The transformer (tra) gene appears to act as the genetic switch that promotes female development by interaction with the transformer2 (tra-2) gene in several dipteran species including the Medfly, housefly and Drosophila melanogaster. In this study, we describe the isolation, expression and function of tra and tra-2 in the economically important agricultural pest, the oriental fruit fly, Bactrocera dorsalis (Hendel). Bdtra and Bdtra-2 are similar to their homologs from other tephritid species. Bdtra demonstrated sex-specific transcripts: one transcript in females and two transcripts in males. In contrast, Bdtra-2 only had one transcript that was common to males and females, which was transcribed continuously in different adult tissues and developmental stages. Bdtra-2 and the female form of Bdtra were maternally inherited in eggs, whereas the male form of Bdtra was not detectable until embryos of 1 and 2 h after egg laying. Function analyses of Bdtra and Bdtra-2 indicated that both were indispensable for female development, as nearly 100% males were obtained with embryonic RNAi against either Bdtra or Bdtra-2. The fertility of these RNAi-generated males was subsequently tested. More than 80% of RNAi-generated males could mate and the mated females could lay eggs, but only 40-48.6% males gave rise to progeny. In XX-reversed males and intersex individuals, no clear female gonadal morphology was observed after dissection. These results shed light on the development of a genetic sexing system with male-only release for this agricultural pest.

Since 1 July 2018, the GRAPES (Global/Regional Assimilation and PrEdiction System) global 4‐dimensional variational (4D‐Var) data assimilation system has been in operation at the China Meteorological Administration (CMA). In this study, the GRAPES global 4D‐Var data assimilation system is comprehensively introduced. This system applies the non‐hydrostatic global tangent‐linear model (TLM) and the adjoint model (ADM) for the first time. The use of a digital filter as a weak constraint is achieved. A series of linear physical processes is developed, including vertical diffusion, subgrid‐scale orographic parametrization, large‐scale condensation, and cumulus convection parametrization. The vertical diffusion and subgrid‐scale orographic schemes are used in the operational suite and the linear convection parametrization and large‐scale condensation scheme remain under assessment. The Lanczos and conjugate gradient (Lanczos‐CG) algorithm and the limited‐memory Broyden‐Fletcher‐Goldfarb‐Shanno (L‐BFGS) algorithm are also developed. In terms of computational optimization, the total computational time of the GRAPES global TLM and ADM is approximately threefold that of the GRAPES global nonlinear model (NLM). Before it became operational, a one‐year retrospective trial was performed on the GRAPES global 4D‐Var data assimilation system. The entire system was stable, and the analysis and forecasting performances were significantly better than those of the 3D‐Var data assimilation system, especially in the Southern Hemisphere.

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Nanocarriers are widely used for delivering drugs to tumors and their development is progressing steadily. In this study, a pH sensitive mesoporous silica nanocarrier, RuNHC@MSNs-CTS-Biotin (CTS = chitosan), is developed for the targeted delivery and controlled release of a ruthenium(ii) N-heterocyclic carbene (RuNHC) complex. The RuNHC@MSNs-CTS-Biotin nanoparticles were composed of RuNHC loaded mesoporous silica nanoparticles (MSNs) coated with chitosan-biotin (CTS-Biotin) conjugates. CTS traps the RuNHC complex inside the mesopores and biotin is used as a targeting ligand to improve specific cell uptake. The particle size of RuNHC@MSNs-CTS-Biotin was around 90 nm with a zeta potential of 12.0 mV and the RuNHC loading capacity was 26.31%. The release of RuNHC from RuNHC@MSNs-CTS-Biotin was in a pH-dependent manner, and it exhibited a 59.71% terminal release ratio at pH 5.0, but almost no release under neutral conditions (pH 7.4). Its in vitro cellular uptake and anticancer activity revealed that RuNHC@MSNs-CTS-Biotin could be selectively internalized in cancer cells by biotin receptor-mediated endocytosis and this resulted in a significant improvement in anticancer activities as compared with the RuNHC complex. This multifunctional nanocarrier system provides a promising platform for the development of precisely controllable cancer therapy.