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.

No abstract

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.

The Chinese cordyceps, regarded as the ‘Himalayan Viagra’, is highly valued for its medicinal benefits. The decline of its yield due to over-exploitation and increased market demand have stimulated efforts to artificially cultivate Chinese cordyceps for over half a century. However, successful cultivation of Chinese cordyceps through caterpillar infection by the fungus Ophiocordyceps sinensis (Berk.) and the induction of the fruiting body from each mummified cadaver remains difficult for its complex life cycle. Herein, we report the developmental dynamics of hyphal bodies in hemolymph of injected Thitarodes xiaojinensis (Tu, Ma & Zhang) larvae and the success in artificial cultivation of sexual fruiting bodies from the mummified cadavers in the low-altitude area. We find that not only the numbers of hyphal bodies but also the conversion of hyphal bodies into hyphae played important roles in the mummification of the injected larvae. This cultivation will be beneficial for sustainable utilization of natural resources and provides the possibility for further research on the mechanism of the interaction between pathogenic fungus and host insect.

No abstract

Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) is the sensitive method to quantify the expression levels of target genes on the basis of endogenous control. An appropriate reference gene set for normalization is essential for reliable results. The ghost moth, Thitarodes armoricanus, a host species of a medicinal fungus, Ophiocordyceps sinensis, is an economically important member of the Lepidoptera. Recent studies have focused on the mechanism of adaptation of this species to its high-altitude environment and host immune response to O. sinensis infection and RT-qPCR is commonly used in these studies to decipher the genetic basis of physiological functions. However, a thorough assessment of candidate reference genes in the genus Thitarodes is lacking. Here, the expression levels of eight candidate reference genes (ACT, EF, EIF4A, GAPDH, G6PDH, RPL13A, TUB and 18S) in T. armoricanus at different developmental stages and in different body parts of the seventh instar larvae were analyzed, along with larvae kept under low temperatures, larvae exposed to two fungal infections and larvae fed different diets. Three established software programs–Bestkeeper, geNorm and NormFinder–were employed to calculate variation among the treatments. The results revealed that the best-suited reference genes differed across the treatments, with EF, EIF4A and GAPDH found to be the best suited for the different developmental stages and larvae body parts; EF, EIF4A and RPL13A found to be the best suited for low-temperature challenge; and EF, EIF4A and TUB found to be the best suited for the fungal infections and dietary treatments. This study thus further contributes to the establishment of an accurate method for normalizing RT-qPCR results for T. armoricanus and serves as a reference for gene expression studies of related insect species.

No abstract