Cyclic electron transfer (CET) predominates when NADP+ is at basal levels, early in photosynthetic induction; however, the mechanism underlying the subsequent supply of NADP+ to fully drive steady-state linear electron transfer remains unclear. Here, we investigated whether CET is involved in de novo NADP+ supply in Arabidopsis thaliana and measured chloroplastic NADP dynamics to evaluate responsiveness to variable light, photochemical inhibitors, darkness, and CET activity. The sum of oxidized and reduced forms shows that levels of NADP and NAD increase and decrease, respectively, in response to light; levels of NADP and NAD decrease and increase in the dark, respectively. Moreover, consistent with the pH change in the stroma, the pH preference of chloroplast NAD+ phosphorylation and NADP+ dephosphorylation is alkaline and weakly acidic, respectively. Furthermore, CET is correlated with upregulation of light-responsive NADP level increases and downregulation of dark-responsive NADP level reductions. These findings are consistent with CET helping to regulate NADP pool size via stromal pH regulation under fluctuating light conditions.

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of many cancer treatments. The hallmark of CIPN is degeneration of long axons required for transmission of sensory information; axonal degeneration causes impaired tactile sensation and persistent pain. Currently the molecular mechanisms of CIPN are not understood, and there are no available treatments. Here we show that the chemotherapeutic agent paclitaxel triggers CIPN by altering IP3 receptor phosphorylation and intracellular calcium flux, and activating calcium-dependent calpain proteases. Concomitantly paclitaxel impairs axonal trafficking of RNA-granules and reduces synthesis of Bclw (bcl2l2), a Bcl2 family member that binds IP3R1 and restrains axon degeneration. Surprisingly, Bclw or a stapled peptide corresponding to the Bclw BH4 domain interact with axonal IP3R1 and prevent paclitaxel-induced degeneration, while Bcl2 and BclxL cannot do so. Together these data identify a Bclw-IP3R1-dependent cascade that causes axon degeneration and suggest that Bclw-mimetics could provide effective therapy to prevent CIPN.

In mammals, sweet taste perception is mediated by the heterodimeric G-protein-coupled receptor, T1R2/T1R3. An interesting characteristic of this sweet taste receptor is that it has multiple ligand binding sites. Although there have been several studies on agonists of sweet taste receptors, little is known about antagonists of these receptors. In this study, we constructed a cell line stably expressing the human sweet taste receptor (hT1R2/hT1R3) and a functional chimeric G-protein (hG(alpha)16gust44) using the Flp-In system for measuring the antagonistic activity against the receptor. This constructed cell line responded quite intensely and frequently to the compounds applied for activation of hT1R2/hT1R3. In the presence of 3mM amiloride, the responses to sweet tastants such as sugar, artificial sweetener, and sweet protein were significantly reduced. The inhibitory activity of amiloride toward 1mM aspartame was observed in a dose-dependent manner with an IC(50) value of 0.87 mM. Our analysis of a cell line expressing hT1R3 mutants (hT1R3-A733V or hT1R3-F778A) made us to conclude that the target site of amiloride is distinct from that of lactisole, a known sweet taste inhibitor. Our results strongly indicate that amiloride reduces the sweet taste intensity by inhibiting the human sweet taste receptor and also that this receptor has multiple inhibitor binding sites.

Landscape genetics commonly focuses on the effects of environmental resistance on animal dispersal patterns, but there is an emerging focus on testing environmental effects on emigration and settlement choices. In this study, we used landscape genetics approaches to quantify dispersal patterns in the world's largest crocodilian, the saltwater crocodile (Crocodylus porosus), and demonstrated environmental influences on three processes that comprise dispersal: emigration, movement and settlement. We found that both environmental resistance and properties of the source and destination catchments (proportion of breeding habitat) were important factors influencing observed dispersal events. Our habitat quality variables related to hypotheses about resource competition and represented the ratio of breeding habitat (which limits carrying capacity), suggesting that competition for habitat influences emigration and settlement choices, together with the strong effect of environmental resistance to movement (where high-quality habitat was associated with greatest environmental permeability). Approximately 42% of crocodiles were migrants from populations other than their sampling locations and some outstandingly productive populations had a much higher proportion of emigration rather than immigration. The distance most commonly travelled between source and destination was 150-200 km although a few travelled much longer distances, up to 600-700 km. Given the extensive dispersal range, individual catchments or hydrographic regions that combine two or three adjacent catchments are an appropriate scale for population management.

Complex neural circuitry requires stable connections formed by lengthy axons. To maintain these functional circuits, fast transport delivers RNAs to distal axons where they undergo local translation. However, the mechanism that enables long-distance transport of RNA granules is not yet understood. Here, we demonstrate that a complex containing RNA and the RNA-binding protein (RBP) SFPQ interacts selectively with a tetrameric kinesin containing the adaptor KLC1 and the motor KIF5A. We show that the binding of SFPQ to the KIF5A/KLC1 motor complex is required for axon survival and is impacted by KIF5A mutations that cause Charcot-Marie Tooth (CMT) disease. Moreover, therapeutic approaches that bypass the need for local translation of SFPQ-bound proteins prevent axon degeneration in CMT models. Collectively, these observations indicate that KIF5A-mediated SFPQ-RNA granule transport may be a key function disrupted in KIF5A-linked neurologic diseases and that replacing axonally translated proteins serves as a therapeutic approach to axonal degenerative disorders.

This study aimed to evaluate the effects of swim-up and density gradient centrifugation methods on sperm DNA fragmentation.

The growth of tea plants (Camellia sinensis L.) is promoted by the presence of aluminum (Al), a beneficial element under acidic conditions, but the influence of rhizosphere pH on this interaction is not known. To understand the mechanisms underlying the adaptation to acidic rhizosphere conditions, we evaluated ionome profiles and the effect of pH on tea growth in hydroponic culture. The optimum pH for tea growth was around pH 4.2, and growth was inferior under a pH less than 3.8 or higher than 5.0. Under the optimum pH growth and Al accumulation were markedly stimulated by Al treatment. Al content and accumulation in new and mature leaves and new roots (the predominant tissues that accumulate minerals in tea plants) gradually declined with decrease in pH, especially in new roots. Ionome profiles drastically altered Al treatment, but changes were more pronounced in new roots than in new or mature leaves and did not depend on pH. Although the uptake of most cationic minerals in new roots was decreased by Al treatment, cationic mineral contents in new and mature leaves were not decreased by Al. In contrast to other plant species, the content and accumulation of manganese, despite it being a cationic nutrient, were significantly increased by Al treatment. These results indicated that one role of Al as a beneficial element was to maintain the shoot nutrient status by effectively utilizing Al-limited elements in the roots.

To function in diverse cellular processes, the dynamic properties of microtubules must be tightly regulated. Cellular microtubules are influenced by a multitude of regulatory proteins, but how their activities are spatiotemporally coordinated within the cell, or on specific microtubules, remains mostly obscure. The conserved kinesin-8 motor proteins are important microtubule regulators, and family members from diverse species combine directed motility with the ability to modify microtubule dynamics. Yet how kinesin-8 activities are appropriately deployed in the cellular context is largely unknown. Here we reveal the importance of the nonmotor tail in differentially controlling the physiological functions of the budding yeast kinesin-8, Kip3. We demonstrate that the tailless Kip3 motor domain adequately governs microtubule dynamics at the bud tip to allow spindle positioning in early mitosis. Notably, discrete regions of the tail mediate specific functions of Kip3 on astral and spindle microtubules. The region proximal to the motor domain operates to spatially regulate astral microtubule stability, while the distal tail serves a previously unrecognized role to control the timing of mitotic spindle disassembly. These findings provide insights into how nonmotor tail domains differentially control kinesin functions in cells and the mechanisms that spatiotemporally control the stability of cellular microtubules.

Hybrids between the critically endangered Siamese crocodile (Crocodylus siamensis) and least-concern saltwater crocodile (C. porosus) in captive populations represent a serious challenge for conservation and reintroduction programs due to the impact of anthropogenic activities. A previous study used microsatellite and mitochondrial DNA data to establish the criteria for identifying species and their hybrids; however, the results may have been influenced by biased allelic frequencies and genetic drift within the examined population. To overcome these limitations and identify the true signals of selection, alternative DNA markers and a diverse set of populations should be employed. Therefore, this study used DArT sequencing to identify genome-wide single nucleotide polymorphisms (SNPs) in both species and confirm the genetic scenario of the parental species and their hybrids. A population of saltwater crocodiles from Australia was used to compare the distribution of species-diagnostic SNPs. Different analytical approaches were compared to diagnose the level of hybridization when an admixture was present, wherein three individuals had potential backcrossing. Approximately 17.00-26.00% of loci were conserved between the Siamese and saltwater crocodile genomes. Species-diagnostic SNP loci for Siamese and saltwater crocodiles were identified as 8051 loci and 1288 loci, respectively. To validate the species-diagnostic SNP loci, a PCR-based approach was used by selecting 20 SNP loci for PCR primer design, among which 3 loci were successfully able to differentiate the actual species and different hybridization levels. Mitochondrial and nuclear genetic information, including microsatellite genotyping and species-diagnostic DNA markers, were combined as a novel method that can compensate for the limitations of each method. This method enables conservation prioritization before release into the wild, thereby ensuring sustainable genetic integrity for long-term species survival through reintroduction and management programs.