Biology subjects

Chavez, F.

Publications and source records attributed to Chavez, F..

3 recordsLinked to original sources

bioRxiv2026

Marchantia polymorpha as a simple platform for plant-based production of functional nanobodies

Recombinant proteins have transformative potential in biomedicine, but their production is often costly and carries contamination risks. Plants offer an attractive alternative, with low growth costs and reduced pathogen risk, yet their slow growth cycles limit their use for rapid protein engineering. Here, we establish Marchantia polymorpha, a genetically tractable liverwort with a short life cycle, as a new platform for recombinant protein production. Using stable Agrobacterium-mediated transformation, we expressed an anti-mCherry nanobody fused to the fluorescent protein mTurquoise2 with different purification tags. Expression levels reached up to [~]120 {micro}g/g fresh weight, and nanobody functionality was validated through a microscopy-based bead-binding assay. This yield rivals that of established systems such as Nicotiana benthamiana. Our results position M. polymorpha as a scalable, safe, and efficient chassis for protein engineering, with broad potential for applications in synthetic biology. This work opens the door to exploiting liverwort biotechnology for fast, cost-effective, and biosafe production of valuable recombinant proteins. Graphical Table of Contents O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=133 SRC="FIGDIR/small/733889v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@aabc4aorg.highwire.dtl.DTLVardef@12f9fa4org.highwire.dtl.DTLVardef@199d3e0org.highwire.dtl.DTLVardef@2533a4_HPS_FORMAT_FIGEXP M_FIG C_FIG

Plant Biology↗

bioRxiv2026

Inorganic polyphosphate and pyoverdine synthesis are essential for the virulence of Pseudomonas aeruginosa PAO1 in zebrafish larvae

Understanding how bacterial metabolism shapes virulence requires infection models that are both biologically informative and experimentally accessible. Here, we used zebrafish (Danio rerio) larvae infection by static immersion as a simple and robust vertebrate model to study Pseudomonas aeruginosa host-pathogen interactions and virulence regulation. Using this approach, we show that disruption of polyphosphate (polyP) synthesis by loss of ppk1 gene ({tau}1ppk1) leads to marked attenuation of virulence, whereas interrupting ppk2 gene ({tau}1ppk2) results in a hypervirulent phenotype. Phenotypic assays and quantitative proteomics revealed that loss of polyP selectively impairs pyoverdine production, with minimal effects on other canonical virulence factors. Consistently, a pyoverdine-deficient mutant ({tau}1pvdF) exhibited reduced virulence in zebrafish, validating the capacity of the zebrafish model to functionally resolve key virulence factors. Together, our results highlight polyphosphate metabolism as a central regulator of P. aeruginosa virulence and position zebrafish immersion assays as an efficient and ethically aligned alternative to mammalian models for studying bacterial pathogenesis.

microbiology↗

bioRxiv2020

Toward Minimally Invasive Therapeutic Ultrasound: Ultrasound-guided Ablation in Neuro-oncology

IntroductionTo improve patient outcomes (eg, reducing blood loss and infection), practitioners have gravitated toward noninvasive and minimally invasive surgeries (MIS), which demand specialized toolkits. Focused ultrasound, for example, facilitates thermal ablation from a distance, thereby reducing injury to surrounding tissue. Focused ultrasound can often be performed noninvasively; however, it is more difficult to carry out in neuro-oncological tumors, as ultrasound is dramatically attenuated while propagating through the skull. This shortcoming has prompted exploration of MIS options for intracranial placement of focused ultrasound probes, such as within the BrainPath (NICO Corporation, Indianapolis, IN). Herein, we present the design, development, and in vitro testing of an image-guided, focused ultrasound prototype designed for use in MIS procedures. This probe can ablate neuro-oncological lesions despite its small size. Materials & MethodsPreliminary prototypes were iteratively designed, built, and tested. The final prototype consisted of three 8-mm-diameter therapeutic elements guided by an imaging probe. Probe functionality was validated on a series of tissue-mimicking phantoms. ResultsLesions were created in tissue-mimicking phantoms with average dimensions of 2.5x1.2x6.5mm and 3.4x3.25x9.36mm after 10- and 30-second sonification, respectively. 30s sonification with 118W power at 50% duty cycle generated a peak temperature of 68{degrees}C. Each ablation was visualized in real time by the built-in imaging probe. ConclusionWe developed and validated an ultrasound-guided focused ultrasound probe for use in MIS procedures. The dimensional constraints of the prototype were designed to reflect those of BrainPath trocars, which are MIS tools used to create atraumatic access to deep-seated brain pathologies. HIGHLIGHTSO_LIAn ultrasound-guided, focused ultrasound prototype was developed and validated C_LIO_LIThe therapeutic transducer (1.5MHz) consisted of three 8-mm circular elements C_LIO_LIElements were placed on a 9x32mm curved rectangular aperture: 45mm radius curvature C_LIO_LIFunctionality was examined on tissue-mimicking phantoms C_LIO_LI2.5x1.2x6.5mm and 3.4x3.25x9.36mm lesions were seen for 10 and 30s sonification C_LI

bioengineering↗