EAG and behavioral responses of workers of the red imported fire ant,Solenopsis invicta Buren (Hymenoptera: Formicidae) to its trail pheromones

[目的]测定红火蚊Solenopsis invicta Buren工蚊对其跟踪信息素的触角电位(EAG)及行为反应.[方法]解剖红火蚁工蚁的杜氏腺,用正己烷溶剂提取其分泌的跟踪信息素进行气相色谱-质谱(GC-MS)分析,并测定了红火蚁工蚁对杜氏腺提取物、工蚁提取物和合成的法尼烯混合物的EAG和招募行为反应.[结果]通过与合成的法尼烯混合物的气相色谱(GC)保留时间和质谱图比对,发现杜氏腺提取物的主要成分并不是Z,E-α-法尼烯.EAG测定结果表明,红火蚁工蚁对杜氏腺提取物、工蚁提取物及100 μg的法尼烯混合物均有较强的EAG反应,其次为10μg和1 μg的法尼烯混合物.在招募行为测定中,杜氏腺提取物和工蚁提取物招募作用明显,而10,1,0.1和0.01 μg法尼烯混合物的作用均不显著.[结论]Z,E-α-法尼烯不是红火蚁跟踪信息素的主要成分;红火蚁工蚁对杜氏腺提取物、工蚁提取物有较强的EAG反应和明显的招募行为反应.     

布氏田鼠雄性的优势地位

在实验条件下对雄性成年布氏田鼠（Microtus brandti）相遇后的优势地位及生理指标的研究结果表明：布氏田鼠雄性之间存在严格的等级关系;优势雄鼠生理指标中睾丸重量和血清睾酮激素含量高于从属雄鼠,而血清中皮质醇激素的含量低于从属雄鼠。优势雄鼠的探究、攻击和修饰等行为频次显著高于从属雄鼠,而从属雄鼠在跳跃频次上多于优势雄鼠。随着观察时间的延长,不论优势个体还是从属个体,其探究频次都呈现明显的下降趋势,其他行为的频次则没有显著差异。相关性检验说明,除攻击行为可以作为判断区分雄鼠等级的依据之外,修饰行为也可以作为判断的依据。     

雄性布氏田鼠包皮腺中的昆虫信息素类似物编码的性别和个体信息

我们利用二氯甲烷抽提和气质联用(GC-MS)比较分析了正常和阉割布氏田鼠的包皮腺分泌物(PGS)成分。我们检测到33个成分,它们几乎在所有的被测布氏田鼠都存在,其中27个成分以前报道为昆虫的信息素组分。睾丸切除不能使任何一个成分完全消失,但是显著降低了10个首先从GC-MS流失出的小分子成分,即7个饱和与不饱和的乙酸酯,一个饱和六酸酯和两个饱和八酸酯,其中,包括PGS含量最高的成分E,E-法尼醇乙酸酯。因此,可以认为这些受睾丸调节的成分为雄性信息素的候选成分。对雌鼠的嗅觉双项选择测定说明低浓度的PGS和法尼醇乙酸酯水溶液对雌性有吸引作用,而高浓度时都具有趋避作用。这说明PGS具有剂量依赖的性吸引作用,法尼醇乙酸酯是一种剂量依赖的雄性信息素。进一步的数量比较说明,所有检测到成分的百分组成在个体间表现出巨大的个体变异,说明PGS的成分有个体的特异性,可能传递个体的嗅觉信息。     

植物气味化合物与斜纹夜蛾性信息素的协同作用

为提高现有性信息素对雄蛾的引诱活性, 本研究通过大量的田间试验探索植物气味化合物与斜纹夜蛾Spodoptera litura性信息素（顺9, 反11-十四碳二烯乙酸酯∶顺9, 反12-十四碳二烯乙酸酯=10∶1）的协同作用机制。从斜纹夜蛾寄主植物和花的气味化合物中, 选择9种有代表性的化合物, 并以一定剂量分别加入到斜纹夜蛾性信息素诱芯中, 在田间测试对雄蛾的引诱活性。结果表明: 在测试的9种植源性化合物中, 发现一定剂量(每个诱芯加入0.4 mg)的苯乙醛(PAA), 具有显著提高斜纹夜蛾性信息素的引诱作用, 而高剂量的苯乙醛则强烈抑制性信息素的引诱活性; 此外, 其他各种浓度的测试化合物或混合物对性信息素则没有统计上显著的增效作用。不同剂量的苯乙醛单个化合物及各种植物气味化合物组成的混合物对斜纹夜蛾也有微弱的引诱作用。苯乙醛必须要与性信息素的完整组分(以10∶1比例混合的顺9, 反11-十四碳二烯乙酸酯和顺9反, 12-十四碳二烯乙酸酯)混合才能起作用, 缺少顺9, 反12-十四碳二烯乙酸酯则没有引诱活性。本研究证明, 苯乙醛作为理想的性信息素诱芯增效剂, 可应用于建立更理想的斜纹夜蛾性信息素诱杀技术, 对性诱害虫防治和测报具有应用价值。     

不同社群条件下雄性布氏田鼠的行为

实验室内观察了布氏田鼠雄性个体之间在3 种不同社群条件下(社群1:2 只雄鼠;社群2:2 只雄鼠与1只非动情雌鼠,社群3:2 只雄鼠与1 只动情雌鼠)的相互行为,结果显示:(1)在嗅闻行为上,不论优势雄鼠还是从属雄鼠在3 组间都存在显著差异,它们的嗅闻频次都是在社群3 中最少、在社群2中居中,在社群1中嗅闻频次最多;(2)在攻击行为频次上,不论是优势雄鼠还是从属雄鼠在3 组中都不存在显著差异;(3)在上跳频次上,优势雄鼠在各组间存在显著差异,从属雄鼠在各组间不存在显著差异; (4) 在自我修饰行为频次上,不论是优势雄鼠还是从属雄鼠,在3 组之间不存在显著差异;(5)在相互友好行为上,3 组间存在显著差异。其中社群2 中的雄性之间的友好行为频次最高,社群3 中次之,社群1 中最低。结果表明,雄性之间的攻击行为并不因为雌性的存在而增强,反而会可能减少,我们推测这可能因为雄性要花费更多的时间用于社群探究和交配,从而减少了雄性之间的斗争。     

红火蚁工蚁对跟踪信息素的触角电位和行为反应

【目的】测定红火蚁Solenopsis invicta Buren工蚁对其跟踪信息素的触角电位（EAG）及行为反应。【方法】解剖红火蚁工蚁的杜氏腺, 用正己烷溶剂提取其分泌的跟踪信息素进行气相色谱-质谱（GC-MS）分析, 并测定了红火蚁工蚁对杜氏腺提取物、 工蚁提取物和合成的法尼烯混合物的EAG和招募行为反应。【结果】通过与合成的法尼烯混合物的气相色谱（GC）保留时间和质谱图比对, 发现杜氏腺提取物的主要成分并不是Z, E-α-法尼烯。EAG测定结果表明, 红火蚁工蚁对杜氏腺提取物、 工蚁提取物及100 μg的法尼烯混合物均有较强的EAG反应, 其次为10 μg和1 μg的法尼烯混合物。在招募行为测定中, 杜氏腺提取物和工蚁提取物招募作用明显, 而10, 1, 0.1和0.01 μg法尼烯混合物的作用均不显著。【结论】Z, E-α-法尼烯不是红火蚁跟踪信息素的主要成分; 红火蚁工蚁对杜氏腺提取物、 工蚁提取物有较强的EAG反应和明显的招募行为反应。     

黄杨绢野螟雌蛾性信息素的鉴定及诱蛾活性

【目的】研究旨在深入探讨中国黄杨绢野Diaphania perspectalis 的雌蛾性信息素组成及诱蛾活性。【方法】利用气质联用仪（GC-MS）对黄杨绢野螟正常型性成熟雌蛾的性腺体提取物和合成标样比较分析,并用反-11-十六碳烯醛(E11-16:Ald) 、顺-11-十六碳烯醛（Z-11-16:Ald）、顺-9-十六碳烯醛（Z-9-16:Ald)、顺-11-十六碳烯醇（Z-11-16:OH)等物质进行触角的电生理测定,最后开展田间诱集比较试验以筛选出最佳性信息素混合物。【结果】Z-11-16:Ald为中国黄杨绢野螟正常型性信息素主要组分,E-11-16:Ald的含量极低,Z-11-16:OH未检测到。正常型雄性黄杨绢野螟触角对Z-11-16:Ald, E-11-16:Ald, Z-9-16:Ald和Z-11-16:OH产生强烈的EAG反应,并随着浓度的提高而显著增加;而对Z-11-16:Ac和E-11-16:Ac的嗅觉反应较弱,低于对植物绿叶气味顺3-己烯乙酸酯（Z-3-6:Ac）的反应。单一Z-1-16:Ald对正常型雄性黄杨绢野螟具有强烈的诱集效果,加入E-11-16:Ald有一定的增效作用,但在统计上则不显著。单一Z-11-16:Ald组分对黑化型雄性黄杨绢野螟无引诱活性,必需加入一定比例的E-11-16:Ald才显示诱蛾活性。Z-11-16:Ald:E-11-16:Ald的比例为250 μg:250 μg时诱集到的黑化型雄性黄杨绢野螟数量最多,而Z-11-16:Ald:E-11-16:Ald的比例为429 μg:71 μg时则诱集到的正常型雄性黄杨绢野螟数量最多。同时,单一Z-11-16:Ald也可引诱大量雄性粘虫Mythimna separata,但E-11-16:Ald抑制其活性。【结论】中国黄杨绢野螟的性信息素主成分是Z-11-16:Ald,单一组分即可在田间强烈引诱雄蛾,E-11-16:Ald的功能只起到微弱的增效作用,但也可能起种的专一性的作用。正常型与黑化型黄杨绢野螟对性信息素的嗅觉反应存在差异,黑化型黄杨绢野螟的性信息素接近日本种,即性信息素组成为Z-11-16:Ald和E-11-16:Ald 的混合物,其比例为1:1,且E-11-16:Ald为必需。     

棉铃虫和烟青虫性信息素腺体脂肪醇和乙酸酯转化的比较研究

棉铃虫Helicoverpa armigera和烟青虫H. assulta属于可同域发生的近缘种昆虫,通过产生比例相反的两种性信息素化合物——顺9-十六碳烯醛和顺11-十六碳烯醛维持种间生殖隔离。本研究应用外源不饱和脂肪醇及乙酸酯在棉铃虫和烟青虫性信息素腺体进行在体转化,利用气相色谱法分析转化产物,从酶学角度探讨了上述两近缘种昆虫性信息素腺体组分差异的形成原因。实验结果表明,两种昆虫信息素腺体表皮伯醇氧化酶对外源顺9-十六碳烯醇、顺11-十六碳烯醇和反10-十六碳烯醇无催化专一性,说明末端氧化过程对于醛类性信息素组分特定比例的形成不起作用。棉铃虫性信息素腺体组织具有较高的乙酸酯酶活性,可水解外源乙酸酯,但烟青虫性信息素腺体乙酸酯酶活性很低。这些发现对于进一步了解两种昆虫的生殖隔离机制有重要参考价值。     

中国豆野螟性信息素腺体组份的化学结构鉴定

研究中国豆野螟Marucavitrata(Fabricius)性信息素腺体成分。分析证实(反,反)-10,12-十六碳二烯醛(E,E-10,12-16∶ALD)是中国豆野螟性信息素腺体的主要组份;同时利用GC和GC-MS发现(反,反)-10,12-十六碳二烯醇(E,E-10,12-16∶OH)和反-10-十六碳单烯醛(E-10-16∶ALD)也是中国豆野螟性信息素腺体的组份;三者在腺体中分别以51∶4∶45的比例存在。     

沙棘木蠹蛾(鳞翅目：木蠹蛾科)性信息素组分鉴定及其生物活性

报道了沙棘木蠹蛾性信息素的结构及组分,并报道了不同组分：顺-3-十四碳烯醇;反-3-十四碳烯醇;顺-3-十四碳乙酸酯;反-3-十四碳乙酸酯;顺-7-十四碳烯醇;顺-7-十四碳乙酸酯;顺-9-十四碳乙酸酯的室内触角电位反应和林间诱捕试验。林间诱蛾结果表明2组分和5组分的诱蛾活性高于其它组合。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.