Optogenetic genome engineering tools enable spatiotemporal control of gene expression and provide new insight into biological function. Here, we report the new version of genetically encoded ...photoactivatable (PA) Cre recombinase, PA-Cre 3.0. To improve PA-Cre technology, we compare light-dimerization tools and optimize for mammalian expression using a CAG promoter, Magnets, and 2A self-cleaving peptide. To prevent background recombination caused by the high sequence similarity in the dimerization domains, we modify the codons for mouse gene targeting and viral production. Overall, these modifications significantly reduce dark leak activity and improve blue-light induction developing our new version, PA-Cre 3.0. As a resource, we have generated and validated AAV-PA-Cre 3.0 as well as two mouse lines that can conditionally express PA-Cre 3.0. Together these new tools will facilitate further biological and biomedical research.
Light-inducible systems allow spatiotemporal control of a variety of biological activities. Here, we report newly optimized optogenetic tools to induce transcription with light in mammalian cells, ...using the Arabidopsis photoreceptor Flavin Kelch-repeat F-box 1 (FKF1) and its binding partner GIGANTEA (GI) as well as CRY2/CIB1. By combining the mutagenesis of FKF1 with the optimization of a split FKF1/GI dimerized Gal4-VP16 transcriptional system, we identified constructs enabling significantly improved light-triggered transcriptional induction. In addition, we have improved the CRY2/CIB1-based light-inducible transcription with split construct optimization. The improvements regarding the FKF1/GI- and CRY2/CIB1-based systems will be widely applicable for the light-dependent control of transcription in mammalian cells.
A second-order phase transition is characterized by spontaneous symmetry breaking. The nature of the broken symmetry in the so-called "hidden-order" phase transition in the heavy-fermion compound ...URu(2)Si(2), at transition temperature T(h) = 17.5 K, has posed a long-standing mystery. We report the emergence of an in-plane anisotropy of the magnetic susceptibility below T(h), which breaks the four-fold rotational symmetry of the tetragonal URu(2)Si(2). Two-fold oscillations in the magnetic torque under in-plane field rotation were sensitively detected in small pure crystals. Our findings suggest that the hidden-order phase is an electronic "nematic" phase, a translationally invariant metallic phase with spontaneous breaking of rotational symmetry.
To clarify the cooperative roles of recurrently identified mutations and to establish a more precise risk classification system in acute myeloid leukemia (AML), we comprehensively analyzed mutations ...in 51 genes, as well as cytogenetics and 11 chimeric transcripts, in 197 adult patients with de novo AML who were registered in the Japan Adult Leukemia Study Group AML201 study. We identified a total of 505 mutations in 44 genes, while only five genes, FLT3, NPM1, CEBPA, DNMT3A and KIT, were mutated in more than 10% of the patients. Although several cooperative and exclusive mutation patterns were observed, the accumulated mutation number was higher in cytogenetically normal AML and lower in AML with RUNX1-RUNX1T1 and CBFB-MYH11, indicating a strong potential of these translocations for the initiation of AML. Furthermore, we evaluated the prognostic impacts of each sole mutation and the combinations of mutations and/or cytogenetics, and demonstrated that AML patients could be clearly stratified into five risk groups for overall survival by including the mutation status of DNMT3A, MLL-PTD and TP53 genes in the risk classification system of the European LeukemiaNet. These results indicate that the prognosis of AML could be stratified by the major mutation status in combination with cytogenetics.
Genomic selection (GS), which uses estimated genetic potential based on genome-wide genotype data for a breeding selection, is now widely accepted as an efficient method to improve genetically ...complex traits. We assessed the potential of GS for increasing soluble solids content and total fruit weight of tomato. A collection of big-fruited F
varieties was used to construct the GS models, and the progeny from crosses was used to validate the models. The present study includes two experiments: a prediction of a parental combination that generates superior progeny and the prediction of progeny phenotypes. The GS models successfully predicted a better parent even if the phenotypic value did not vary substantially between candidates. The GS models also predicted phenotypes of progeny, although their efficiency varied depending on the parental cross combinations and the selected traits. Although further analyses are required to apply GS in an actual breeding situation, our results indicated that GS is a promising strategy for future tomato breeding design.
To determine whether adolescents will modify their ordering behavior if calorie and fat nutrition information is posted on the restaurant menu.
Adolescent volunteers (aged 11 to 18 years) were asked ...to order a dinner of their choice from three different restaurant menus (McDonald’s, Panda Express, and Denny’s) and then from a second set of modified menus with calorie and fat content information posted next to each menu item. Total reported consumed calories, fat, and the price of the meal ordered were calculated for each meal.
For the first 106 adolescents enrolled, 75 did not change any of their orders after being shown the calorie and fat content information. For the 31 who did change some of their orders, 43 meals resulted in decreased calories and 11 meals resulted in increased calories (20 resulted in a more expensive meal, 23 resulted in a less expensive meal and 11 resulted in no change in the cost of the meal; average change $0.027 increase). Of the 27 who rated themselves as too fat or slightly overweight, only 9 (33%) changed their orders.
The provision of calorie and fat content information on the menus did not modify the food ordering behavior for the majority of adolescents. However, the provision of the nutrition information should still be encouraged because it resulted in some calorie/fat reduction by some of the adolescents and it did not adversely affect the restaurants’ revenue.
The field-orientation dependent thermal conductivity of the heavy-fermion superconductor UPt3 was measured down to very low temperatures and under magnetic fields throughout the distinct ...superconducting phases: B and C phases. In the C phase, a striking twofold oscillation of the thermal conductivity within the basal plane is resolved reflecting the superconducting gap structure with a line of node along the a axis. Moreover, we find an abrupt vanishing of the oscillation across a transition to the B phase, as a clear indication of a change of gap symmetries. We also identify extra two line nodes below and above the equator in both B and C phases. From these results together with the symmetry consideration, the gap function of UPt3 is determined as a E(1u) representation characterized by a combination of two line nodes at the tropics and point nodes at the poles.
The superconducting fluctuation effect, due to preformed Cooper pairs above the critical temperature Tc, has been generally understood by the standard Gaussian fluctuation theories in most ...superconductors1. The transverse thermoelectric (Nernst) effect is particularly sensitive to the fluctuations, and the large Nernst signal found in the pseudogap regime of the underdoped cuprates2, 3 has raised much debate. Here we report on the observation of a colossal Nernst signal due to the superconducting fluctuations in the heavy-fermion superconductor URu2Si2. The Nernst coefficient is anomalously enhanced (by a factor of ~106) as compared with the theoretically expected value of the Gaussian fluctuations. Moreover, contrary to the conventional wisdom, the enhancement is more significant with a reduction of the impurity scattering rate. This unconventional Nernst effect intimately reflects the highly unusual superconducting state of URu2Si2. The results invoke possible chiral or Berry-phase fluctuations associated with the broken time-reversal symmetry4, 5, 6, 7 of the superconducting order parameter.
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