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1. The clock in growing hyphae and their synchronization in Neurospora crassa

   https://doi.org/10.1038/s42003-024-06429-6  

   Cheong, Jia_Hwei; Qiu, Xiao; Liu, Yang; Krach, Emily; Guo, Yinping; Bhusal, Shishir; Schüttler, Heinz-Bernd; Arnold, Jonathan; Mao, Leidong (June 2024, Communications Biology)

   Abstract Utilizing a microfluidic chip with serpentine channels, we inoculated the chip with an agar plug withNeurospora crassamycelium and successfully captured individual hyphae in channels. For the first time, we report the presence of an autonomous clock in hyphae. Fluorescence of a mCherry reporter gene driven by aclock-controlled gene-2 promoter(ccg-2p) was measured simultaneously along hyphae every half an hour for at least 6 days. We entrained single hyphae to light over a wide range of day lengths, including 6,12, 24, and 36 h days. Hyphae tracked in individual serpentine channels were highly synchronized (K = 0.60-0.78). Furthermore, hyphae also displayed temperature compensation properties, where the oscillation period was stable over a physiological range of temperatures from 24 °C to 30 °C (Q₁₀ = 1.00-1.10). A Clock Tube Model developed could mimic hyphal growth observed in the serpentine chip and provides a mechanism for the stable banding patterns seen in race tubes at the macroscopic scale and synchronization through molecules riding the growth wave in the device. 

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2. Membrane fluidity control by the Magnaporthe oryzae acyl-CoA binding protein sets the thermal range for host rice cell colonization

   https://doi.org/10.1371/journal.ppat.1012738  

   Richter, Michael; Segal, Lauren M; Rocha, Raquel O; Rokaya, Nisha; de_Queiroz, Aline R; Riekhof, Wayne R; Roston, Rebecca L; Wilson, Richard A (November 2024, PLOS Pathogens)

   Thomma, Bart PHJ (Ed.)

   Following leaf cuticle penetration by specialized appressorial cells, the devastating blast fungusMagnaporthe oryzaegrows as invasive hyphae (IH) in living rice cells. IH are separated from host cytoplasm by plant-derived membranes forming an apoplastic compartment and a punctate biotrophic interfacial complex (BIC) that mediate the molecular host-pathogen interaction. What molecular and cellular processes determine the temperature range for this biotrophic growth stage is an unanswered question pertinent to a broader understanding of how phytopathogens may cope with environmental stresses arising under climate change. Here, we shed light on thermal adaptation inM.oryzaeby disrupting theACB1gene encoding the single acyl-CoA-binding protein, an intracellular transporter of long-chain acyl-CoA esters. Loss ofACB1affected fatty acid desaturation levels and abolished pathogenicity at optimal (26°C) and low (22°C) but not elevated (29°C) infection temperatures (the latter following post-penetration shifts from 26°C). Relative to wild type, the Δacb1mutant strain exhibited poor vegetative growth and impaired membrane trafficking at 22°C and 26°C, but not at 29°C.In planta, Δacb1biotrophic growth was inhibited at 26°C–which was accompanied by a multi-BIC phenotype—but not at 29°C, where BIC formation was normal. Underpinning the Δacb1phenotype was impaired membrane fluidity at 22°C and 26°C but not at elevated temperatures, indicating Acb1 suppresses membrane rigidity at optimal- and suboptimal- but not supraoptimal temperatures. Deducing a temperature-dependent role for Acb1 in maintaining membrane fluidity homeostasis reveals how the thermal range for rice blast disease is both mechanistically determined and wider than hitherto appreciated. 

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3. A 120-330V, sub-μA, 4-Channel Driver for Microrobotic Actuators with Wireless-Optical Power Delivery and over 99% Current Efficiency

   https://doi.org/10.1109/VLSICircuits18222.2020.9162908  

   Rentmeister, J. S.; Pister, K.; Stauth, J. T. (July 2020, IEEE Symposium on VLSI Circuits (VLSI))

   This work presents a 4-channel, mm-scale, electrostatic and piezoelectric actuator driver that uses < 1μA total quiescent bias current and can drive actuator loads up to 120-330V at frequencies over 1kHz. The driver achieves over 99% current efficiency and can operate untethered with an integrated photovoltaic array driven by a collimated or diffuse optical power source. The circuit is tested with an off-chip boost circuit, generating over 1.5kV with 85% power efficiency at 45mW load. The system uses a simple 4-bit CMOS logic level interface with 100 kHz clock to actuate high voltage channels; on-chip photovoltaics also power the digital controller, and I/O bus. 

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4. A 120-330V, sub-µA, optically powered microrobotic drive IC for DARPA SHRIMP

   Rentmeister, J.S; Pister, K.; Stauth, J. T. (April 2020, GOMACTech 2020)

   This work presents a 4-channel, mm-scale, electro-static and piezoelectric actuator driver that uses< 1 µA total quiescent bias current and can drive actuator loads up to 120-330 V at frequencies over 1kHz. The driver achieves over 99% current efficiency and can operate untethered with an integrated photovoltaic array powered by a collimated or diffuse optical power source. The circuit is demonstrated also as a driver for an off-chip boost circuit, generating over 1.5 kV with 85% power efficiency at 45mW load. The system uses a simple 4-bit CMOS logic level interface with 100 kHz clock to actuate high voltage channels; on-chip photovoltaics also power the digital controller, and I/O bus. 

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5. Deletion of the Candida albicans TLO gene family using CRISPR-Cas9 mutagenesis allows characterisation of functional differences in α-, β- and γ- TLO gene function

   https://doi.org/10.1371/journal.pgen.1011082  

   Fletcher, Jessica; O’Connor-Moneley, James; Frawley, Dean; Flanagan, Peter R.; Alaalm, Leenah; Menendez-Manjon, Pilar; Estevez, Samuel Vega; Hendricks, Shane; Woodruff, Andrew L.; Buscaino, Alessia; et al (December 2023, PLOS Genetics)

   Forche, Anja (Ed.)

   TheCandida albicansgenome contains between ten and fifteen distinctTLOgenes that all encode a Med2 subunit of Mediator. In order to investigate the biological role of Med2/Tlo inC.albicanswe deleted all fourteenTLOgenes using CRISPR-Cas9 mutagenesis. ChIP-seq analysis showed that RNAP II localized to 55% fewer genes in thetloΔ mutant strain compared to the parent, while RNA-seq analysis showed that thetloΔ mutant exhibited differential expression of genes required for carbohydrate metabolism, stress responses, white-opaque switching and filamentous growth. Consequently, thetloΔ mutant grows poorly in glucose- and galactose-containing media, is unable to grow as true hyphae, is more sensitive to oxidative stress and is less virulent in the wax worm infection model. Reintegration of genes representative of the α-, β- and γ-TLOclades resulted in the complementation of the mutant phenotypes, but to different degrees.TLOα1could restore phenotypes and gene expression patterns similar to wild-type and was the strongest activator of glycolytic and Tye7-regulated gene expression. In contrast, the two γ-TLOgenes examined (i.e.,TLOγ5 and TLOγ11) had a far lower impact on complementing phenotypic and transcriptomic changes. Uniquely, expression ofTLOβ2in thetloΔmutant stimulated filamentous growth in YEPD medium and this phenotype was enhanced when Tloβ2 expression was increased to levels far in excess of Med3. In contrast, expression of reintegratedTLOgenes in atloΔ/med3Δdouble mutant background failed to restore any of the phenotypes tested, suggesting that complementation of these Tlo-regulated processes requires a functional Mediator tail module. Together, these data confirm the importance of Med2/Tlo in a wide range ofC.albicanscellular activities and demonstrate functional diversity within the gene family which may contribute to the success of this yeast as a coloniser and pathogen of humans. 

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