cis基因交换形成RHD-CE(2-9)-D等位基因

以往通过基因组DNA分析,分别在高加索人和中国人中观察到少数Rh阴性个体存在RHD基因第1和第10外显子,但是该等位基因形成的具体分子机制尚有争论。本文分别针对RHD基因mRNA的5′-和3′-非编码区设计一对特异性引物,通过逆转录PCR（RT-PCR）和cDNA测序,分析2例RHD基因阳性（拥有第1和第10外显子）、D抗原表型阴性个体的全长mRNA/cDNA序列,同时以1例正常Rh阳性个体（CcDDee）作对照。结果正常Rh阳性个体拥有正常RHD基因mRNA,2名携带RHD基因的Rh阴性个体则均检出存在与正常RHD基因或RHCE基因转录产物相同长度、以及相同外显子构成的mRNA,但该转录子的第1和第10外显子及3′-非编码区序列与RHD基因一致,而第2～9外显子全部序列与RHCE(e)基因mRNA相同,表明2名个体均存在RHD-CE(2~9)-D融合RHD等位基因,即其RHD基因的第2～9外显子被同源RHCE(e)基因替换,导致不能编码正常RhD蛋白,形成个体D抗原阴性表型。     

基于稀疏编码和SCG BPNN的鳞翅目昆虫图像识别

【目的】为了给林业、 农业或植物检疫等行业人员提供一种方便快捷的昆虫种类识别方法, 本文提出了一种新颖的鳞翅目昆虫图像自动识别方法。【方法】首先通过预处理对采集的昆虫标本图像去除背景, 分割出双翅, 并对翅图像的位置进行校正。然后把校正后的翅面分割成多个超像素, 用每个超像素的l, a, b颜色及x, y坐标平均值作为其特征数据。接下来用稀疏编码(SC)算法训练码本、 生成编码并汇集成特征向量训练量化共轭梯度反向传播神经网络（SCG BPNN）, 并用得到的BPNN进行分类识别。【结果】该方法对包含576个样本的昆虫图像的数据库进行了测试, 取得了高于99%的识别正确率, 并有理想的时间性能、 鲁棒性及稳定性。【结论】实验结果证明了本文方法在识别鳞翅目昆虫图像上的有效性。     

The low levels of eicosapentaenoic acid in rat brain phospholipids are maintained via multiple redundant mechanisms

Brain eicosapentaenoic acid (EPA) levels are 250- to 300-fold lower than docosahexaenoic acid (DHA), at least partly, because EPA is rapidly β-oxidized and lost from brain phospholipids. Therefore, we examined if β-oxidation was necessary for maintaining low EPA levels by inhibiting β-oxidation with methyl palmoxirate (MEP). Furthermore, because other metabolic differences between DHA and EPA may also contribute to their vastly different levels, this study aimed to quantify the incorporation and turnover of DHA and EPA into brain phospholipids. Fifteen-week-old rats were subjected to vehicle or MEP prior to a 5 min intravenous infusion of ¹⁴C-palmitate, ¹⁴C-DHA, or ¹⁴C-EPA. MEP reduced the radioactivity of brain aqueous fractions for ¹⁴C-palmitate-, ¹⁴C-EPA-, and ¹⁴C-DHA-infused rats by 74, 54, and 23%, respectively; while it increased the net rate of incorporation of plasma unesterified palmitate into choline glycerophospholipids and phosphatidylinositol and EPA into ethanolamine glycerophospholipids and phosphatidylserine. MEP also increased the synthesis of n-3 docosapentaenoic acid (n-3 DPA) from EPA. Moreover, the recycling of EPA into brain phospholipids was 154-fold lower than DHA. Therefore, the low levels of EPA in the brain are maintained by multiple redundant pathways including β-oxidation, decreased incorporation from plasma unesterified FA pool, elongation/desaturation to n-3 DPA, and lower recycling within brain phospholipids.     

Sulforaphene enhances radiosensitivity of hepatocellular carcinoma through suppression of the NF‐κB pathway

Sulforaphene (SFE), a naturally occurring isothiocyanate found in cruciferous vegetables, has attracted increasing attention for its anti‐cancer effect in many cancers, including hepatocellular carcinoma (HCC). However, the precise role of SFE in the radiosensitivity of HCC is still unclear. Here, cell proliferation and apoptosis were detected by MTT and flow cytometry assay, respectively. The activity of NF‐κB was further evaluated by ELISA. We also observed the effect of SFE and/or radiation on tumor growth. The results showed that SFE inhibited cell proliferation and induced apoptosis in HCC cells. Radiation increased NF‐kB activity, while PDTC, a NF‐kB inhibitor, enhanced radiation‐induced cell death. SFE inhibited NF‐kB activity and the downstream gene expressions of the NF‐kB pathway in HCC cells. Moreover, SFE enhanced the inhibitory effect of radiation on tumor growth both in vitro and in vivo. This study indicated that SFE sensitized the radiosensitivity of HCC by blocking the NF‐kB pathway.     

Design,synthesis and biological evaluation of novel oseltamivir derivatives as potent neuraminidase inhibitors

Neuraminidase (NA) is one of the particular potential targets for novel antiviral therapy. In this work, a series of neuraminidase inhibitors with the cyclohexene scaffold were studied based upon the combination of 3D-QSAR, molecular docking, and molecular dynamics techniques. The results indicate that the built 3D-QSAR models yield reliable statistical information: the correlation coefficient (r²) and cross-validation coefficient (q²) of CoMFA (comparative molecular field analysis) are 0.992 and 0.819; the r² and q² of CoMSIA (comparative molecular similarity analysis) are 0.992 and 0.863, respectively. Molecular docking and MD simulations were conducted to confirm the detailed binding mode of enzyme-inhibitor system. The new NA inhibitors had been designed, synthesized, and their inhibitory activities against group-1 neuraminidase were determined. One agent displayed excellent neuraminidase inhibition, with IC₅₀ value of 39.6?μM against NA, while IC₅₀ value for oseltamivir is 61.1?μM. This compound may be further investigated for the treatment of infection by the new type influenza virus.     

Silencing LINC00504 inhibits cell proliferation,invasion as well as migration and promotes cell apoptosis in lung cancer cells via upregulating miR-876-3p

LINC00504 acts as an oncogene and associates with unfavorable prognosis in patients with lung cancer. Silencing LINC00504 may be a promising strategy for treatment of lung cancer and its effects were firstly investigated in lung cancer cells this study. The gene expression level of miR-876-3p as well as LINC00504 were measured via PCR assay. The cell proliferation was investigated through Cell Counting Kit-8 (CCK-8) assay and colony formation assay. Flow cytometry was applied for detection of cell apoptosis. Wound healing and transwell assay were performed for measurement of cell migration and invasion respectively. The apoptosis related protein expressions were measured by western blot. Luciferase report assay was conducted for verification the target gene. LINC00504 was higher expressed in five types of lung cancer cells studied herein when compared with the control normal cells. LINC00504 knockdown exerted inhibitory effects on cell apoptosis, cell migration as well as cell invasion and promoted cell apoptosis. All the effects mentioned above were counteracted by miR-876-3p inhibitor. Silencing LINC00504 possessed anti-proliferation, repression of cell invasion as well as migration and pro-apoptosis effects via targeting up-regulation of miR-876-3p in lung cancer cells, proving the new therapeutic targets and highlighting the potential application in future diagnosis and treatment in lung cancer.     

Whole‐genome resequencing reveals the pleistocene temporal dynamics of Branchiostoma belcheri and Branchiostoma floridae populations

Global climatic fluctuations governed the ancestral demographic histories of species and contributed to place the current population status into a more extensive ecological and evolutionary context. Genetic variations will leave unambiguous signatures in the patterns of intraspecific genetic variation in extant species since the genome of each individual is an imperfect mosaic of the ancestral genomes. Here, we report the genome sequences of 20 Branchiostoma individuals by whole‐genome resequencing strategy. We detected over 140 million genomic variations for each Branchiostoma individual. In particular, we applied the pairwise sequentially Markovian coalescent (PSMC) method to estimate the trajectories of changes in the effective population size (N_e) of Branchiostoma population during the Pleistocene. We evaluated the threshold of sequencing depth for proper inference of demographic histories using PSMC was ≥25×. The PSMC results highlight the role of historical global climatic fluctuations in the long‐term population dynamics of Branchiostoma. The inferred ancestral N_e of the Branchiostoma belcheri populations from Zhanjiang and Xiamen (China) seawaters was different in amplitude before the first (mutation rate = 3 × 10^?9) or third glaciation (mutation rate = 9 × 10^?9) of the Pleistocene, indicating that the two populations most probably started to evolve in isolation in their respective seas after the first or third glaciation of the Pleistocene. A pronounced population bottleneck coinciding with the last glacial maximum was observed in all Branchiostoma individuals, followed by a population expansion occurred during the late Pleistocene. Species that have experienced long‐term declines may be especially vulnerable to recent anthropogenic activities. Recently, the industrial pollution and the exploitation of sea sand have destroyed the harmonious living environment of amphioxus species. In the future, we need to protect the habitat of Branchiostoma and make full use of these detected genetic variations to facilitate the functional study of Branchiostoma for adaptation to local environments.     

黑曲霉木质纤维素降解酶基因的可变剪接分析及验证

黑曲霉Aspergillus niger因能够产生大量的木质纤维素降解酶而在木质纤维素资源利用中发挥重要作用。目前,有关黑曲霉基因组中与木质纤维素降解相关的基因是否存在可变剪接的情况尚不清楚。本研究以黑曲霉CBS513.88菌株为研究对象,采用rMATS和ABLas两种方法对黑曲霉在葡萄糖为唯一碳源(G组)和小麦秸秆为唯一碳源(WS组)下的56个木质纤维素降解酶基因的可变剪接事件进行分析,并通过RT-PCR扩增和内含子特异性扩增对3个典型基因的可变剪接体进行了验证。结果表明,ABLas可变剪接分析算法相较于rMATS分析算法更为准确,ABLas分析算法显示G组和WS组共有21个木质纤维素降解酶基因出现了可变剪接,可变剪接类型以内含子保留(IR)为主,占所有可变剪接事件的82.85%。另外,G组和WS组发生可变剪接的木质纤维素降解酶基因也有所不同：G组发生可变剪接的基因为13个,WS组发生可变剪接的基因为14个,两组都发生可变剪接的基因为6个,这表明黑曲霉木质纤维素降解酶基因的可变剪接在不同生长条件下存在差异,另一方面,黑曲霉中众多可变剪接体的存在也为开发新型的木质纤维素降解酶资源提供基础。     

RBP differentiation contributes to selective transmissibility of OPT3 mRNAs

Long-distance mobile mRNAs play key roles in gene regulatory networks that control plant development and stress tolerance. However, the mechanisms underlying species-specific delivery of mRNA still need to be elucidated. Here, the use of grafts involving highly heterozygous apple (Malus) genotypes allowed us to demonstrate that apple (Malus domestica) oligopeptide transporter3 (MdOPT3) mRNA can be transported over a long distance, from the leaf to the root, to regulate iron uptake; however, the mRNA of Arabidopsis (Arabidopsis thaliana) oligopeptide transporter 3 (AtOPT3), the MdOPT3 homolog from A. thaliana, does not move from shoot to root. Reciprocal heterologous expression of the two types of mRNAs showed that the immobile AtOPT3 became mobile and moved from the shoot to the root in two woody species, Malus and Populus, while the mobile MdOPT3 became immobile in two herbaceous species, A. thaliana and tomato (Solanum lycopersicum). Furthermore, we demonstrated that the different transmissibility of OPT3 in A. thaliana and Malus might be caused by divergence in RNA-binding proteins between herbaceous and woody plants. This study provides insights into mechanisms underlying differences in mRNA mobility and validates the important physiological functions associated with this process.

The long-distance movement of OPT3 is selective between herbaceous and woody plants as shown using Malus and Arabidopsis thaliana plants.