizing nonspecific background signal. Additionally, through integration of the PCL, this approach facilitates gentle cleavage of antibody conjugated fluorophore, preserving sample integrity over multiple rounds of staining. Direct PEG-PCL antibody labeling will promote greater multiplexing by minimizing specimen damage and allow for quantitative analyses of cyCIF spatial data. We demonstrate that cyCIF with PEG-PCL conjugated antibodies can be applied across a variety of cancer subtypes to identify and characterize rare neoplastic cell populations in both tumor tissue and fragile peripheral blood specimens.

biochemistry↗

bioRxiv2026

Cell fusion reprograms tumor cells and promotes RUNX1-mediated invasion and dissemination in colorectal cancer

Metastasis remains the primary cause of cancer-related morbidity and mortality, despite significant advances in targeted therapies. Although metastatic dissemination requires tumor cells to escape the primary lesion and colonize distant organs, the mechanisms by which primary tumor cells gain metastatic competence remain poorly understood. Increasing evidence demonstrates that fusion of tumor (i.e., neoplastic) and immune (e.g., macrophages) cells generate a distinct population of tumor-immune hybrid cells with enhanced functional ability to migrate and disseminate into peripheral blood. Herein, our study investigates tumor-macrophage hybrid cells, an underexplored population of disseminated tumor cells, and their inherent heterogeneity and acquisition of molecular mechanisms underlying their dissemination as metastatic effectors in colorectal cancer (CRC). Through hybrid cell phenotyping utilizing integrative single-cell RNA sequencing (scRNA-seq), cyclic immunofluorescence (cyCIF) and functional assays with an in vitro model of CRC hybrid cells, we identify Runt-related transcription factor 1 (Runx1) as a central regulator of hybrid cell motility and invasion. Runx1 depletion in hybrid cells suppressed functional protease expression, chemotactic activity and extracellular matrix (ECM) invasion. Furthermore, pharmacologic inhibition of RUNX1 in an in vivo model reduced hybrid tumor growth and dissemination into peripheral blood, key attributes of metastatic spread of disease. In patients with CRC, RUNX1+ hybrid cells were identified in both primary tumor and peripheral blood, where circulating hybrid cells (CHCs) exhibited enriched migratory and epithelial-to-mesenchymal transition (EMT) phenotypes. Taken together, these findings reveal a mechanistic role for RUNX1 in driving invasive behavior of tumor-immune hybrids and highlight disseminated CHCs as an under-recognized contributor to metastatic spread and a promising noninvasive biomarker for tumor progression.

cancer biology↗

bioRxiv2026

A permeable protein nanocage enables facile cargo loading and cytosolic protein delivery

The cytosolic delivery of therapeutic proteins remains one of the most persistent challenges in modern drug delivery. Here, we report the discovery and characterization of an encapsulin-based protein nanocage, QtEnc, with unexpected permeability properties and the ability to internalize cargo proteins in vitro, fundamentally departing from existing protein nanocage cargo loading paradigms. This permeability enables simple, rapid, and single-step post-assembly cargo loading, accommodating cargos as large as 482 kDa, and allowing multiplexed cargo co-encapsulation with tunable ratios. Leveraging this property, we develop a modular QtEnc-based NanoCarrier (QtEncNC) with a pH-responsive cargo detachment module and an endosomal escape module, enabling low pH-triggered cargo release from assembled shells and subsequent endosomal escape for cytosolic delivery. Using a cytotoxic protein, BLF1, as a proof-of-concept QtEncNC payload, we demonstrate efficient cytosolic protein delivery in HeLa cells. These findings establish QtEncNC as a versatile and modular platform for cytosolic protein delivery with broad biomedical potential.

bioengineering↗

bioRxiv2025

The dung beetle microbiome complements host metabolism and nutrition

Many multicellular organisms rely on communities of microbial organisms to properly benefit from their diets, for instance by assisting in the breakdown of complex polysaccharides, the synthesis of essential resources, detoxification, or even preventing putrefaction. Dung beetles commonly rely on herbivore dung as their main source of nutrition, a diet rich in recalcitrant, hard-to-digest plant polysaccharides yet poor in essential amino acids, which animals typically cannot synthesize on their own. The work presented here investigates the potential role of the host-associated microbial community in allowing these insects to thrive on their nutrient-poor diet. Specifically, we investigated if the microbiota of the bull-headed dung beetle, Onthophagus taurus, may be capable of synthesizing amino acids and breaking down complex plant polysaccharides. To do so we functionally annotated genes within metagenomically assembled genomes (MAGs) obtained via shotgun-metagenomic sequencing. The annotation of these MAGs revealed that bacteria found in association with O. taurus possess the metabolic potential necessary to bridge the gap between host metabolic needs and the limitations imposed by their diet. Specifically, O. taurus microbiota contain amino acid biosynthesis pathways and genes encoding cellulases and xylanases, both of which are absent in the beetle genome. Further, multiple functionally relevant bacterial taxa identified here have also been observed in other studies across diverse dung beetle species, possibly suggesting a conserved pool of dung beetle symbionts and metabolic functions. ImportanceHost-symbiont interactions allow animals to take advantage of incomplete and/or challenging diets and niches. The work presented here aims to identify the physiological and metabolic means by which host associated microbial species shape the ecology of one of the most speciose genera in the animal kingdom: dung beetles in the genus Onthophagus. Both larva and adult stages of most Onthophagus rely on herbivore dung, a diet rich in recalcitrant, hard-to-digest plant polysaccharides yet poor in essential amino acids, which animals typically cannot synthesize on their own. To utilize such a challenging diet, Onthophagus vertically transmit a maternally derived microbial community which supports normative development in immature individuals and maintenance and reproduction in adults. Taken together, Onthophagus extraordinary diversity, complex ecology, and varied relationship with their microbial associates make them an ideal system to investigate mechanisms and diversification of host-diet-microbiome interactions.

microbiology↗

bioRxiv2025

Age- and estrous-dependent effects of psilocybin in rats

Psilocybin, a psychedelic compound in "magic" mushrooms, has promise as a novel treatment for psychiatric disorders, many of which are more prevalent in females and have onsets during adolescence. However, there is a lack of research about how factors such as sex and age affect responses to psilocybin, as well as potential safety concerns with developmental exposure. The primary objectives of this preclinical study were to determine if psilocybin-induced head twitch responses differ between adolescent and adult rats, and if estrous phase contributes to variation in female head twitch responses. Secondarily, this study sought to determine if treatment with psilocybin during adolescence has long-term effects on anxiety-associated behaviors and behavioral flexibility. Results showed that 1 mg/kg intraoral psilocybin failed to elicit head twitch responses in adolescents (P35 and P45) but elicited robust responses in adult rats. Further, adolescent psilocybin exposure did not cause long-term differences in performance on the elevated zero maze or probabilistic reversal learning tasks. Lastly, adult females in diestrus showed increased head twitch responses after 1 mg/kg psilocybin compared to females in proestrus. Head twitch responses are thought to be mediated by 5-HT2A receptors, but no age-or estrous-related differences in 5-HT2A receptor expression were observed in the medial prefrontal cortex. Collectively, these results highlight the existence of age-and sex-dependent differences in the effects of psychedelics, while finding no long-term effects on selected behaviors after adolescent exposure. These findings have implications on psychedelic study design, emphasizing the need for inclusive research considering age, sex, and hormonal status.

pharmacology and toxicology↗

bioRxiv2024

Development and early life stress sensitivity of the rat cortical microstructural similarity network

Understanding how early life experiences shape brain network development is a key challenge in the neuroscience of mental health disorders. To address this, we used magnetic resonance imaging (MRI) similarity network analysis to study the effects of stress in the rat, an important animal model in neuropsychiatry. We measured magnetization transfer ratio (MTR) at each of 53 distinct cortical areas and estimated a cortical similarity network for each individual scan, in two independent experimental datasets. We first characterized normative network development in rats scanned repeatedly between postnatal days 20 (weanling) and 290 (mid-adulthood) (N=47), and then contrasted these findings with a cohort exposed to early life stress in the form of repeated maternal separation (RMS, N=40). The normative rat cortical similarity network exhibited biologically meaningful organization, aligning with prior cytoarchitectonic and tract-tracing data, and displayed complex topological features, including rich club organization. During postnatal and adolescent development, brain regions became more similar, including an early phase of fronto-hippocampal convergence. Early increases in inter-areal similarity were reversed in a later phase of fronto-hippocampal divergence in mid-adulthood. RMS exposure altered inter-areal similarity, especially between frontal and parahippocampal regions, that were also most active developmentally and in aging. Our results reveal how normative cortical network changes in the developing brain are influenced by early life stress. These findings suggest a new translational framework for elucidating how environmental risk factors lead to atypical development of cortical networks.

neuroscience↗

bioRxiv2024

A high-performance genetically encoded sensor for cellular imaging of PKC activity in vivo

We report a genetically encoded fluorescence lifetime sensor for protein kinase C (PKC) activity, named CKAR3, based on Forster resonance energy transfer. CKAR3 exhibits a 10-fold increased dynamic range compared to its parental sensors and enables in vivo imaging of PKC activity during animal behavior. Our results reveal robust PKC activity in a sparse neuronal subset in the motor cortex during locomotion, in part mediated by muscarinic acetylcholine receptors.

neuroscience↗

bioRxiv2023

Analysis of uveal melanoma scRNA sequencing data identifies neoplastic-immune hybrid cells that exhibit metastatic potential

Uveal melanoma (UM) is the most common non-cutaneous melanoma and is an intraocular malignancy that affects nearly 7,000 individuals per year worldwide. Of these, nearly 50% will progress to metastatic disease for which there are currently no effective therapies. Despite advances in the molecular profiling and metastatic stratification of class 1 and 2 UM tumors, little is known regarding the underlying biology of UM metastasis. Our group has identified a disseminated tumor cell population characterized by co-expression of immune and melanoma proteins, (circulating hybrid cells (CHCs), in patients with UM. Compared to circulating tumor cells, CHCs are detected at an increased prevalence in peripheral blood and can be used as a non-invasive biomarker to predict metastatic progression. To identify mechanisms underlying enhanced hybrid cell dissemination we sought to identify hybrid cells within a primary UM single cell RNA-seq dataset. Using rigorous doublet discrimination approaches, we identified UM hybrids and evaluated their gene expression, predicted ligand-receptor status, and cell-cell communication state in relation to other melanoma and immune cells within the primary tumor. We identified several genes and pathways upregulated in hybrid cells, including those involved in enhancing cell motility and cytoskeleton rearrangement, evading immune detection, and altering cellular metabolism. In addition, we identified that hybrid cells express ligand-receptor signaling pathways implicated in promoting cancer metastasis including IGF1-IGFR1, GAS6-AXL, LGALS9-P4HB, APP-CD74 and CXCL12-CXCR4. These results contribute to our understanding of tumor progression and interactions between tumor cells and immune cells in the UM microenvironment that may promote metastasis.

cancer biology↗

bioRxiv2023

Pharmacological and behavioral effects of tryptamines present in psilocybin-containing mushrooms

Demand for more efficacious antidepressants, particularly those with a rapid onset of action, has resulted in a reevaluation of psychedelic drugs for their therapeutic potential. Several tryptamines found in psilocybin-containing magic mushrooms share chemical similarities with psilocybin, and early work suggests they may also share receptor targets. However, few studies have explored their pharmacological and behavioral effects. To accomplish this, we compared baeocystin, norbaeocystin, and aeruginascin with psilocybin to determine if they are metabolized by the same enzymes, penetrate the blood brain barrier, serve as ligands for similar centrally located receptors, and modulate behavior in rodents similarly. We first assessed the stability and optimal storage and handling conditions for each compound. In vitro enzyme kinetics assays then found that all compounds shared nearly identical rates of dephosphorylation via alkaline phosphatase and metabolism by monoamine oxidase. Further, we found that only the dephosphorylated products of baeocystin and norbaeocystin could cross a blood brain barrier mimetic to a similar degree as the dephosphorylated form of psilocybin, psilocin. Behaviorally, only psilocybin was found to induce head twitch responses in rats, a marker of 5HT2A agonism and indicator of the compounds hallucinogenic potential. However, like psilocybin, norbaeocystin was also found to improve outcomes in the forced swim test. All compounds were found to cause minimal changes to metrics of renal and hepatic health, suggesting innocuous safety profiles. Collectively, this work suggests that other naturally-occurring tryptamines, especially norbaeocystin, may share the same therapeutic potential as psilocybin, but without causing hallucinations. HIGHLIGHTSO_LIBaeocystin, norbaeocystin, and aeruginascin may have similar therapeutic value to psilocybin, but are understudied C_LIO_LICompound stability varied widely, with dephosphorylated forms showing lowest stability C_LIO_LIRates of metabolism by alkaline phosphatase and monoamine oxidase were similar across compounds C_LIO_LIBlood brain barrier penetration was limited to dephosphorylated forms of psilocybin, baeocystin, and norbaeocystin C_LIO_LIRat behavioral testing suggested norbaeocystin may have therapeutic utility similar to psilocybin, without causing hallucinations C_LI

pharmacology and toxicology↗

bioRxiv2023

Impacts of mate quality on female intrasexual aggression in two sister Malurus fairywren species

In a large and ever-growing number of animal species, it is now appreciated that females use colors as a visual signal in a range of social interactions, including both courtship and territorial aggression. Yet, it remains unclear whether female color phenotypes and/or aggressive behaviors are correlated with any attributes of their mates phenotype. For example, we might expect species in which males contribute more to parental care or territorial defense to have more colorful or aggressive females. On the other hand, within species, we might expect those females mated to higher quality males to be more colorful or aggressive than those mated to lower quality males. To begin to address these possibilities, we conducted a preliminary study in two sister taxa of fairywren (Maluridae) with distinct life-history strategies and plumage dichromatism: white-shouldered fairywrens (Malurus alboscapulatus moretoni) in tropical Papua New Guinea, a species in which both males and females have ornamented plumage and jointly defend territories year-round, and red-backed fairywrens (M. melanocephalus melanocephalus) in temperate Australia, a sexually dichromatic species with ornamented males and unornamented females. At the between species level, we predicted white-shouldered fairywren females would be more aggressive in same-sex interactions than red-backed fairywrens, as both white-shouldered males contribute to year-round territorial defense, whereas territories break-down during non-breeding in red-backed fairywrens. Further, we predicted that, within species, females mated to males of higher quality would be more aggressive in simulated same-sex encounters. Between species, female white-shouldered fairywrens were more aggressive on average than female red-backed fairywrens as predicted. Within both species, indices of male quality were not related to female aggression (although there was a non-significant tendency for more aggressive female white-shouldered fairywren to have heavier mates with longer tails). These results point to a need for additional research exploring relationships between life history, female plumage, and female aggressive behaviors in a wider range of species.

ecology↗

bioRxiv2023

Structural basis for peroxidase encapsulation in a protein nanocompartment

Encapsulins are self-assembling protein nanocompartments capable of selectively encapsulating dedicated cargo proteins, including enzymes involved in iron storage, sulfur metabolism, and stress resistance. They represent a unique compartmentalization strategy used by many pathogens to facilitate specialized metabolic capabilities. Encapsulation is mediated by specific cargo protein motifs known as targeting peptides (TPs), though the structural basis for encapsulation of the largest encapsulin cargo class, dye-decolorizing peroxidases (DyPs), is currently unknown. Here, we characterize a DyP-containing encapsulin from the enterobacterial pathogen Klebsiella pneumoniae. By combining cryo-electron microscopy with TP mutagenesis, we elucidate the molecular basis for cargo encapsulation. TP binding is mediated by cooperative hydrophobic and ionic interactions as well as shape complementarity. Our results expand the molecular understanding of enzyme encapsulation inside protein nanocompartments and lay the foundation for rationally modulating encapsulin cargo loading for biomedical and biotechnological applications.

biochemistry↗

bioRxiv2023

Role of Adenosine Deaminase in Prostate Cancer Progression

Prostate cancer (PCa) is the second most common cancer and constitutes about 14.7% of total cancer cases. PCa is highly prevalent and more aggressive in African American (AA) men when compared to European-American (EA) men. PCa tends to be a highly heterogeneous malignancy with a complex biology that is not fully understood. We use metabolomics as a tool to understand the mechanisms behind PCa progression and disparities in its clinical outcome. A key enzyme in the purine metabolic pathway, Adenosine deaminase (ADA) was found upregulated in PCa. ADA was also associated with higher-grade PCa and poor disease-free survival. The inosine-to-adenosine ratio which is a surrogate for ADA activity was high in the urine of PCa patients and higher in AA PCa compared to EA PCa. To understand the significance of high ADA in PCa, we established ADA overexpression models and performed various in vitro and in vivo studies. Our studies have revealed that an acute increase in the expression of ADA during later stages of tumor development enhances in vivo growth in multiple pre-clinical models. Further analysis reveals that this tumor growth could be driven by the activation of mTOR signaling. Chronic ADA overexpression shows alterations in the cells adhesion machinery and a decrease in the adhesion potential of the cells to the extracellular matrix in vitro. Loss of cell-matrix interaction is critical for metastatic dissemination, suggestive of ADAs role in promoting metastasis. This is consistent with the association of higher ADA expression with higher-grade tumors and poor patient survival. Overall, our findings suggest that increased ADA expression may promote PCa progression, specifically tumor growth and metastatic dissemination.

cancer biology↗

bioRxiv2023

Vascular Smooth Muscle Cell Mechanotransduction Through Serum and Glucocorticoid Inducible Kinase-1 Promotes Interleukin-6 Production and Macrophage Accumulation in Murine Hypertension

ObjectiveThe objective of this investigation was to demonstrate that in vivo induction of hypertension (HTN) and in vitro cyclic stretch of aortic VSMCs can cause SGK-1-dependent production of cytokines to promote macrophage accumulation as agents of vascular remodeling. MethodsHTN was induced in C57Bl/6 mice with AngiotensinII (AngII) infusion (1.46mg/kg/day x 21 days) with or without systemic infusion of EMD638683 (2.5mg/kg/day x 21 days), a selective SGK-1 inhibitor. Systolic blood pressure (SBP) was recorded on days 0 and 21. At terminal study, abdominal aortas were harvested to quantify SGK-1 activity (pSGK-1:SGK-1) by immunoblot. Additional replicates were digested and analyzed by flow cytometry for abundance of CD11b+/F4-80+ cells (macrophages). Plasma was analyzed by ELISA to quantify IL-6 and MCP-1. Aortic VSMCs from wild-type (WT) mice were subjected to 12% biaxial cyclic stretch for 3 or 12 hours +/- EMD638683 (10M) and +/- SGK-1siRNA with subsequent QPCR for IL-6 and MCP-1 expression. Culture media was analyzed by ELISA for IL-6 and MCP-1. Aortic VSMCs from SGK-1flox+/+ mice were transfected with Cre-Adenovirus to knockout SGK-1 (SGK-1KO VSMCs) and underwent parallel tension experimentation. Computational modeling was employed to simulate VSMC signaling due to mechanical strain and AngII. Statistical analysis included ANOVA with significance at p<0.05. ResultsSGK-1 activity (pSGK-1:SGK-1) was upregulated in the abdominal aorta of mice with HTN and significantly reduced by treatment with EMD638683. Concurrently, increased CD11b+/F4-80+ cells and plasma IL-6 levels in the HTN group and reduction with EMD638683 was observed. This mirrored the increased abundance of IL-6 in media from Stretch WT VSMCs, and attenuation of the effect with EMD638683. Treating WT VSMCs with SGK-1siRNA likewise inhibited IL-6 expression. MCP-1 also demonstrated increased expression and secretion into the media in WT VSMCs with Stretch. Further supporting the integral role of mechanical signaling through SGK-1, target gene expression and cytokine secretion was unchanged in SGK-1KO VSMCs with Stretch, and computer modeling confirmed SGK-1 as an intersecting node of signaling due to mechanical strain and AngII. In summation, this data suggests a biomechanical link between aortic VSMC mechanotransduction and cytokine production to promote macrophage accumulation, mediated in-part by SGK-1 activation. ConclusionMechanotransduction through SGK-1 is instrumental in pro-inflammatory cytokine production and aortic macrophage accumulation in systemic HTN, therefore further investigation into targeting this kinase may present opportunities to modulate hypertensive vascular remodeling.

physiology↗

bioRxiv2022

Exploring the Extreme Acid Tolerance of a Dynamic Protein Nanocage

Encapsulins are protein nanocages capable of efficient self-assembly and cargo enzyme encapsulation. They are found in a wide variety of bacteria and archaea, including many extremophiles, and are involved in iron and sulfur homeostasis, oxidative stress resistance, and secondary metabolite production. Resistance against physicochemical extremes like high temperature and low pH is a key adaptation of many extremophiles and also represents a highly desirable feature for many biotechnological applications. However, no systematic characterization of acid stable encapsulins has been carried out, while the influence of pH on encapsulin shells has so far not been thoroughly explored. Here, we report on a newly identified encapsulin nanocage (AaEnc) from the acid-tolerant bacterium Acidipropionibacterium acidipropionici. Using transmission electron microscopy, dynamic light scattering, and proteolytic assays, we demonstrate its extreme acid tolerance and resilience against proteases. We structurally characterize the novel nanocage using cryo-electron microscopy, revealing a dynamic five-fold pore that displays distinct "closed" and "open" states at neutral pH, but only a singular "closed" state under strongly acidic conditions. Further, the "open" state exhibits the largest pore in an encapsulin shell reported to date. Non-native protein encapsulation capabilities are demonstrated, and the influence of external pH on internalized cargo is explored. AaEnc is the first characterized highly acid stable encapsulin with a unique pH-dependent dynamic pore and its molecular characterization provides novel mechanistic details underlying the pH stability of large dynamic protein complexes.

biochemistry↗

bioRxiv2022

Human Cardiac Organoids to Model COVID-19 Cytokine Storm Induced Cardiac Injuries

Acute cardiac injuries occur in 20-25% of hospitalized COVID-19 patients. Despite urgent needs, there is a lack of 3D organotypic models of COVID-19 hearts for mechanistic studies and drug testing. Herein, we demonstrate that human cardiac organoids (hCOs) are a viable platform to model the cardiac injuries caused by COVID-19 hyperinflammation. As IL-1{beta}is an upstream cytokine and a core COVID-19 signature cytokine, it was used to stimulate hCOs to induce the release of a milieu of proinflammatory cytokines that mirror the profile of COVID-19 cytokine storm. The IL-1 {beta} treated hCOs recapitulated transcriptomic, structural, and functional signatures of COVID-19 hearts. The comparison of IL-1{beta} treated hCOs with cardiac tissue from COVID-19 autopsies illustrated the critical roles of hyper-inflammation in COVID-19 cardiac insults and indicated the cardioprotective effects of endothelium. The IL-1{beta} treated hCOs also provide a viable model to assess the efficacy and potential side effects of immunomodulatory drugs, as well as the reversibility of COVID-19 cardiac injuries at baseline and simulated exercise conditions.

bioengineering↗

bioRxiv2021

Lipid Alterations in African American Prostate Cancer

African-American (AA) men are more than twice as likely to die of prostate cancer (PCa) than European American (EA) men. Previous in-silico analysis revealed enrichment of altered lipid metabolic pathways in pan-cancer AA tumors. Here, we performed global unbiased lipidomics profiling on 48 matched localized PCa and benign adjacent tissues (30 AA, 24 ancestry-verified, and 18 EA, 8 ancestry verified) and quantified 429 lipids belonging to 15 lipid classes. Significant alterations in long chain polyunsaturated lipids was observed between PCa and benign adjacent tissues, low and high Gleason tumors, as well as associated with early biochemical recurrence, both in the entire cohort, and within AA patients. Altered levels of cholesteryl esters, and phosphatidyl inositols delineated AA and EA PCa, while levels of triglycerides, phosphatidyl glycerol, phosphatidyl choline, phosphatidic acid and cholesteryl esters distinguished AA and EA PCa patients with biochemical recurrence. These first-in-field results implicate lipid alterations as biological factors for prostate cancer disparities.

cancer biology↗

bioRxiv2021

Male White-shouldered Fairywrens (Malurus alboscapulatus) elevate testosterone when courting females but not during territorial challenges

Testosterone mediates suites of physical and behavioral traits across vertebrates, and circulation varies considerably across and within taxa. However, an understanding of the causal factors of variation in circulating testosterone has proven difficult despite decades of research. According to the challenge hypothesis, agonistic interactions between males immediately prior to the breeding season produce the highest levels of testosterone measured during this period. While many studies have provided support for this hypothesis, most species do not respond to male-male competition by elevating testosterone. As a result, a recent revision of the hypothesis ( challenge hypothesis 2.0) places male-female interactions as the primary cause of rapid elevations in testosterone circulation in male vertebrates. Here, we offer a test of both iterations of the challenge hypothesis in a tropical bird species. We first illustrate that male White-shouldered Fairywrens (Malurus alboscapulatus) differ by subspecies in plasma testosterone concentrations. Then we use a social network approach to find that males of the subspecies with higher testosterone are characterized by greater social interaction scores, including more time aggregating to perform sexual displays. Next, we use a controlled experiment to test whether males respond to simulated territorial intrusion or courtship interaction contexts by elevating testosterone. Males sampled during courtship had greater plasma testosterone both relative to flushed controls and males sampled during simulated intrusion. Ultimately, our results are consistent with challenge hypothesis 2.0, as males rapidly elevated testosterone following interactions with females, but not during territorial challenges.

animal behavior and cognition↗

bioRxiv2021

Triggered reversible disassembly of an engineered protein nanocage

Protein nanocages play crucial roles in sub-cellular compartmentalization and spatial control in all domains of life and have been used as biomolecular tools for applications in biocatalysis, drug delivery, and bionanotechnology. The ability to control their assembly state under physiological conditions would further expand their practical utility. To gain such control, we introduced a peptide capable of triggering conformational change at a key structural position in the largest known encapsulin nanocompartment. We report the structure of the resulting engineered nanocage and demonstrate its ability to on-demand disassemble and reassemble under physiological conditions. We demonstrate its capacity for in vivo encapsulation of proteins of choice while also demonstrating in vitro cargo loading capabilities. Our results represent a functionally robust addition to the nanocage toolbox and a novel approach for controlling protein nanocage disassembly and reassembly under mild conditions.

synthetic biology↗