鸡NRG4基因组及转录本结构分析

神经调节蛋白4(neuregulin 4,NRG4)是一个重要的脂肪细胞因子,在维持哺乳动物能量平衡、调节糖脂代谢和预防非酒精性脂肪性肝病中起着非常重要的作用。目前,人NRG4基因的基因组结构、转录异构体和蛋白异构体等已有深入的研究。本实验室前期研究显示,鸡脂肪组织也表达NRG4,但是目前有关鸡NRG4(chicken NRG4,cNRG4)基因的基因组结构、转录异构体和蛋白异构体尚不清楚。为此,本研究采用RACE(rapid-amplification of cDNA ends)和RT-PCR(reverse transcription-PCR)等技术,系统开展了cNRG4基因的基因组和转录本的结构分析。结果发现,cNRG4基因编码区很小,但该基因却非常复杂,存在选择性转录起始位点、选择性拼接、内含子滞留、隐匿外显子和选择性多聚腺苷酸化,这导致cNRG4基因产生4种不同的5ʹUTR异构体(cNRG4 A、cNRG4 B、cNRG4 C和cNRG4 D)和6种不同的3ʹUTR异构体(cNRG4 a、cNRG4 b、cNRG4 c、cNRG4 d、cNRG4 e和cNRG4 f)。基因组结构分析发现,cNRG4基因跨越基因组21,969 bp(Chr.10:3,490,314~3,512,282),由11个外显子和10个内含子构成。与NCBI数据库中的cNRG4基因mRNA序列(NM_001030544.4)相比,本研究发现了cNRG4基因的2个新外显子和1个隐匿外显子。生物信息学分析、RT-PCR、克隆和测序分析发现,cNRG4基因能编码3种蛋白异构体(cNRG4-1、cNRG4-2和cNRG4-3)。本研究为进一步开展cNRG4基因的功能和调控研究奠定了基础。

鸡快慢羽性状遗传学基础分析综合实验探索与实践

随着全国"卓越农林人才教育培养计划"的开展,我校动物科学专业设置了"卓越班",以突出培养学生的系统思维和创新创业能力为目标开展了系列教育教学管理和课程改革。为此,我们以"鸡快、慢羽性状"为实验对象,设计了"鸡快慢羽性状遗传学基础分析"综合实验,突出培养学生用理论知识解决生产实践问题的思维和能力。本文重点介绍了该实验作为动物遗传学实验教学案例的实施过程及效果,首先从鸡的表型观察逐步深入到遗传学基础分析,利用遗传学理论指导鸡快、慢羽品系培育的育种实践。实验内容涉及伴性遗传规律和性别决定机制等遗传学理论知识,同时还涉及基因组DNA提取、基因扩增、酶切及电泳分析等一系列分子遗传学的技术方法。不仅有利于学生综合分析能力和专业技能的掌握,还有助于培养学生对动物科学专业的科研兴趣和创新意识。此综合性实验还展现了用遗传学理论指导动物品种培育实践过程,符合动物科学专业复合应用型人才培养目标的要求,其中的教学理念和方法可推广应用于其他生物学实验教学。

选择性多聚腺苷酸化的生物学效应及其调控机制研究进展

真核生物基因的前体mRNA(pre-mRNA)及一些lncRNA在成熟过程中其3'端会发生剪切和多聚腺苷酸化反应(cleavage and polyadenylation, C/P),C/P的发生需要多聚腺苷酸化信号(polyadenylation signal, PAS)的存在。选择性多聚腺苷酸化(alternative cleavage and polyadenylation, APA)是指具有多个PAS的基因,在其mRNA3'端成熟过程中,由于选择不同的PAS,导致产生出多个3'UTR长度和序列组成不同的转录异构体。3'UTR长度和序列的不同会影响mRNA的稳定性、翻译效率、运输和细胞定位等,因此APA是真核生物的一个重要转录后调控方式。近年来,对大量动物、植物及酵母的基因组测序分析发现,APA在真核生物广泛存在,针对APA的生物学效应和调控机制开展了一系列研究。目前已鉴定出许多APA调控的顺式调控元件和反式作用因子。本文重点介绍了APA生物学效应和调控机制的最新研究进展,并探讨了未来APA调控的研究方向。

Archimedean copula estimation of distribution algorithm based on artificial bee colony algorithm

The artificial bee colony （ABC） algorithm is a com- petitive stochastic population-based optimization algorithm. How- ever, the ABC algorithm does not use the social information and lacks the knowledge of the problem structure, which leads to in- sufficiency in both convergent speed and searching precision. Archimedean copula estimation of distribution algorithm （ACEDA） is a relatively simple, time-economic and multivariate correlated EDA. This paper proposes a novel hybrid algorithm based on the ABC algorithm and ACEDA called Archimedean copula estima- tion of distribution based on the artificial bee colony （ACABC） algorithm. The hybrid algorithm utilizes ACEDA to estimate the distribution model and then uses the information to help artificial bees to search more efficiently in the search space. Six bench- mark functions are introduced to assess the performance of the ACABC algorithm on numerical function optimization. Experimen- tal results show that the ACABC algorithm converges much faster with greater precision compared with the ABC algorithm, ACEDA and the global best （gbest）-guided ABC （GABC） algorithm in most of the experiments.

鸡胰岛素降解酶基因环状转录本克隆及其表达规律

本课题组前期通过高通量测序发现,鸡胰岛素降解酶(insulin degrading enzyme, IDE)基因可能存在一个环状转录本。为确定IDE基因环状转录本(circIDE)的真实存在,探究其表达规律,本研究以吉林芦花鸡为研究对象,通过PCR扩增和测序验证了circIDE的真实存在,通过RNase R处理和反转录证实了circIDE的环形结构,通过qRT-PCR分析circIDE和IDE mRNA的时空表达规律,并对比分析了circIDE和线性IDE mRNA在正常体型芦花鸡和GHR突变的矮小体型芦花鸡中的表达差异。结果表明:鸡circIDE全长为1332 nt,由IDE基因外显子2~11环化形成。RNase R耐受性分析表明,鸡circIDE具备环形分子的一般特征,不易被RNase R降解。与oligo-d(T)18引物相比,随机引物对circIDE具有较高的反转录效率,进一步说明circIDE是一个不含poly(A)的环状结构分子。组织表达谱结果表明,circIDE在1周龄和12周龄正常体型芦花鸡肝脏和心脏高表达,在胸肌和腿肌中低表达;circIDE在肝脏组织的时序表达谱结果表明,circIDE在鸡6周龄之前为低表达,在8周龄以后表现为高表达;正常与矮小体型芦花鸡品系间circIDE表达量对比分析表明,正常体型芦花鸡circIDE表达水平高于矮小体型芦花鸡,其中在肝脏组织中差异显著(P<0.05)。本研究证实了鸡IDE基因存在一个环状转录本circIDE,并初步揭示了circIDE的表达规律,circIDE在正常体型和矮小体型芦花鸡肝脏组织中表达量存在差异,本研究结果为深入开展鸡circIDE的生物学功能及其在鸡生长发育过程中的作用机制奠定了基础。

GPP Based Open Cellular Network Towards 5G

Due to 5G's stringent and uncertainty traffic requirements,open ecosystem would be one inevitable way to develop 5G.On the other hand,GPP based mobile communication becomes appealing recently attributed to its striking advantage in flexibility and re-configurability.In this paper,both the advantages and challenges of GPP platform are detailed analyzed.Furthermore,both GPP based software and hardware architectures for open 5G are presented and the performances of real-time signal processing and power consumption are also evaluated.The evaluation results indicate that turbo and power consumption may be another challengeable problem should be further solved to meet the requirements of realistic deployments.

A review of crosstalk research for plasmonic waveguides

Plasmonic waveguides,as a competitive candidate,have been widely studied in rapid developing photonic integrated circuits(PICs)and optical interconnection fields.However,crosstalk between plasmonic waveguides is a critical issue that has to be considered in practice.Actually,crosstalk dominates the ultimate integration density of the planar photonic circuits.This paper reviews the recent research work on evaluation methods and crosstalk suppression approaches of plasmonic waveguides.Three crosstalk evaluation methods based on comparison of specific parameters of waveguides have been summarized.Furthermore,four specific approaches to reduce crosstalk have been illustrated as two categories according to their impacts on waveguide performances and the whole circuit.One means of crosstalk suppression is changing the placement of waveguides,which could maintain the transmission characteristics of the original waveguide.The other means is inserting medium,which has the advantage of occupying smaller space compared to the first method.Consequently,to suppress crosstalk between plasmonic waveguides,one should choose suitable approach.

Decomposition dynamics and ecological stoichiometry of Quercus acutissima and Pinus densiflora litter in the Grain to Green Program Area of northern China

Litter decomposition and ecological stoichiometry of nutrient release is an important part of material cycling and energy flow in forest ecosystems.In a study of the ecological stoichiometry and nutrient release during litter decomposition in a pine–oak forest ecosystem of the Grain to Green Program(GTGP)area of northern China,a typical pine and oak species(PDS:Pinus densiflora Sieb.,QAC:Quercus acutissima Carr.)were selected in the Taiyi Mountain study area.The ecological stoichiometry characteristics of carbon(C),nitrogen(N)and phosphorus(P)and litter decomposition dynamics were studied by field sampling and quantitative analyses.The results showed the following.(1)The decomposition dynamics of both litters was slow-fast-slow.The most important climatic factor affecting the litter decomposition rate from May to October was precipitation and temperature from November to April of the following year.(2)Throughout the 300-day study,in both litters,C of the two litters was released,N first accumulated and was then released,and P exhibited a release-accumulate-release pattern.(3)C:P was significantly higher than C:N and N:P(p<0.05);the C:N of PSD litter was higher than that of QAC(p<0.05),but the N:P of QAC litter was higher than that of PSD litter(p<0.05).The C:N of both litters was very high in the study area,indicating that the nutrient release ability during litter decomposition in the two typical pine–oak forest ecosystems was relatively weak;therefore,more attention should be paid to nitrogen-fixing species and mixed forests in the GTGP area of northern China.

过渡金属催化烯烃和炔烃合成1,3-共轭二烯化合物研究进展

1,3-共轭二烯是许多天然产物和药物的关键结构单元.由于共轭烯烃具有特殊的化学性质,它们在有机合成和材料科学中起着核心作用.目前,1,3-共轭二烯的合成主要是通过过渡金属催化的方法实现,通过该方法科研工作者构建了一系列1,3-二烯骨架,丰富了共轭二烯类化合物的结构多样性,同时也扩展了二烯化合物的应用范围.以过渡金属催化剂的种类不同为主线,分类对1,3-二烯的合成进行了综述,并对其发展前景予以展望.

Beclin 1 cleavage by caspase-3 inactivates autophagy and promotes apoptosis

Autophagy and apoptosis are both highly regulated biological processes that play essential roles in tissue homeostasis,development and diseases.Autophagy is also described as a mechanism of death pathways,however,the precise mechanism of how autophagy links to cell death remains to be fully understood.Beclin 1 is a dual regulator for both autophagy and apoptosis.In this study we found that Beclin 1 was a substrate of caspase-3 with two cleavage sites at positions 124 and 149,respectively.Furthermore,the autophagosome formation occurred,followed by the appearance of morphological hallmarks of apoptosis after staurosporine treatment.The cleavage products of Beclin 1 reduced autophagy and promoted apoptosis in HeLa cells and the cells in which Beclin 1 was stably knocked down by specific shRNA.In addition,the cleavage of Beclin 1 resulted in abrogating the interaction between Bcl-2 with Beclin 1,which could be blocked by z-VAD-fmk.Thus,our results suggest that the cleavage of Beclin 1 by caspase-3 may contribute to inactivate autophagy leading towards augmented apoptosis.

The emerging roles of vacuolar-type ATPase-dependent Lysosomal acidification in neurodegenerative diseases

Background Lysosomes digest extracellular material from the endocytic pathway and intracellular material from the autophagic pathway.This process is performed by the resident hydrolytic enzymes activated by the highly acidic pH within the lysosomal lumen.Lysosome pH gradients are mainly maintained by the vacuolar(H+)ATPase(or V-ATPase),which pumps protons into lysosomal lumen by consuming ATP.Dysfunction of V-ATPase affects lysosomal acidification,which disrupts the clearance of substrates and leads to many disorders,including neurodegenerative diseases.Main body As a large multi-subunit complex,the V-ATPase is composed of an integral membrane V0 domain involved in proton translocation and a peripheral V1 domain catalyzing ATP hydrolysis.The canonical functions of V-ATPase rely on its H+-pumping ability in multiple vesicle organelles to regulate endocytic traffic,protein processing and degradation,synaptic vesicle loading,and coupled transport.The other non-canonical effects of the V-ATPase that are not readily attributable to its proton-pumping activity include membrane fusion,pH sensing,amino-acid-induced activation of mTORC1,and scaffolding for protein-protein interaction.In response to various stimuli,V-ATPase complex can reversibly dissociate into V1 and V0 domains and thus close ATP-dependent proton transport.Dysregulation of pH and lysosomal dysfunction have been linked to many human diseases,including neurodegenerative disorders such as Alzheimer disease,Parkinson’s disease,amyotrophic lateral sclerosis as well as neurodegenerative lysosomal storage disorders.Conclusion V-ATPase complex is a universal proton pump and plays an important role in lysosome acidification in all types of cells.Since V-ATPase dysfunction contributes to the pathogenesis of multiple neurodegenerative diseases,further understanding the mechanisms that regulate the canonical and non-canonical functions of V-ATPase will reveal molecular details of disease process and help assess V-ATPase or molecules related to its regulation as therapeutic targets.

In vitro crevice corrosion of biodegradable magnesium in different solutions

Magnesium(Mg)is a promising biomedical metal because of its biodegradability.The crevice between tissue and Mg implant can not be neglected in some implantation sites due to inducing crevice corrosion of Mg.In this paper,a new single mold was designed to build the in vitro experimental setup and four kinds of solutions,i.e.the deionized water(DW),the 0.9 wt.%sodium chloride solution(NaCl),the phosphate buffer saline(PBS)and the modified simulated body fluid(m-SBF)were used to explore necessary factors of crevice corrosion in Mg.It was observed that crevice corrosion in Mg sheets would occur in NaCl and PBS solution under 0.2,0.5 and 0.8 mm crevice thickness.And it was found that there were two necessary factors,i.e.chloride ion and crevice dimension,in crevice corrosion.For the high-purity Mg cannulated screws,crevice corrosion could occur inside tunnel when immersed in PBS.

Development of educational attainment and gender equality in China:new evidence from the 7th National Census

This paper discusses the status and changes in educational attainment and gender inequality in education for the Chinese population based on the data from the 7th National Census of China and previous censuses since 1982.The results indicate that gender inequality in education has lessened while educational attainment has improved.However,it is necessary to continue to eradicate illiteracy in the West,further promote compulsory education rates,increase the advancement rate to high school,and reduce the urban-rural gap in education to further develop education.This paper indicates that the increased educational opportunities for women combined with their relatively superior academic abilities have resulted in a new reversed gender inequality in that males are at a disadvantage,especially in higher education.The fact that women have benefited more from the expansion of higher education than men have was an unintended consequence of China's one-child fertility policy since the family resources are less diluted by fewer children in a household and daughters are regarded as long-term family members.This paper further reveals that although women outperform men at every level of the educational system,they often voluntarily withdraw from pursuing doctoral degrees due to the increasing pressure as they age and age discrimination which drives them to enter marriage and the labor market earlier than men do.