Biology subjects

McKenna, B.

Publications and source records attributed to McKenna, B..

4 recordsLinked to original sources

bioRxiv2026

Response to geographic variation in song is associated with differential gene expression in the blood of a songbird

Birdsong mediates territory acquisition and mate choice. In agonistic interactions, local songs generally elicit stronger responses than songs from more distant populations. However, the molecular mechanisms associated with differential responses to local vs. foreign songs are poorly understood. We addressed this knowledge gap by combining behavioral assays in the field with blood transcriptomic analysis, using a within-subjects design to ask whether male song sparrows (Melospiza melodia) show differential gene expression when exposed to playback of local and foreign songs. Transcriptomic profiles reflected the difference in behavioral response to local vs. foreign songs, with individuals exposed to local songs showing greater expression of genes associated with song perception and production, anti-inflammatory responses and energy metabolism. Our study suggests that changes in expression of key molecular pathways correlate with behavioral responses to geographic song variation, providing insight into the potential mechanisms regulating signal recognition and response to social challenges. HighlightsO_LIGene expression in sparrow blood was measured after simulated territorial intrusion. C_LIO_LIStronger response to local songs was associated with differential gene expression. C_LIO_LISong-associated genes (FOXP2, NRXN1) had higher expression when birds heard local songs. C_LIO_LIGene expression in the blood contains potential biomarkers of song recognition. C_LI

molecular biology↗

bioRxiv2024

The antimicrobial potential of traditional remedies of Indigenous Peoples from Canada against MRSA planktonic and biofilm bacteria in wound-infection mimetic conditions

Methicillin-resistant Staphylococcus aureus (MRSA) is the leading cause of wound infections, often progressing into serious invasive bloodstream infections. MRSA disproportionately affects Indigenous peoples in Canada with higher rates of skin and wound infections, an example of persistent gaps in health outcomes between Indigenous and non-Indigenous peoples precipitated by the legacy of colonialism. Conversely, Indigenous peoples have long used natural remedies for infections and other diseases; however, their knowledge was rarely considered for modern medicine. The stagnant antibiotic discovery pipeline and alarming rise of resistance to current antibiotics prompted us to turn to Indigenous medicine as an untapped source of antimicrobials. As such, we collected and prepared 85 extracts of medicinal plants of value to Indigenous Peoples spanning the Canadian Prairies. We explored the antimicrobial potential of these extracts against MRSA under wound infection-mimetic conditions compared to culture media typically used to study bacterial antibiotic responses and biofilms but not adequately representative of infection sites. We identified extracts with MRSA growth inhibitory [e.g., bergamot, dock, gaillardia, and dandelion extracts] and biofilm prevention and eradication [e.g., gumweed extracts] activities. Extracts, including those of chokecherry, hoary puccoon, and Northern bedstraw, were only active under wound infection-mimetic conditions, highlighting the relevance of antibiotic discovery under host-relevant conditions. Testing growth inhibitory extracts against an S. aureus cross-resistance platform suggested that they act through mechanisms likely distinct from known antibiotic classes. Together, through an interdisciplinary partnership leveraging Western approaches and traditional Indigenous knowledge, we identified plant extracts with promising antimicrobial potential for drug-resistant MRSA wound infections.

microbiology↗

bioRxiv2017

Alleviation of Al toxicity by Si is associated with the formation of Al-Si complexes in root tissues of sorghum

Silicon is reported to reduce the toxic effects of Al on root elongation but the in planta mechanism by which this occurs remains unclear. Using seedlings of soybean (Glycine max) and sorghum (Sorghum bicolor), we examined the effect of up to 2 mM Si on root elongation rate (RER) in Al-toxic nutrient solutions. Synchrotron-based low energy X-ray fluorescence (LEXRF) was then used for the in situ examination of the distribution of Al and Si within cross-sections cut from the apical tissues of sorghum roots. The addition of Si potentially increased RER in Al-toxic solutions, with RER being up to ca. 0.3 mm h-1 (14 %) higher for soybean and ca. 0.2 mm h-1 (17 %) higher for sorghum relative to solutions without added Si. This improvement in RER could not be attributed to a change in Al-chemistry of the bulk nutrient solution, nor was it due to a change in the concentration of Al within the apical (0-10 mm) root tissues. Using LEXRF to examine sorghum, it was demonstrated that in roots exposed to both Al and Si, much of the Al was co-located with Si in the mucigel and outer apoplast. These observations suggest that Si reduces the toxicity of Al in planta through formation of Al-Si complexes in mucigel and outer cellular tissues, thereby decreasing the binding of Al to the cell wall where it is known to inhibit wall loosening as required for cell elongation.

plant biology↗

bioRxiv2017

Time-resolved analyses of elemental distribution and concentration in living plants: An example using manganese toxicity in cowpea leaves

O_LIKnowledge of elemental distribution and concentration within plant tissues is crucial in the understanding of almost every process that occurs within plants. However, analytical limitations have hindered the microscopic determination of changes over time in the location and concentration of nutrients and contaminants in living plant tissues.\nC_LIO_LIWe developed a novel method using synchrotron-based micro X-ray fluorescence (-XRF) that allows for laterally-resolved, multi-element, kinetic analyses of plant leaf tissues in vivo. To test the utility of this approach, we examined changes in the accumulation of Mn in unifoliate leaves of 7-d-old cowpea (Vigna unguiculata) plants grown for 48 h at 0.2 and 30 M Mn in solution.\nC_LIO_LIRepeated -XRF scanning did not damage leaf tissues demonstrating the validity of the method. Exposure to 30 M Mn for 48 h increased the initial number of small spots of localized high Mn and their concentration rose from 40 to 670 mg Mn kg-1 fresh mass. Extension of the two-dimensional -XRF scans to a three-dimensional geometry provided further assessment of Mn localization and concentration.\nC_LIO_LIThis method shows the value of synchrotron-based -XRF analyses for time-resolved in vivo analysis of elemental dynamics in plant sciences.\nC_LI

plant biology↗