Morphological features,development and reproduction of Melittobia acasta on Bombus terrestris

Morphological features, development and reproduction behavior of the parasite Melittobia acasta (Walker) were studied when reared on the pupae of the bumblebee Bombus terrestris L. in the laboratory under 23°C, 50% relative humidity and 12 h light : 12 h dark conditions. The parasites laid transparent white and elongated eggs. Newly hatched larval size and shape were very similar to eggs but they were identified by their body segments. Larvae increased their body size through moulting and transformed into a vermiform shape. Male pupae were shiny brown with dots. The female pupae were distinguished by their black shiny color, shorter size and the presence of compound eyes. Adult male pupae were dark brown and dwarf‐winged, whereas female pupae were macropterous and brachypterous. Reproduction took place by fertilization and also parthenogenetically. Mean fecundity within 5 days by mated (47.9 ± 30.5 female^?1) and virgin (7.4 ± 6.8 female^?1) females were statistically different. Mated females laid fertilized eggs that produced adult males or females, whereas virgin females laid unfertilized eggs that produced males. Development durations of the virgin female originated eggs, larvae, pupae and adults were statistically identical with those of mated females. The parasites were female‐biased and foundress number did not affect offspring sex ratio. This study shows that both mated and virgin females of M. acasta can produce many offspring on B. terrestris pupae within a short period, indicating that they are dangerous parasites of the bumblebee in a mass rearing system.     

Multi-compartmental modeling of SORLA's influence on amyloidogenic processing in Alzheimer's disease

ABSTRACT: BACKGROUND: Proteolytic breakdown of the amyloid precursor protein (APP) by secretases is a complex cellular process that results in formation of neurotoxic A? peptides, causative of neurodegeneration in Alzheimer's disease (AD). Processing involves monomeric and dimeric forms of APP that traffic through distinct cellular compartments where the various secretases reside. Amyloidogenic processing is also influenced by modifiers such as sorting receptor-related protein (SORLA), an inhibitor of APP breakdown and major AD risk factor. RESULTS: In this study, we developed a multi-compartment model to simulate the complexity of APP processing in neurons and to accurately describe the effects of SORLA on these processes. Based on dose-response data, our study concludes that SORLA specifically impairs processing of APP dimers, the preferred secretase substrate. In addition, SORLA alters the dynamic behavior of ?-secretase, the enzyme responsible for the initial step in the amyloidogenic processing cascade. CONCLUSIONS: Our multi-compartment model represents a major conceptual advance over single-compartment models previously used to simulate APP processing; and it identified APP dimers and ?-secretase as the two distinct targets of the inhibitory action of SORLA in Alzheimer's disease.     

Tesk1 interacts with Spry2 to abrogate its inhibition of ERK phosphorylation downstream of receptor tyrosine kinase signaling

The Sprouty (Spry) proteins function as inhibitors of the Ras-ERK pathway downstream of various receptor tyrosine kinases. In this study, we have identified Tesk1 (testicular protein kinase 1) as a novel regulator of Spry2 function. Endogenous Tesk1 and Spry2 exist in a complex in cell lines and mouse tissues. Tesk1 coexpression relocalizes Spry2 to vesicles including endosomes, inhibiting its translocation to membrane ruffles upon growth factor stimulation. Independent of its kinase activity, Tesk1 binding leads to a loss of Spry2 function as an inhibitor of ERK phosphorylation and reverses inhibition of basic fibroblast growth factor (bFGF)- and nerve growth factor-induced neurite outgrowth in PC12 cells by Spry2. Furthermore, depletion of endogenous Tesk1 in PC12 cells leads to a reduction in neurite outgrowth induced by bFGF. Tesk1 nullifies the inhibitory effect of Spry2 by abrogating its interaction with the adaptor protein Grb2 and interfering with its serine dephosphorylation upon bFGF and FGF receptor 1 stimulation by impeding its binding to the catalytic subunit of protein phosphatase 2A. A construct of Tesk1 that binds to Spry2 but does not localize to the vesicles does not interfere with its function, highlighting the importance of subcellular localization of Tesk1 in this context. Conversely, Tesk1 does not affect interaction of Spry2 with the E3 ubiquitin ligase, c-Cbl, and consequently, does not affect its inhibition of Cbl-mediated ubiquitination of the epidermal growth factor receptor. By selectively modulating the downstream effects of Spry2, Tesk1 may thus serve as a molecular determinant of the signaling outcome.     

模拟微重力条件下大鼠肝细胞三维培养支架材料的筛选（简报）

组织工程是一门新兴的边缘学科,它是利用体外培养的人体功能细胞与适当的细胞外基质或支架材料相结合,然后将其移植到体内病损部位以期达到修复目的。微重力组织工程(Microgravity Tissue Engineering)是近年来由美国空间生物技术研究人员开创的一个独特研究领域,其核心技术是     

CA9 transcriptional expression determines prognosis and tumour grade in tongue squamous cell carcinoma patients

CA9 is a member of the carbonic anhydrases’ family, that is often expressed in cancer cells under hypoxic condition. However, the role of CA9 in the molecular mechanisms of tongue squamous cell carcinoma (TSCC) pathogenesis remains unclear. CA9 expression was analysed using the TCGA database, and its influence on survival was performed using Kaplan-Meier, LASSO and COX regression analyses. The correlation between CA9 and immune infiltration was investigated by CIBERSORT and ESTIMATE. Moreover, the relationship between CA9 expression and downstream molecular regulation pathways was analysed by GSEA, GO and WGCNA. CA9 expression correlated with clinical prognosis and tumour grade in TSCC. Moreover, CA9 expression potentially contributes to the regulation of cancer cell differentiation and mediates tumour-associated genes and signalling pathways, including apoptosis, hypoxia, G2M checkpoint, PI3K/AKR/mTOR signalling and TGF-beta signalling pathways. However, the follicular helper T cells, regulatory T cells, immune and stromal scores showed no significance between high and low CA9 expression groups. These findings suggested that CA9 plays a critical role of TSCC prognosis and tumour grade. CA9 expression significantly correlated with the regulation of cell differentiation, various oncogenes and cancer-associated pathways.     

A Proteomics Sample Preparation Method for Mature,Recalcitrant Leaves of Perennial Plants

Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie). An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants.     

Synthesis of chiral fluorine-tagged reference standards for the 19F NMR-based stereochemical analysis of sulfoxides at trace analytical levels

Chiral fluorine-tagged sulfoxides of known absolute configuration have been synthesized. These compounds are required as reference standards to validate a ¹⁹F NMR-based micromethod for the stereochemical analysis of biosynthetic fatty acyl sulfoxides.