Mitochondrial genome sequences of Artemia tibetiana and Artemia urmiana: assessing molecular changes for high plateau adaptation

Brine shrimps,Artemia(Crustacea,Anostraca),inhabit hypersaline environments and have a broad geographical distribution from sea level to high plateaus.Artemia therefore possess significant genetic diversity,which gives them their outstanding adaptability.To understand this remarkable plasticity,we sequenced the mitochondrial genomes of two Artemia tibetiana isolates from the Tibetan Plateau in China and one Artemia urmiana isolate from Lake Urmia in Iran and compared them with the genome of a low-altitude Artemia,A.franciscana.We compared the ratio of the rate of nonsynonymous(Ka) and synonymous(Ks) substitutions(Ka/Ks ratio) in the mitochondrial protein-coding gene sequences and found that atp8 had the highest Ka/Ks ratios in comparisons of A.franciscana with either A.tibetiana or A.urmiana and that atp6 had the highest Ka/Ks ratio between A.tibetiana and A.urmiana.Atp6 may have experienced strong selective pressure for high-altitude adaptation because although A.tibetiana and A.urmiana are closely related they live at different altitudes.We identified two extended termination-associated sequences and three conserved sequence blocks in the D-loop region of the mitochondrial genomes.We propose that sequence variations in the D-loop region and in the subunits of the respiratory chain complexes independently or collectively contribute to the adaptation of Artemia to different altitudes.     

Structural and biochemical insights into the homotypic PB1-PB1 complex between PKCζ and p62

The atypical PKC isoforms(ζandι)play essential roles in regulating various cellular processes.Both the hetero-interaction between PKCζand p62 through their N-terminal PB1 domains and the homo-oligomerization of p62 via its PB1 domain are critical for the activation of NF-B signaling;however,the molecular mechanisms concerning the formation and regulation of these homotypic complexes remain unclear.Here we determined the crystal structure of PKCζ-PB1 in complex with a monomeric p62-PB1 mutant,where the massive electrostatic interactions between the acidic OPCA motif of PKCζ-PB1 and the basic surface of p62-PB1,as well as additional hydrogen bonds,ensure the formation of a stable and specific complex.The PKCζ-p62 interaction is interfered with the modification of a specific Cys of PKCζby the antiarthritis drug aurothiomalate,though all four cysteine residues in the PKCζ-PB1 domain can be modified in in vitro assay.In addition,detailed structural and biochemical analyses demonstrate that the PB1 domains of aPKCs belong to the type I group,which can depolymerize the high-molecular-weight p62 aggregates into homo-oligomers of lower order.These data together unravel the molecular mechanisms of the homo-or hetero-interactions between p62 and PKCζand provide the basis for designing inhibitors of NF-B signaling.     

CAPE promotes the expansion of human umbilical cord blood-derived hematopoietic stem and progenitor cells in vitro

Due to the low number of collectable stem cells from single umbilical cord blood(UCB)unit,their initial uses were limited to pediatric therapies.Clinical applications of UCB hematopoietic stem and progenitor cells(HSPCs)would become feasible if there were a culture method that can effectively expand HSPCs while maintaining their self-renewal capacity.In recent years,numerous attempts have been made to expand human UCB HSPCs in vitro.In this study,we report that caffeic acid phenethyl ester(CAPE),a small molecule from honeybee extract,can promote in vitro expansion of HSPCs.Treatment with CAPE increased the percentage of HSPCs in cultured mononuclear cells.Importantly,culture of CD34+HSPCs with CAPE resulted in a significant increase in total colony-forming units and high proliferative potential colony-forming units.Burst-forming unit-erythroid was the mostly affected colony type,which increased more than 3.7-fold in 1μg mL 1CAPE treatment group when compared to the controls.CAPE appears to induce HSPC expansion by upregulating the expression of SCF and HIF1-α.Our data suggest that CAPE may become a potent medium supplement for in vitro HSPC expansion.     

Tissue engineered esophagus by copper——small intestinal submucosa graft for esophageal repair in a canine model

Acellular porcine small intestinal submucosa(SIS)has been used for esophagoplasty with success in a canine model.However,it did not lead to complete epithelialization.For better reconstruction,a cellular component is required.Moreover,promotion of angiogenesis with copper has been widely recognized by basic research as well as clinical studies.In this study,we have evaluated the feasibility and effectiveness of combined Cu and SIS(SIS-Cu patch)for the esophageal repair using a canine model.Eighteen male beagle dogs were subjected to surgical resection to produce cervical esophageal defects(5 cm in length,180°in range).SIS with Cu(5 or 25μmol L 1copper)or without Cu was patched on the esophageal defects.Barium esophagram and histology exam were carried out to evaluate the effectiveness of the therapy.As shown,the SIS-Cu graft promoted re-epithelialization,re-vascularization and muscular regeneration.SIS-Cu patch is more effective than SIS alone for esophageal repair,and the SIS+25μmol L 1Cu group demonstrated additional advantages over the SIS+5μmol L 1Cu.     

利用全细胞膜片钳技术记录大鼠脑片NMDA电流的研究*

目的: 采用全细胞膜片钳技术记录大鼠脑片实验中NMDA电流,并介绍诱发NMDA电流的自制刺激电极制作方法。方法: 在大鼠目标脑区快速取材并获取活性良好的脑片,分别通过含受体激动剂NMDA的孵育液灌流和电刺激诱发NMDA电流两种方式进行膜片钳记录;利用针灸针自制刺激电极。结果: 通过记录到大鼠脑片神经元的EPSC和AP可判断神经元的状态,比较两种方法诱导的NMDA电流幅度,即直接灌流受体激动剂NMDA(282.0±24.3) pA和自制刺激电极诱发(261.4±40.1)pA,二者电流幅度无明显差异(P＞0.05,n=4);自制刺激电极与进口刺激电极诱发的NMDA电流幅度分别为(267.2±36.5)pA vs (239.2±41.0)pA,二者电流幅度无明显差异(P＞0.05,n=4),证明自制刺激电极成功。结论: 大鼠脑片实验中,通过直接灌流激动剂与电刺激两种方式均可诱导NMDA电流,自制刺激电极为在脑片上记录诱发电流提供了一种经济、可靠的实验手段,便于各实验室应用。     

超高产夏玉米田土壤微生物与土壤酶的动态变化

为揭示超高产夏玉米田（产量>15 000 kg·hm^-2）土壤微生物与土壤酶活性动态变化特性,在国家玉米工程技术研究中心（山东）试验场进行夏玉米生长季农田土壤微生物与土壤酶活性研究. 在连续3年产量15 000 kg·hm^-2以上的超高产夏玉米田中选择一块超高产田（HF, 产量为20 322 kg·hm^-2）与常规生产田（CF, 产量为8920.1 kg·hm^-2）进行对比分析,主要测定0～20 cm土层土壤细菌、真菌与放线菌数量及脲酶和转化酶活性. 结果表明：播种后超高产田与常规生产田土壤微生物（细菌、真菌与放线菌）数量均表现出先升高后下降的趋势,超高产田在玉米生长后期土壤微生物数量低于常规生产田,细菌与放线菌表现尤其明显,收获期超高产田B/F值（细菌与真菌数量比）比播种期高2.03倍,比常规生产田高3.02倍,常规生产田收获期与播种期的B/F值变化不显著;超高产田土壤脲酶活性在播种31 d（拔节期）后低于常规生产田,转化酶活性播种58 d（开花期）后快速下降,低于常规生产田.     

重度抑郁症发病机制相关基因的生物信息学分析

本文旨在采用生物信息学方法筛选重度抑郁症发病机制相关基因。以美国国家生物技术信息中心(NCBI)网站GEO公共数据库中GSE98793芯片数据为研究对象,用R语言limma包筛选出116个差异表达基因(differentially expressed genes,DEGs),其中上调基因66个,下调基因50个。Gene Ontology(GO)基因功能注释分析结果显示,DEGs主要分布于线粒体内膜、线粒体内,参与铜离子结合、半胱氨酸肽链内切酶活性、白细胞介素-1的细胞应答、蛋白质加工等生物过程。KEGG通路富集分析结果显示,DEGs主要富集于氧化磷酸化反应、帕金森病、非酒精性脂肪肝病、阿尔茨海默病和亨廷顿氏舞蹈病等发病机制。蛋白质相互作用网络分析结果显示,54个DEGs编码的蛋白之间存在相互作用。结合上述多种方法的分析结果,UQCRC1、GZMB、NDUFB9、NSF、SLC17A5、CTSH、NDUFB10、UQCR10、ATOX1、CST7和CTSW共11个关键基因被筛选出来,可作为诊断和治疗重度抑郁症的候选基因。综上,本研究通过对重度抑郁症芯片及其DEGs进行深入分析得到关键基因,为揭示抑郁症的分子机制和临床靶向治疗提供了重要的线索。     

硅对生姜叶片水、二氧化碳交换特性的影响

为探讨硅对生姜植株的生理效应,以莱芜大姜为试材,研究了水培营养液中不同硅素水平对生姜植株生长、硅含量及叶片光合作用和蒸腾作用的影响.结果表明：植株各器官硅含量及生物量均随营养液硅素水平的升高而显著增加,1.0 (T₁)、1.5 (T₂)、2.0 (T₃) mmol·L^-1硅(Si)处理植株叶片硅 (SiO₂) 含量分别比CK增加604.4%、834.8%和1130.4%,单株生物量分别比CK增加9.4%、19.4%和22.8%.随着硅素水平的升高,叶片Mg²⁺ TPase、Ca²⁺ ATPase活性及光合速率(P_n)和水分利用效率(WUE)提高,蒸腾速率(T_r)降低.一天中在11:00时,T₁、T₂、T₃处理的生姜叶片P_n和WUE分别比CK提高11.2%、21.8%、28.2%和23.1%、55.9%、54.8%,T_r分别比CK降低6.3%、17.1%和19.2%.此外,硅素还显著提高了生姜叶片光合作用饱和光强、CO2羧化效率及类胡萝卜素含量,但对叶绿素含量无显著影响.本试验条件下,以15～20 mmol·L-1硅素(Si)处理效果最好.     

Calls of the Large Odorous Frog(Odorrana graminea)Show Nonlinear and Individual Characteristics

Male large odorous frogs(Odorrana graminea)have been shown to have a rich vocal repertoire and their calls contain harmonics that extend into the ultrasonic range,much like calls of male O.tormota,a sympatric species.Whereas vocalizations of male O.tormota exhibit nonlinear characteristics and contain individual signatures,it is unclear whether or not those of O.graminea do.We carried out an extensive study of the vocalizations of male O.graminea with the goal of investigating whether they:(1)contained nonlinear phenomena(NLP),(2)carried individual signatures.We recorded and analyzed 1770 vocal calls from nine males.Their calls were classifiable into two distinct categories(one-note calls and multi-note calls).Of these,one-note complex/steep-frequency modulation call was the most abundant call-type.These calls showed diverse frequency modulation patterns,and abundant presence of NLP.Various basic spectral and temporal pa ra meters of such calls were individually distinct.Kruskal-Wallis Analysis of Rank test showed that the calls from individual males differed significantly.Subsequent discriminant function analysis(DFA)showed that 54.7%of the calls could be correctly assigned to individual.These results suggested that male O.graminea might be able to discriminate neighboring frogs from strangers acoustically.However,further research is necessary to demonstrate this capacity behaviorally.