Studying the genetic signatures of climate-driven selection can produce insights into local adaptation and the potential impacts of climate change on populations. The honey bee (Apis mellifera) is an interesting species to study local adaptation because it originated in tropical/subtropical climatic regions and subsequently spread into temperate regions. However, little is known about the genetic basis of its adaptation to temperate climates. Here, we resequenced the whole genomes of ten individual bees from a newly discovered population in temperate China and downloaded resequenced data from 35 individuals from other populations. We found that the new population is an undescribed subspecies in the M-lineage of A. mellifera (Apis mellifera sinisxinyuan). Analyses of population history show that long-term global temperature has strongly influenced the demographic history of A. m. sinisxinyuan and its divergence from other subspecies. Further analyses comparing temperate and tropical populations identified several candidate genes related to fat body and the Hippo signaling pathway that are potentially involved in adaptation to temperate climates. Our results provide insights into the demographic history of the newly discovered A. m. sinisxinyuan, as well as the genetic basis of adaptation of A. mellifera to temperate climates at the genomic level. These findings will facilitate the selective breeding of A. mellifera to improve the survival of overwintering colonies.
A new type of hollow nanostructure featured double metal-organic frameworks shells with metal nanoparticles (MNPs) is designed and fabricated by the methods of ship in a bottle and bottle around the ship. The nanostructure material, hereinafter denoted as Void@HKUST-1/Pd@ZIF-8, is confirmed by the analyses of photograph, transmission electron microscopy, scanning electron microscopy, powder X-ray diffraction, inductively coupled plasma, and N sorption. It possesses various multifunctionally structural characteristics such as hollow cavity which can improve mass transfer, the adjacent of the inner HKUST-1 shell to the void which enables the matrix of the shell to host and well disperse MNPs, and an outer ZIF-8 shell which acts as protective layer against the leaching of MNPs and a sieve to guarantee molecular-size selectivity. This makes the material eligible candidates for the heterogeneous catalyst. As a proof of concept, the liquid-phase hydrogenation of olefins with different molecular sizes as a model reaction is employed. It demonstrates the efficient catalytic activity and size-selectivity of Void@HKUST-1/Pd@ZIF-8.
It is well established that 14-3-3 proteins are key regulators of multiple stress signal transduction cascades. However, the biological functions of soybean 14-3-3 proteins, especially in plant drought response, are not yet known. In this study, we characterized a Glycine soja 14-3-3 gene, GsGF14o, which is involved in plant development and drought response. GsGF14o expression was greatly induced by drought stress, as evidenced by the quantitative real-time PCR and β-glucuronidase (GUS) activity analysis. GsGF14o overexpression in Arabidopsis thaliana resulted in decreased drought tolerance during seed germination and seedling growth. Furthermore, silencing of AtGF14µ, the most homologous 14-3-3 gene of GsGF14o, led to enhanced drought tolerance at both the seed germination and seedling stage. Unexpectedly, GsGF14o transgenic lines showed reduced water loss and transpiration rates compared with wild-type plants, which was demonstrated to be the consequence of the decreased stomatal size. At the same time, the smaller stomata due to GsGF14o overexpression led to a relatively slow net photosynthesis rate, which led to a growth penalty under drought stress. We further demonstrated that GsGF14o overexpression caused deficits in root hair formation and development, and thereby reduced the water intake capacity of the transgenic root system. In addition, GsGF14o overexpression down-regulated the transcript levels of drought-responsive marker genes. Finally, we also investigated the tissue-specific accumulation of GsGF14o by using a GUS activity assay. Collectively, the results presented here confirm that GsGF14o plays a dual role in drought stress responses through its involvement in the regulation of stomatal size and root hair development.
MNPs@MOF catalysts
obtained by encapsulating metal nanoparticles
(NPs) into metal–organic frameworks (MOFs) show fascinating
performance in heterogeneous catalysis. The improvement of catalytic
activity and reusability of MNPs@MOF catalysts has been a great challenge
for a long time. Herein, we demonstrate well-designed Pd/MOFs, featuring
hollow double-shell structure and magnetic property, exhibiting high
reusability, efficient catalytic activity, and size selectivity for
hydrogenation reaction. The as-synthesized Pd/MOF, denoted as Void nFe3O4@Pd/ZIF-8@ZIF-8, possesses diverse
functional structural features. The hollow cavity can improve mass
transfer; superparamagnetic Fe3O4 NPs embedded
in the inner MOF shell can enhance the separation and recyclability;
Pd NPs are highly dispersed in the matrix of the inner MOF shell,
and the outer MOF shell acts as a protector to prevent the leaching
of Pd NPs and a sieve to achieve size selectivity. As a proof of concept,
the Void nFe3O4@Pd/ZIF-8@ZIF-8
catalyst exhibited excellent performance for the hydrogenation of
styrene at room temperature. The activity only reduced 10% after 20
cycles for the higher conversions (>90%), and the lower conversion
only decreased 3.6% (from 32.5 to 28.9% conversion) after twenty consecutive
cycles, indicating the good and intrinsic reusability of the catalyst.
The proposed structure in this work provides a strategy to effectively
improve the reusability of MNPs@MOF catalysts, which would increase
their practical applications.
A CdS/MoS2 heterojunction with uniform loading of CdS nanoparticles, porous structure, and controllable heterojunction surface was synthesized from a core–shell MoS2@Cd-MOF precursor and exhibited a high photocatalytic H2 evolution rate.
Germinal center (GC) B cell response is critical for pathogen protection. Chen et al. find that Uhrf1 is up-regulated by the c-Myc–AP4 axis and plays an essential role in GC B cell expansion and affinity maturation.
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