竹节参对大强度耐力训练大鼠心肌线粒体抗氧化能力的研究

目的:探讨竹节参对大强度耐力训练大鼠心肌线粒体抗氧化能力的影响,为该药运用于抗运动疲劳提供理论依据。方法:将大鼠随机分为安静对照组,大强度耐力训练组(训练组),大强度耐力训练+竹节人参组(训练加药组),测定心肌线粒体脂质过氧化产物丙二醛(MDA)和过氧化氢(H2O2)的含量以及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)的活性,研究竹节参对大强度耐力训练大鼠心肌线粒体的保护作用。结果:力竭运动引起大鼠心肌线粒体MDA、H2O2含量显著升高(P0.01),心肌线粒体抗氧化酶CAT、GSH-Px、SOD活性显著下降(P0.01);训练加药组大鼠心肌线粒体MDA、H2O2含量明显低于训练组(P0.01),CAT、GSH-Px、SOD活性明显高于训练组。结论:竹节参可明显提高大强度耐力训练大鼠心肌线粒体的抗氧化能力,保护心肌线粒体的氧化损伤。     

慢性间断低氧暴露对大鼠心肌线粒体ATP酶及吸链酶复合物的影响

目的:研究慢性间断低氧暴露对大鼠心肌线粒体Na 、K -ATPase和Ca2 、Mg2 -ATPase以及呼吸链酶复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ活性的影响.方法:经慢性间断低氧暴露(模拟海拔3 000 m、5 000 m分别低氧,每天4 h,共2周,最后8 000 m低氧4 h)和急性低氧(模拟海拔8 000 m低氧4 h)的大鼠,断头处死,迅速取出心脏,分离心肌线粒体,用水解磷酸根法测定ATP酶活性,用Clark氧电极法测定呼吸链酶复合物的活性.结果:①慢性间断低氧暴露对大鼠心肌线粒体Na 、K -ATPase的活性无明显影响.②急性低氧大鼠心肌线粒体Ca2 、Mg2 -ATPase的活性较正常大鼠显著降低,而慢性间断低氧暴露大鼠心肌线粒体Ca2 、Mg2 -ATPase的活性则明显升高,接近正常水平.③急性低氧大鼠心肌线粒体呼吸链酶复合物I(NADH-CoQ还原酶)、复合物Ⅱ(琥珀酸-CoQ还原酶)、复合物IV(细胞色素氧化酶)活性较正常大鼠显著降低,而经慢性间断低氧暴露后,三者的活性均显著提高.相同实验条件下,低氧对复合物Ⅲ(CoQ-细胞色素C还原酶)活性无明显影响.结论:慢性间断低氧暴露可以显著提高心肌线粒体Ca2 、Mg2 -ATPase和呼吸链酶复合物Ⅰ、Ⅱ、Ⅳ的活性,从而改善低氧时心肌线粒体呼吸链的功能,维持心肌正常能量代谢,最终提高心肌收缩和舒张功能.     

硫化氢对急性心肌缺血大鼠心肌线粒体损伤的影响

目的：探讨硫化氢（H2S）对急性心肌缺血大鼠线粒体功能的影响,并探讨其改善急性心肌缺血损伤的作用机制。方法：通过结扎大鼠左冠状动脉前降支建立急性心肌缺血模型。雄性SD大鼠48只随机分为6组（n=8）：假手术组,缺血组,缺血＋硫氢化钠（NaHS）低、中、高剂量组和缺血＋炔丙基甘氨酸（PPG）组。透射电镜观察心肌组织线粒体超微结构;检测血浆中H2S含量、心肌组织CSE活性;测定心肌线粒体活力、膜肿胀度及线粒体总ATP酶、谷胱甘肽过氧化物酶（GSH-PX）、超氧化物歧化酶（SOD）的活性和丙二醛（MDA）含量。结果：与假手术组比较,缺血组大鼠血浆H2S含量和心肌组织中CSE活性降低;心肌线粒体膜肿胀,线粒体活力下降;线粒体中MDA含量明显升高,ATP酶、SOD、GSH-Px活性明显降低（P〈0.01）。与缺血组比较,缺血＋NaHS低、中、高剂量组大鼠血浆H2S含量和心组织中CSE活性均升高;缺血＋NaHS中、高剂量组大鼠心肌线粒体MDA含量明显减少,膜肿胀度减轻;缺血＋NaHS低、中、高剂量组线粒体活力有所恢复,ATP酶、SOD、GSH-Px的活性明显升高（P〈0.05或P〈0.01）。PPG可部分减弱H2S的心肌保护作用（P〈0.05或P〈0.01）。结论：H2S可增强线粒体ATP酶、SOD、GSH-Px的活性,降低线粒体脂质过氧化水平,从而起到对大鼠急性心肌缺血的保护作用。     

甘草黄酮对长期大强度运动小鼠心肌损伤的保护作用

为了探讨甘草黄酮对长期大强度运动小鼠心肌损伤的保护作用机制。本研究选用50只昆明雄性小鼠为研究对象,以每组10只分组,分为安静对照组(A组)、运动训练组(B组)、运动低剂量给药组(C组)、运动中剂量给药组(D组)、以及运动高剂量给药组(E组)。运动低剂量给药组(C组)、运动中剂量给药组(D组)、运动高剂量给药组(E组)训练前分别灌服剂量为5 g/kg/d、10 g/kg/d、15 g/kg/d黄酮溶液;除安静对照组外,运动组小鼠进行为期6周的大强度游泳训练。测定小鼠各组小鼠血清CK-MB、c Tn I,心肌组织中GSH-PX、SOD、CAT、MDA、NOS、NO、Na+/K+-ATP、Ca2+/Mg2+-ATP。结果表明:与安静对照组比较,运动训练组CK-MB、c Tn I、MDA、NO、NOS升高,GSH-PX、SOD、CAT、Na+/K+-ATP、Ca2+/Mg2+-ATP降低。与运动训练组比较,运动低剂量给药组、运动中剂量给药组、运动高剂量给药组CK-MB、c Tn I、MDA、NO、NOS降低,GSH-PX、SOD、CAT、Na+/K+-ATP、Ca2+/Mg2+-ATP升高;与运动低剂量给药组比较,运动高剂量给药组CK-MB、c Tn I、GSH-Px、SOD、Na+/K+-ATP、Ca2+/Mg2+-ATP升高,MDA降低。本研究提示,长期大强度运动导致机体心肌损伤,甘草黄酮可提高机体心肌组织中抗氧酶、ATPase酶的活性,抑制自由基生成、NOS活性,减少NO的生成,维持细胞膜内外Na+、K+、Ca2+、Mg2+的分布平衡,对大强度运动造成的心肌损伤具有保护作用,效果以高剂量黄酮最佳。     

大蒜素对大鼠骨骼肌抗氧化能力和ATP酶活性的影响

目的:探讨大蒜素对大鼠骨骼肌抗氧化能力和ATP酶活性的影响。方法:30只SD大鼠随机分为安静组、训练组、大蒜素训练组(n=10),6周训练和补充大蒜素后,测定大鼠骨骼肌超氧化物歧化酶(SOD)、丙二醛(MDA)、Ca2+-ATPase、Na+-K+-ATPase和血清Ca2+的含量。结果:大蒜素训练组与训练组相比,运动至力竭的时间明显延长;骨骼肌抗氧化能力明显升高,Na+-K+-ATPase,Ca2+-ATPase及血清Ca2+极为显著升高。结论:大蒜素能增强大鼠骨骼肌抗氧化能力,延缓疲劳出现。     

一次性力竭运动对大鼠PHB1表达及线粒体功能的影响

目的：观察一次性力竭运动后大鼠脑、心、骨骼肌组织和线粒体中PHB1含量的变化及对大鼠线粒体功能的影响,探寻PHB1与线粒体功能和能量代谢的关系。方法：健康雄性SD大鼠40只,随机分为2组（n=20）：对照组和一次性力竭运动组,大鼠进行一次性急性跑台运动建立力竭运动模型。收集各组大鼠的心、脑和骨骼肌组织样品并提取线粒体,检测其呼吸功能和ROS的变化。用Western blot方法检测组织和线粒体中PHB1蛋白表达水平;用分光光度计检测各器官中ATP含量以及线粒体中复合体V活性（ATP合酶活性）。结果：①一次性力竭运动后脑、心肌、骨骼肌中ATP含量显著性降低;②一次性力竭运动后脑、心肌、骨骼肌线粒体中复合体V活性、RCR、ROS显著性降低,ST4均显著性升高,ST3无显著性差异。③一次性力竭运动后心、脑、骨骼肌线粒体中PHB1的表达显著性减少。④通过相关性分析得出：一次性力竭运动后心、脑、骨骼肌中ATP含量与心、脑、骨骼肌中复合体V活性呈正相关;心、脑、骨骼肌中ATP含量和心、脑骨骼肌中PHB1的表达呈正相关。结论：一次性力竭运动后,降低线粒体氧化磷酸化功能,使大鼠脑、骨骼肌线粒体内ROS生成增加,PHB1的表达、ATP含量和复合体V活性均下降。一次性力竭运动使得大鼠线粒体内PHB1表达降低,线粒体功能减弱,机体能量代谢降低。     

11,12.环氧二十碳三烯酸预处理与后处理对缺血/再灌注大鼠心肌的保护作用

采用Langendorff离体灌流装置,通过停灌40 min/复灌30 min复制大鼠心肌缺血/再灌注(ischemia/reperfusion,IR)损伤模型,观察11,12-环氧二十碳三烯酸(11,12-epoxyeicosatrienoic acid,11,12-EET)预处理和后处理对心肌线粒体功能以及心功能的影响,探讨11,12-EET顸处理和后处理对IR大鼠心肌的作用及其机制.将30只Sprague-Dawley大鼠随机分为对照组、IR组、EET预处理组(Pre-EET)、EET后处理组(Post-EET),每组6只.除对照组外,其它各组全心缺血40 min,再灌注30 min.监测左心室内压差(ALVP)和左心室内压升降的最大变化率(±dp/dtmax)等心功能指标,测定灌流液中乳酸脱氢酶(1actate dehydrogenase,LDH)的活性.灌流结束后,测定心肌线粒体琥珀酸脱氢酶(succinate dehydrogenase,SDH)、Ca"ATPase、Na - K -ATPase活性以及心肌超氧化物歧化酶(superoxide dismutase,SOD)活性、丙二醛(malondialdehyde,MDA)含量.结果显示:(1)与IR组相比,Pre-EET组及Post.EET组Na -K -ATPase和SDH活性均增强,Ca2 -ATPase活性均减弱,有显著性差异(P<0.05);而Pre-EET与Post-EET组间没有显著性差异.(2)与IR组相比,Pre-EET组及Post-EET组心功能明显改善,LDH漏出显著减少,心肌SOD活性明显增强,MDA含量明显降低,有显著性差异(P<0.05);而Pre-EET与Post-EET组间没有显著性差异.结果表明,11,12-EET预处理及后处理均可通过上调心肌线粒体Na -K -ATPase、SDH活性以及下调Ca2 -ATPase活性改善线粒体功能和心肌能量代谢,拮抗心肌IR损伤;11,12-EET预处理及后处理还可通过提高心肌SOD活性、降低MDA含量改善IR心肌的氧化应激.     

缬沙坦对家兔梗死心肌MDA、SOD、ATPase活性的影响

目的：探讨缬沙坦（Valsartan,VAL）对心肌梗死（MI）作用及其作用机制。方法：结扎冠状动脉左前降支建立心肌梗死建模,随即分为假手术组、心肌梗死组、VAL组。然后分别在各组中应用BL-420F生物机能实验系统测定右颈总动脉插入动脉导管的心肌梗死（MI）的左室收缩压（LVSP）、左室舒张末压（LVEDP）;分别采用黄嘌呤氧化法和硫代巴比妥酸显色法测定心肌丙二醛（MDA）和超氧化物歧化酶（SOD）含量以及应用定磷法心肌细胞细胞膜Na＋-K＋-ATPase、Ca2＋-ATPase活性。结果：VAL可降低MI家兔的收缩压不明显（P〉0.05）,但降低舒张末降低明显（P〈0.01）;VAL使MI家兔增高的MAD显著降低（P〈0.01）;使MI家兔降低的SOD值显著恢复、增加（P〈0.01）;VAL可使MI家兔降低的Na＋-K＋-ATPase和Ca2＋-ATPase活性恢复、增加（P〈0.05）。结论：VAL可能通过稳定细胞膜抗脂质过氧化反应及提高清除氧自由基以及促进MI后心肌细胞膜Na＋-K＋-ATPase ATPase和Ca2＋-AT-Pase活性的途径改善心肌梗死（MI）作用。     

急性颅脑损伤大鼠脑组织ATP酶活性及TNF-α的变化及意义

目的 观察大鼠急性颅脑损伤后脑组织ATP酶活性及肿瘤坏死因子-α（TNF-α）的变化,探讨急性颅脑损伤后脑水肿的发病机制.方法 将72只SD大鼠随机分为正常组（N组）、假手术对照组（S组）、急性颅脑损伤模型组（ACI组）,其中S组和ACI组于造模后分为2、6、24、72 h时间点,每个时间点8只大鼠;取大鼠伤灶区脑组织测定Na＋-K＋-ATP酶和Ca2＋-ATP酶活性、TNF-α含量及脑组织含水量.结果 急性颅脑损伤后脑组织Na＋-K＋-ATP酶、Ca2＋-ATP酶活性降低（P〈0.05）,TNF-α含量升高（P〈0.05）;颅脑损伤后24 h脑水肿较严重.相关性分析提示,Ca2＋-ATP酶活性与TNF-α含量呈负相关（P〈0.05）.结论 急性颅脑损伤后可引起脑组织ATP酶活性降低、TNF-α含量增加,两者可能协同参与了急性颅脑损伤后脑水肿.     

蟾酥、蟾皮、蟾衣提取物对心肌细胞膜ATP酶的影响

用中华大蟾蜍蟾酥、蟾皮、蟾衣脂溶性及水溶性提取物研究其对小鼠心肌细胞膜Na -K -ATP酶、Ca2 -ATP酶和Mg2 -Ca2 -ATP酶活性影响,同时以华蟾素注射液为对照.结果 表明:所有提取物均可抑制心肌细胞膜的上述3种ATP酶活性,其中对Na -K -ATP酶抑制作用较强的有蟾皮脂溶性和蟾酥脂溶性成分,对Ca2 -ATP酶和对Mg2 -Ca2 -ATP酶的影响结果相类似,作用较强的有蟾皮水溶性成分和华蟾素.     

Dissecting the Heat Stress Response in Chlamydomonas by Pharmaceutical and RNAi Approaches Reveals Conserved and Novel Aspects

To study how conserved fundamental concepts of the heat stress response （HSR） are in photosynthetic eukaryotes, we applied pharmaceutical and antisense/amiRNA approaches to the unicellular green alga Chlamydomonas reinhardtii. The Chlamydomonas HSR appears to be triggered by the accumulation of unfolded proteins, as it was induced at ambient temperatures by feeding cells with the arginine analog canavanine. The protein kinase inhibitor staurosporine strongly retarded the HSR, demonstrating the importance of phosphorylation during activation of the HSR also in Chlamydomonas. While the removal of extracellular calcium by the application of EGTA and BAPTA inhibited the HSR in moss and higher plants, only the addition of BAPTA, but not of EGTA, retarded the HSR and impaired thermotoler- ance in Chlamydomonas. The addition of cycloheximide, an inhibitor of cytosolic protein synthesis, abolished the attenu- ation of the HSR, indicating that protein synthesis is necessary to restore proteostasis. HSP90 inhibitors induced a stress response when added at ambient conditions and retarded attenuation of the HSR at elevated temperatures. In addition, we detected a direct physical interaction between cytosolic HSP90A/HSP70A and heat shock factor 1, but surprisingly this interaction persisted after the onset of stress. Finally, the expression of antisense constructs targeting chloroplast HSP70B resulted in a delay of the cell＇s entire HSR, thus suggesting the existence of a retrograde stress signaling cascade that is desensitized in HSP7OB-antisense strains.     

Cell Wall,Cytoskeleton, and Cell Expansion in Higher Plants

To accommodate two seemingly contradictory biological roles in plant physiology, providing both the rigid structural support of plant cells and the adjustable elasticity needed for cell expansion, the composition of the plant cell wall has evolved to become an intricate network of cellulosic, hemicellulosic, and pectic polysaccharides and protein. Due to its complexity, many aspects of the cell wall influence plant cell expansion, and many new and insightful observations and technologies are forthcoming. The biosynthesis of cell wall polymers and the roles of the variety of proteins involved in polysaccharide synthesis continue to be characterized. The interactions within the cell wall polymer network and the modification of these interactions provide insight into how the plant cell wall provides its dual function. The complex cell wall architecture is controlled and organized in part by the dynamic intracellular cytoskeleton and by diverse trafficking pathways of the cell wall polymers and cell wall-related machinery. Meanwhile, the cell wall is continually influenced by hormonal and integrity sensing stimuli that are perceived by the cell. These many processes cooperate to construct, maintain, and manipulate the intricate plant cell wall--an essential structure for the sustaining of the plant stature, growth, and life.     

Regulation of Cytokinesis by Exocyst Subunit SEC6 and KEULE in Arabidopsis thaliana

Proper vesicle tethering and membrane fusion at the cell plate are essential for cytokinesis. Both the vesicle tethering complex exocyst and membrane fusion regulator KEULE were shown to function in cell plate formation, but the exact mechanisms still remain to be explored. In this study, using yeast two-hybrid （Y-2-H） assay, we found that SEC6 interacted with KEULE, and that a small portion of C-terminal region of KEULE was required for the interaction. The direct SEC6-KEULE interaction was supported by further studies using in vitro pull-down assay, immunoprecipitation, and in vivo bimolecular florescence complementation （BIFC） microscopy, sec6 mutants were male gametophytic lethal as reported; however, pollen-rescued sec6 mutants （PRsec6） displayed cytokinesis defects in the embryonic cells and later in the leaf pavement cells and the guard cells. SEC6 and KEULE proteins were co-localized to the cell plate during cytokine- sis in transgenic Arabidopsis. Furthermore, only SEC6 but not other exocyst subunits located in the cell plate interacted with KEULE in vitro. These results demonstrated that, like KEULE, SEC6 plays a physiological role in cytokinesis, and the SEC6-KEULE interaction may serve as a novel molecular linkage between arriving vesicles and membrane fusion machin- ery or directly regulate membrane fusion during cell plate formation in plants.     

Perturbation of Auxin Homeostasis Caused by Mitochondrial FtSH4 Gene-Mediated Peroxidase Accumulation Regulates Arabiclopsis Architecture

Reactive oxygen species and auxin play important roles in the networks that regulate plant development and morphogenetic changes, However, the molecular mechanisms underlying the interactions between them are poorly understood. This study isolated a mas （More Axillary Shoots） mutant, which was identified as an allele of the mitochondrial AAA-protease AtFtSH4, and characterized the function of the FtSH4 gene in regulating plant development by medi- ating the peroxidase-dependent interplay between hydrogen peroxide （H2Oz） and auxin homeostasis. The phenotypes of dwarfism and increased axillary branches observed in the mas （renamed as ftsh4-4） mutant result from a decrease in the IAA concentration. The expression levels of several auxin signaling genes, including IAA1, IAA2, and IAA3, as well as several auxin binding and transport genes, decreased significantly in ftsh4-4 plants. However, the H202 and peroxidases levels, which also have IAA oxidase activity, were significantly elevated in ftsh4-4 plants. The ftsh4-4 phenotypes could be reversed by expressing the iaaM gene or by knocking down the peroxidase genes PRX34 and PRX33. Both approaches can increase auxin levels in the ftsh4-4 mutant. Taken together, these results provided direct molecular and genetic evidence for the interaction between mitochondrial ATP-dependent protease, H2O2, and auxin homeostasis to regulate plant growth and development.     

Redox Regulation of Arabidopsis Mitochondrial Citrate Synthase

Citrate synthase has a key role in the tricarboxylic （TCA） cycle of mitochondria of all organisms, as it cata- lyzes the first committed step which is the fusion of a carbon-carbon bond between oxaloacetate and acetyl CoA. The regulation of TCA cycle function is especially important in plants, since mitochondrial activities have to be coordinated with photosynthesis. The posttranslational regulation of TCA cycle activity in plants is thus far almost entirely unexplored. Although several TCA cycle enzymes have been identified as thioredoxin targets in vitro, the existence of any thioredoxin-dependent regulation as known for the Calvin cycle, yet remains to be demonstrated. Here we have investigated the redox regulation of the Arabidopsis citrate synthase enzyme by site-directed mutagenesis of its six cysteine residues. Our results indicate that oxidation inhibits the enzyme activity by the formation of mixed disulfides, as the partially oxidized citrate synthase enzyme forms large redox-dependent aggregates. Furthermore, we were able to demonstrate that thioredoxin can cleave diverse intraas well as intermolecular disulfide bridges, which strongly enhances the activity of the enzyme. Activity measurements with the cysteine variants of the enzyme revealed important cysteine residues affecting total enzyme activity as well as the redox sensitivity of the enzyme.     

Genotoxicity biomarkers in aquatic bioindicators

Pollution of the aquatic environment is an ever-growing problem, as waters are the ultimate sink for the large number of xenobiotics from multiple sources. DNA damaging agents have a significant ecological relevance since they are implicated in many pathological processes and exert effects beyond that of individual being active through following generations. A large number of methods have been applied to evaluate genotoxic damage in different aquatic species. Comet assay, as method for de- tecting DNA alterations, and micronucleus test, as an index of chromosomal damage are the most widely applied and validated methods in field studies. These methods were applied in different vertebrate and invertebrate aquatic species, but only mollusk and fish species have been employed in routine biomonitoring programs. Mussels, due to their widely geographical distribution and the suitability for caging represent the bioindicator of choice in field studies. Mytilus species is the most used marine mussel. The use of fish is limited to specific geographic areas. The present review mainly focuses on the application of comet assay and micronucleus test in mussels. A number of biomonitoring studies in mussels, using comet assay or micronucleus test, revealed exposure to different classes of genotoxic compounds with a good discrimination power. The different evidence from the two as- says, reflects different biological mechanisms for the two genetic endpoints, DNA damage and chromosomal damage, suggesting their combined application in the field. Different endogenous and exogenous factors have been shown to modulate the genotoxic responses in mussels, acting as confounding factors in environmental monitoring. The use of standardized protocol for caging, sampling and genotoxity evaluation is critical in biomonitoring studies. The use of a multimarker approach coupling genotoxicity biomarkers with physiological and biochemical factors allows to have a complete picture of the environmental pollution [Current Zoology 60 （2）： 273-284, 2014].     

Salt Stress in Arabidopsis： Lipid Transfer Protein AZI1 and Its Control by Mitogen-Activated Protein Kinase MPK3

A plant＇s capability to cope with environmental challenges largely relies on signal transmission through mitogen-activated protein kinase （MAPK） cascades. In Arabidopsis thaliana, MPK3 is particularly strongly associated with numerous abiotic and biotic stress responses. Identification of MPK3 substrates is a milestone towards improving stress resistance in plants. Here, we characterize AZI1, a lipid transfer protein （LTP）-related hybrid proline-rich protein （HyPRP）, as a novel target of MPK3. AZI1 is phosphorylated by MPK3 in vitro. As documented by co-immunoprecipitation and bimolecular fluorescence complementation experiments, AZI1 interacts with MPK3 to form protein complexes in planta. Furthermore, null mutants of azil are hypersensitive to salt stress, while AZIl-overexpressing lines are markedly more tolerant. AZI1 overexpression in the mpk3 genetic background partially alleviates the salt-hypersensitive phenotype of this mutant, but functional MPK3 appears to be required for the full extent of AZIl-conferred robustness. Notably, this robustness does not come at the expense of normal development. Immunoblot and RT-PCR data point to a role of MPK3 as positive regulator of AZI1 abundance.     

Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes

Herbivorous insects frequently harbor bacterial symbionts that affect their ecol- ogy and evolution. Aphids host the obligatory endosymbiont Buchnera, which is requiredfor reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularlystudied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species （not counting Buchnera） having environmentally dependent effects on host fitness.In particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionallytransferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondarysymbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigatedinheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic generations.We found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species （Serratia symbiotica）was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid.