PBAN及其对昆虫性外激素的调控

本文综述了性外激素生物合成激活神经肽 (PBAN)及其对昆虫尤其是鳞翅目昆虫性外激素产生的调控 ,包括PBAN的结构、产生、转运、作用方式及保幼激素和蜕皮激素对性外激素合成的作用 ,并展望了未来的研究方向。     

昆虫神经肽PBAN的细胞内信号转导

昆虫性信息素多数为长链的不饱和醇、醋酸酯、醛或酮类,链长一般为10-20碳,主要在性信息素腺体内由乙酰辅酶A经过脂肪酸合成、碳链缩短、去饱和以及碳酰基的还原修饰等步骤合成的;而性信息素合成激活肽(pheromone biosynthesis activating neuropeptide,PBAN)是由昆虫食管下神经节中的部分神经细胞合成和分泌的神经肽,通常由33个氨基酸组成,在C-末端有一个相同的五肽序列,主要调控性信息素的生物合成。有关PBAN的细胞内信号转导是近几年的研究热点,研究显示 PBAN首先与性信息素腺体细胞表面的G蛋白偶联受体结合,随后依据昆虫种类的不同,其细胞内信号转导方式主要有三种:(1)以cAMP信号传导途径进行信号转导;(2)以cAMP和磷脂酰肌醇信号传导途径共同进行信号转导;(3)主要以Ca2 为第二信使进行信号传导。     

马尾松毛虫性外激素的新成分:化学结构鉴定和田间试验

马尾松毛虫 Dendrolimus punctatus 性外激素由顺5,反7-十二碳二烯醇(Z5,E7-12:OH)、顺5,反7-十二碳二烯乙酸酯 Z5,E7-12:Ac和顺5,反7-十二碳二烯丙酸酯(Z5,E7-12:Pr)构成。为了确定马尾松毛虫性外激素系统是否含有其它成分,我们对外激素腺体提取物进行分析,以此为基础通过田间诱蛾试验发现了某些增加诱蛾活性的新成分。     

玉米螟性外激素腺体组织学研究

昆虫性外激素的研究,近年来有了迅速发展。关于性外激素腺体的研究,国外已有很多报道,我国目前尚未见有报道。Klun(1968)报道欧洲玉米螟(Ostriniamubilalis)性外激素腺体在雌蛾腹部最后两节的节间膜上。1975年以来,我们对本地玉米螟(Ostrinia furna-calis~*)性外激素进行了分离工作,进而对玉米螟发育时期的性外激素腺体组织学作了研究。     

茶黄毒蛾Euproctis pseudoconspersa(Strand)性外激素的分离鉴定和合成(英)

茶黄毒蛾是中国南方茶树上的重要害虫,其性引诱外激素经鉴定为10,14——二甲基十五碳异丁酸酯。本研究发展了一种外消旋式外激素合成法。装有40-1000μg的诱芯能够诱扑雄蛾。合成外激素的引诱性能相当于未交配雌蛾或雌蛾提取物。     

玉米螟触角电位反应的专一性

我国的玉米螟曾被记载为欧洲玉米螟(European corn borer,Ostrinia nubilalis),在研究性信息素的过程中,曾按照Klun等(1970)鉴定的欧洲玉米螟性信息素顺-和反-11-十四碳烯醇乙酸酯这两种异构体进行合成,但未发现该两种异构体的任何配比在田间有诱蛾活性。程志青等(1980)鉴定出我国玉米螟的性信息素是顺-和反-12-十四碳烯醇乙酸酯,并根据Mutuura等(1970)作的分类鉴定,认为我国的玉米螟应为亚洲玉米螟(Asiatic corn borer,Ostrinia furnacalis)。因此,近年来国内有关玉米螟的研究报告(程志青等,1980;1982;姜仲雪等,1981;任自立等,1983)都称我国的玉米螟为亚洲玉米螟。但     

玉米螟性外激素收集法

<正> 我们在对玉米螟性外激素进行分离提纯工作中,根据Yamamoto的方法进行了改进,对玉米螟性外激素进行了直接收集探索。现将方法及结果作一介绍以供参考。     

利用微藻生产单不饱和脂肪酸——棕榈油酸

正棕榈油酸(C16:1Δ9)具有重要的营养和医药价值,进行相应产品的开发已是势在必行。目前棕榈油酸主要来源于生物合成。大田栽培的普通油料作物中棕榈油酸含量很低,而棕榈油酸含量高的野生植物存在资源少的问题,因此利用棕榈油酸含量高且能够规模培养的微藻来进行棕榈油酸的生产已成为生物技术和可再生资源研究的一个热点领域。文章介绍了棕榈油酸的原料来源,并结合笔者实验室对黄丝藻棕榈油酸的研究,综述了微藻棕榈油酸的优势及其合成途径,最后初步展望了微藻棕榈油酸研究的发展方向。     

中国野桑蚕性信息素合成激活肽(PBAN)基因的克隆及序列分析

根据家蚕(Bombyx mori)性信息素合成激活肽(pheromone biosynthesis activating neuropeptide,PBAN)基因DNA序列设计引物,扩增获得中国野桑蚕(Bombyx mandarina China)PBAN基因。分析表明,PBAN由33个氨基酸组成,在第14个氨基酸异亮氨酸和第15个氨基酸酪氨酸之间插入了698bp的内含子。根据PBAN及其基因cDNA、DNA序列分别构建分子进化树,结果显示3个水平比对结果构建的分子进化树有较好的一致性,推测PBAN基因可能适合于科、属之间的进化分析;并且PBAN基因内含子没有表现出特有的进化信息,推测PBAN基因内含子的进化与PBAN全长基因的进化在进化速率上并没有显著差别。相对于PBAN及α—SGNP、γ—SGNP,β—SGNP的进化速率相对较快,推测β—SGNP序列可能适合用于种间的进化分析。     

干旱对棉花根和下胚轴质膜脂肪酸组分及其相关酶活性的影响(简报)

棉花根和下胚轴质膜（PM）脂肪酸主要由棕榈酸（16：0）、硬脂酸（18：0）、亚油酸（18：2）和亚麻酸（18：3）组成。干旱胁迫后,PM脂肪酸论和度增加,不饱和脂肪酸和不饱和指数（IUFA）降低。其中棕榈酸含量上升和亚麻酸含量下降较大,膜透性增高,质膜H －ATPase和Ca2 －ATPase活力降低,脂氧合酶（LOX）活性增强。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.