白化黑线仓鼠的遗传学研究──I、异构蛋白及同工酶醋纤膜电泳结果观察

利用生化电泳技术对白化黑线仓鼠、驯育中的黑线仓鼠、野牛黑线仓鼠的九种异构蛋白及同工酶进行了醋酸纤维素膜电泳，以观察它们在生化基因位点上有何差别及基因频率分布。结果表明，这三种类型的黑线仓鼠电泳带型单一，看不出像小鼠那样有两种或两种以上的多态性，且电泳迁移率完全一致。从生化标记基因方面提供了该动物基因单一性的又一证据．

鳜肌钙蛋白基因鉴定及其序列结构与表达特征分析

【目的】探究鳜(Siniperca chuatsi)骨骼肌生长发育中肌钙蛋白基因的表达特征,为鳜生长发育的研究提供基础资料。【方法】基于鳜转录组数据与基因组数据联合分析,筛选鉴定出鳜肌钙蛋白基因,通过BioEdit、ClustalW、MEGA5.0、SWISS-MODEL及SMART等在线软件对鳜肌钙蛋白进行生物信息学分析,并以实时荧光定量PCR检测鳜不同肌肉组织中肌钙蛋白基因的表达特异及孵化后10~60 d(10~60 dph)骨骼肌中肌钙蛋白基因的表达规律。【结果】共鉴定出11个鳜肌钙蛋白基因[3个TnnC基因(TnnC1a、TnnC1b和TnnC2)、5个TnnI基因(TnnI1a、TnnI1b、TnnI1c、TnnI1al和TnnI2)及3个TnnT基因(TnnT1、TnnT2a和TnnT3a)],各基因亚型间在基因结构、结合位点及蛋白三级结构存在明显差异,11个鳜肌钙蛋白基因分布在4条染色体上。鳜肌钙蛋白基因具有组织特异性:TnnC1a基因在慢肌中高表达,在心肌中的相对表达量次之;TnnC1b基因在慢肌中也呈高表达,除心肌外,TnnC1a和TnnC1b基因在其他类型肌肉组织中具有相似的表达模式;TnnC2基因在快肌和颊肌中高表达;TnnI1a、TnnI1c和TnnI1al基因在慢肌中高表达,且具有相似的表达模式;TnnI1b基因在心肌中高表达,慢肌中的相对表达量次之;TnnI2基因在快肌和颊肌中高表达;TnnT1基因在慢肌中高表达,TnnT2a基因在心肌中高表达,TnnT3a基因在快肌和颊肌中高表达。随着发育时间的推移,TnnC1a、TnnC1b、TnnI1b、TnnI1c、TnnI1al和TnnT1等基因的表达显著下调(P<0.05),但TnnC2、TnnI2和TnnT3a基因在30~60 dph仍维持在相对较高的表达水平。【结论】基于鳜转录组数据与基因组数据联合分析,共鉴定出11个鳜肌钙蛋白基因,其中TnnC2、TnnI2和TnnT3a基因可作为鳜骨骼肌快肌生长发育的重要分子标记基因。

稻谷人工老化后种胚异构天冬氨酸动态监测与总蛋白差异表达分析

蛋白质中天冬氨酸和天冬酰胺自发形成的异构天冬氨酸残基是组织细胞中常见的蛋白质共价损伤.在前人的研究中,PIMT1介导的种子寿命提高,很可能是由于修复了种胚中因老化处理而过量累积的含异构天冬氨酸(isoaspartyl,isoAsp)蛋白,维持了种胚的活性.然而,异构天冬氨酸蛋白甲基转移酶(protein L-isoaspartyl methyltransferase,PIMT)对于水稻种子活力的作用机制,仍然不甚明确.本研究利用RNAi干扰技术获得了稳定的OsPIMT1的低表达株系.种子经人工老化后,结果表明OsPIMT1的低表达影响种子发芽活力.随后对种胚中含异构天冬氨酸的蛋白进行动态检测,结果显示在未吸胀和吸胀过后的种子中,种胚中的OsPIMT1的表达都能降低isoAsp的累积.而RNAi株系中OsPIMT1的低表达导致isoAsp的过度积累,进而影响种子活力.同时利用老化5 d后的水稻种胚蛋白进行双向电泳,分析RNAi干扰种子老化过程中异构天冬氨酸过度积累对于种胚蛋白的影响,鉴定到与种子老化相关的氧化胁迫相关蛋白、糖酵解以及热激蛋白分子伴侣等蛋白.为进一步研究OsPIMT1表达对于种子老化后细胞各代谢途径的影响奠定了基础.

Bioinformatics Analysis and Homology Modeling Study of Protein Disulfide Isomerase(mPDI) from Medicago sativa L.

pdi gene from Medicago sativa L. ,encoding Protein Disulfide Isomerase（ mPDI ）, has been cloned and sequenced. According to the mRNA and amino acid sequence, the character of mPDI such as the physical and chemical properties, hydrophilicity/hydrophobicity, signal peptide, secondary structure, coiled coil, transmembrane domains, O-glycogylation site, active site, subcellular localization, functional structural domains and three-dimensional structure were analyzed by a series of bioinformatics software. The results showed that mPDI was a hydrophobic and stable protein with 3 coiled coils, 30-glycogylation sites, 2 structural domains of thioredoxin, 2 active sites of thioredoxin, and located in rough endoplasmic reticulum. It has 512 amino acids, the theoretical pl is 4.98, and signal peptide located in 1-24AA. In the secondary structure, a-helix, random coil, extended chain is 26.37%, 53.32%, 20.31% respectively. The validation of modeling accords with the stereochemistry.

Expression and Identification of Inclusion Forming-related Domain of NS80 Nonstructural Protein of Grass Carp Reovirus

Grass carp reovirus （GCRV）, a double stranded RNA virus that infects aquatic animals, often with disastrous effects, belongs to the genus Aquareovirus and family Reoviridea. Similar to other reoviruses, genome replication of GCRV in infected cells occurs in cytoplasmic inclusion bodies, also called viral factories. Sequences analysis revealed the nonstmctural protein NS80, encoded by GCRV segment 4, has a high similarity with μNS in MRV（Mammalian orthoreovimses）, which may be associated with viral factory formation. To understand the function of the μNS80 protein in virus replication, the initial expression and identification of the immunogenicity of the GCRV NS80 protein inclusion forming-related region （335-742） was investigated in this study. It is shown that the over-expressed fusion protein was produced by inducing with IPTG at 28℃. In addition, serum specific rabbit antibody was obtained by using super purified recombinant NS80（335-742） protein as antigen. Moreover, the expressed protein was able to bind to anti-his-tag monoclonal antibody （mouse） and NS80〈335.742） specific rabbit antibody. Further western blot analysis indicates that the antiserum could detect NS80 or NS80C protein expression in GCRV infected cells. This data provides a foundation for further investigation of the role of NS80 in viral inclusion formation and virion assembly.

Structural insights into a dual-specificity histone demethylase ceKDM7A from Caenorhabditis elegans

Histone lysine methylation can be removed by JmjC domain-containing proteins in a sequence- and methylationstate-specific manner. However, how substrate specificity is determined and how the enzymes are regulated were largely unknown. We recently found that ceKDM7A, a PHD- and JmjC domain-containing protein, is a histone demethylase specific for H3K9me2 and H3K27me2, and the PHD finger binding to H3K4me3 guides the demethylation activity in vivo. To provide structural insight into the molecular mechanisms for the enzymatic activity and the function of the PHD finger, we solved six crystal structures of the enzyme in apo form and in complex with single or two peptides containing various combinations of H3K4me3, H3K9me2, and H3K27me2 modifications. The structures indicate that H3Kgme2 and H3K27me2 interact with ceKDMTA in a similar fashion, and that the peptide-binding specificity is determined by a network of specific interactions. The geometrical measurement of the structures also revealed that H3K4me3 associated with the PHD finger and H3K9me2 bound to the JmjC domain are from two separate molecules, suggesting a trans-histone peptide-binding mechanism. Thus, our systemic structural studies reveal not only the substrate recognition by the catalytic domain but also more importantly, the molecular mechanism of dual specifieity of ceDKM7A for both H3K9me2 and H3K27me2.

Secondary Structure and Neurotrophic Effect of a 33.1 kDa Specific Protein (SSP-33.1) in Spinal Sensory Ganglia

Aim To analyze the secondary structure and neurotrophic effect of a specific protein in sensory neurons. Methods Comparison of the proteins expressed in the rat spinal sensory neurons and motor neurons was made by two dimensional electrophoresis. One specific protein in sensory neurons was isolated and purified by DEAE Sephacel ion exchange chromatography and high performance liquid chromatography. A primary analysis of its secondary structure by circular dichroism, and its neurotrophic effects were investigated using the model of dorsal root ganglia(DRG) cultured in vitro . Results The molecular weight and isoelectric point of the protein were 33 1 kDa and 5 52, respectively. Its circular dichroism showed that there were 20 8% α helix, 54 8% β sheet, 7 3% turn, and 17 1% random coil in its secondary structure. Biological experiments showed that the protein could promote the neurite outgrowth of DRG. Conclusion A specific protein in spinal sensory tissue with molecular weight of 33 1 kDa has been purified. There is mainly β sheet in the secondary structure of the protein. And the protein has neurotrophic effects in the model of DRG.

Engineering the heterogeneous interfaces of inverse opals to boost charge transfer for efficient solar water splitting

Herein,we report a three-dimensional porous TiO_(2)/Fe_(2)TiO_(5)/Fe_(2)O_(3)(TFF)inverse opal through in situ thermal solid reactions for photoelectrochemical water splitting.The Fe_(2)TiO_(5) interfacial layer within TFF acting as a bridge to tightly connect to TiO_(2) and Fe_(2)O_(3) reduces the interfacial charge transfer resistance,and suppresses the bulk carrier recombination.The optimized TFF displays a remarkable photocurrent density of 0.54mAcm^(-2) at 1.23V vs.reversible hydrogen electrode(RHE),which is 25 times higher than that of TiO_(2)/Fe_(2)O_(3)(TF)inverse opal(0.02mAcm^(-2) at 1.23V vs.RHE).The charge transfer rate in TFF inverse opal is 2-8 times higher than that of TF in the potential range of 0.7-1.5V vs.RHE.The effects of the Fe_(2)TiO_(5) interfacial layer are further revealed by X-ray absorption spectroscopy and intensity-modulated photocurrent spectroscopy.This work offers an interfacial engineering protocol to improve charge separation and transfer for efficient solar water splitting.

Phylogenetic analysis revealed the central roles of two African countries in the evolution and worldwide spread of Zika virus

Recent outbreaks of Zika virus （ZIKV） infections in Oceania＇s islands and the Americas were characterized by high numbers of cases and the spread of the virus to new areas. To better understand the origin of ZIKV, its epidemic history was reviewed. Although the available records and information are limited, two major genetic lineages of ZIKV were identified in previous studies. However, in this study, three lineages were identified based on a phylogenetic analysis of all virus sequences from GenBank, including those of the envelope protein （E） and non-structural protein 5 （NS5） coding regions. The spatial and temporal distributions of the three identified ZIKV lineages and the recombination events and mechanisms underlying their divergence and evolution were further elaborated. The potential migration pathway of ZIKV was also characterized. Our findings revealed the central roles of two African countries, Senegal and Cote d＇lvoire, in ZIKV evolution and genotypic divergence. Furthermore, our results suggested that the outbreaks in Asia and the Pacific islands originated from Africa. The results provide insights into the geographic origins of ZlKV outbreaks and the spread of the virus, and also contribute to a better understanding of ZlKV evolution, which is important for the prevention and control of ZlKV infections.

Heterologous interactions between NS1 proteins from different influenza A virus subtypes/strains

Non-structural protein 1 （NS1） of the influenza virus plays a crucial role in modulating the host immune response and facili- tating virus replication. The formation of a homodimer or an oligomer is necessary for NSI to exert its function efficiently. In the present study, the NS 1 protein from the A/Shantou/602/06（H3N2） virus （herein abbreviated as NS32） was found to interact with NS1 from A/Shantou/169/O6（H1N1）, A/Chicken/Guangdong/1/05（HSN1） and A/Quail/Hong Kong/G1/97（H9N2） （abbre- viated as NS11, NS51 and NS92, respectively） viruses, although NS32 shares 17.4%-20.9% sequence diversity with NS11, NS51 and NS92. This indicates that the heterologous interactions between NS1 proteins from different influenza A virus sub- types/strains may be a common event during co-infection.