microPublication biology最新文献

Japanese hops are a closely related annual relative of the perennial crop species common hops, as such they are a potential genetic resource for accelerating hop breeding and cultivar development. Ploidy manipulation is an important tool in common hop breeding. In other crop systems, epidermal peels measuring guard cell traits-length, width, and plastid number-provide a rapid and low-cost method for screening ploidy levels. Guard cell length in Japanese hop exhibited intraindividual variability but appeared potentially less environmentally sensitive than plastid-based metrics in Japanese hop and trended higher in the tested triploid cultivar.

We successfully repeated an experiment where the anti-mitotic drug colcemid was fed to Drosophila larvae. Our aims were to (1) expand sample sizes, (2) improve survival at higher doses, (3) extend the treatment to adults, and (4) devise an improved method for assessing ploidy. We found that (1) colcemid has virtually no effect on germ cell ploidy in male larvae or female adults, (2) survival of larvae is increased by removing colcemid to allow metamorphosis, and (3) the wing margin offers a simple way to measure cell size, which is proportional to ploidy.

Plants synthesize compounds that interact with animal nervous systems to avoid predation, but the behavioral effects and underlying mechanisms of commonly encountered plant natural products remain understudied. We tested whether cannabis, ginger root, pepper tree, saffron, and tobacco extracts elicit chemotaxis responses in the nematode Caenorhabditis elegans . We found that tobacco extract repels C. elegans , whereas the other tested plant extracts did not have a significant effect on behavior. These experiments were conducted in an undergraduate laboratory course, providing both research training and new insights into plant-animal interactions.

Leaf litter decomposition rates vary widely in stream ecosystems and understanding how decay over time ( k ) varies by species can be critical to estimating allochthonous inputs and temporal changes in energy availability in streams. We deployed leaf packs of Japanese knotweed ( Reynoutria japonica ) and jewelweed ( Impatiens capensis ) with fine (0.5 mm) and coarse (3.35 mm) mesh to exclude or include macroinvertebrate shredders, respectively, over an 8-week period. We found jewelweed decomposed 3-7 times faster than knotweed and jewelweed in coarse packs decomposed faster than any published stream litter rate. These results highlight the importance of understanding context-dependent herbaceous species decomposition.

Lavandula angustifolia (lavender) extract displayed antioxidant properties in mammalian studies and has been promoted as a candidate neurotherapeutic for Alzheimer's disease (AD). To better inform its clinical utility, we exposed wildtype ( N2 ) and spr-4 mutant strains of C. elegans to extracts from this lavender species and examined animals for neurobehavioral changes in a mechanosensory phenotype. Importantly, spr-4 encodes the worm ortholog of repressor element 1-silencing transcription factor (REST), an established genetic modifier of AD. While low concentrations of lavender did not alter behavioral responses, spr-4 mutants selectively displayed neuronal vulnerability at the highest concentration tested, thereby revealing dose-responsive, lavender-associated neurotoxicity.

Isolated methylmalonic acidemia (MMA) is an autosomal recessive disorder that increases methylmalonic acid by affecting the metabolism of propionyl-CoA. Mutations in multiple genes cause MMA, however, those in methylmalonyl-CoA mutase ( MMUT ) are most common. MMUT is an isomerase that converts methylmalonyl-CoA to succinyl-CoA, a key tricarboxylic acid (TCA) cycle intermediate. The defects in these metabolic processes disproportionately affect hepatocytes in patients with MMA. We performed gene editing in human induced pluripotent stem cells (hiPSCs) to generate loss-of-function mutations within MMUT . Hepatocytes derived from these iPSCs recapitulate key aspects of methylmalonic acidemia, providing a new model of MMA.

C. elegans AGEF-1 , an ortholog of human ARFGEF1 and ARFGEF2, functions with ARF-1 , ARF-5 and the AP-1 clathrin adaptor to regulate membrane trafficking. Similar phenotypes induced by the agef-1 ( vh4 [E1028K]) allele and agef-1 (RNAi) suggested that agef-1 ( vh4 ) was a hypomorph. Here we report that agef-1 ( vh4 ) results in extrusion of yolk from the embryo. This is suppressed by RNAi of agef-1 , arf-1 , arf-5 but not AP-1. Based on structure of the yeast AGEF-1 ortholog, Sec7p, the E1028K change is predicted to activate AGEF-1 . Thus, Arf GTPase cycling is likely required to regulate trafficking with AP-1 but not with Arf effectors regulating yolk trafficking.

Zaprionus indianus , an invasive species of fruit fly originating from Africa, has successfully inhabited eastern North America but is thought to be seasonally limited by cold temperatures. We compared the cold acclimation abilities of Z. indianus to six drosophilid species. Each species' survival at -5°C was tested following acclimation periods at 10°C, 15°C, and 25°C. We found that Z. indianus had a similar baseline cold tolerance to other cosmopolitan species and acclimated following treatment at 15°C. Overall, cold acclimation in Z. indianus was better than tropical species but weaker than some cosmopolitan species, suggesting cold may restrict Z. indianus populations.

Nova53 is a novel bacteriophage with siphovirus morphology isolated from soil using Rhodococcus equi NRRL B-16538 as host. Nova53 has a genome of 137,941 base pairs that putatively encode 250 proteins and 31 tRNAs. Based on gene content, Nova53 is assigned to cluster CG that, to date, consists of only two other phages.

Many bacteria, and most archaea, have a paracrystalline protein surface layer (S-layer) encapsulating their outer membrane or cell wall. For pathogenic Rickettsia species, an S-layer has been hypothesized to be comprised of the outer membrane protein OmpB. We used cryo-electron tomography (cryoET) to image the Rickettsia parkeri cell surface and observed a repetitive S-layer structure proximal to the outer membrane of the bacterium that is absent in an ompB ^STOP ::tn mutant. Our data reveal that OmpB is essential for the Rickettsia S-layer and suggest that we can leverage cryoET to examine rickettsial S-layer structure and function.