长角血蜱性信息素成分的研究

分别应用气相色谱和气质联用技术对长角血蜱(Haemaphysalis longicornis)雌蜱吸引性信息素成分进行分析.通过生物测定,确定长角血蜱雌蜱分泌的2,6-二氯酚(2,6-DCP)和2,4-二氯酚(2,4-DCP)具有性信息素的生物学作用,虫体表面点滴这2种物质,均能使交配成功率显著提高.利用气相色谱外标法确定了这2种成分在长角血蜱雌蜱不同发育期的含量变化.结果显示:雌蜱饥饿时就已经开始分泌2,4-DCP和2,6-DCP,随着吸血过程的延续,2种物质的分泌量持续增加,交配期达到峰值,交配后含量下降;不同发育期,雌蜱分泌2,4-DCP和2,6-DCP量的比例基本一致.     

长角血蜱性信息素生物合成的激素调控

用气相色谱和高效液相色谱分别对长角血蜱雌蜱盾窝腺中性信息素２，６－二氯酚含量和整体蜕皮激素２０－羟基蜕皮酮含量进行了测定。结果表明，雌蜱２，６－ＤＣＰ生物合成开始于由若早蜕出后５ｄ，之后其含量增加并在盾窝腺中沉积，吸血前后达到高峰，吸血后３ｄ开始下降，但吸血后３－５ｄ内保持在一恒定水平，此期内２，６－ＤＣＰ释放以吸引雄蜱，吸血后７ｄ即交配后含量急剧下降，饱血后下降为零。     

化学衍生电子捕获气相色谱法测定硬蜱性外激素Ⅰ——2,6-二氯酚

硬蜱是多种脊椎动物的体外寄生虫,生物学家发现它的盾窝腺是分泌性外激素的主要器官.文献报道硬蜱分泌的性外激素主要成分是2,6-二氯酚等酚类物,其含量甚微,每只仅含1～100ng,有时甚至少于1ng.本文建立了1种分析方法,即用α-溴-2,3,4,5,6五氟甲苯(PFB- Br)做衍生试剂与2,6-二氯酚在碱性条件下衍生成醚,此醚在气相色谱电子捕获检测器上有极高的响应信号.最小检测量可达0.14pg,可以不经任何提取,富集操作就可准确测定几个乃至单个硬蜱中性外激素2,6-二氯酚的含量,1实验1.1仪器与试剂日本岛津GC-9A气相色谱仪,~(63)Ni电子捕获检测器,KD浓缩器接收瓶(KD、瓶).PFB-Br美国Aldrich Chem Co产品,其丙酮标准溶液浓度为232.4mg/L,2,6-二氯酚的丙酮标准溶液浓度为1.352mg/L.     

两种硬蜱滞育的研究

在试验室条件下观察了中华革蜱、长角血蜱在不同光周期及温度下各虫态发育历期的变化.试验结果表明:不同光周期对这2种硬蜱卵孵化期、幼虫和若虫吸血期、蜕化期无显著影响.2种硬蜱的卵、幼虫及若虫期均无滞育现象.摄食前长日照处理,可诱导中华革蜱雌虫发生饱食过程延迟的滞育.其光周期反应属短日照反应型.长角血蜱在不同处理下均无滞育发生.温度对这2种硬蜱雌虫的发育有一定影响.在非滞育状态下,恒温处理的雌虫吸血期、产卵前期及产卵期一般较变温处理的雌虫时间短.     

大袋蛾(Clania varigata Snell.)雌虫性信息素分泌腺体及其释放机制的研究——Ⅱ.性信息素的室内定量生测

<正>本文报导用大袋蛾雄虫对雌虫性信息素室内定量生测的方法。通过观察雄虫对雌虫性信息素反应的行为,选择“振翅”为定量生测的“关键行为”。测定了雄虫对性信息素反应的时辰节律,选择反应峰期18:00—21:00为生测时间。在固定的室温和相对湿度的条件下,通过正交试验表明:影响雄虫反应的因子有释放性信息素的方法、照度、雄虫年龄。优选出最佳水平是:雄虫年龄为零天,释放性信息素的方法为注射器法,照度为11x。在此条件下测得性信息素浓度(x)与雄虫反应百分率(y)之间的关系为: y=116.76+15.52x。     

实验室条件下长角血蜱的生物学特性

为确定实验室条件下长角血蜱的生物学特性,以幼蜱、若蜱、雌性成蜱、雄性成蜱各1只为1组,共30组,分别接种到15只兔的耳朵上,每只兔耳上接种1组,待其饱血脱落后收集并分装于试管中,观察并记录各发育期的时间、吸血前后的体重变化、雌蜱产卵规律、孵化时间等项指标.结果表明:幼蜱、若蜱、雌蜱、雄蜱吸血后比吸血前体重平均增加15....     

二氯酚异构体光降解特性的气相色谱研究

利用所建立的分离测定2,4-二氯酚、2,6-二氯酚、3,4-二氯酚3种异构体的气相色谱方法,研究了相同条件下该3种异构体单独与混合降解时降解率的差异,以及降解率与光照时间、起始浓度、光照距离的关系.初步考察了3种异构体在模拟水样中的降解情况,300 min后降解率达95%以上.     

2-氯吡啶光氯化夺氢反应机理的量子化学研究

用PM3方法研究了2-氯吡啶光氯化夺氢反应生成不同氯代产物的两个主要基元反应过渡态,并计算比较了不同反应路径活化能的高低.结果表明,不同产物以生成2,6-二氯吡啶的活化能最低.生成2,6-二氯吡啶两个连续的基元反应的活化能分别为9.43和15.56kJ/mol,反应优先生成2,6-二氯吡啶.     

2-氯吡啶光氯化取代反应机理的量子化学研究

用PM3方法研究了2-氯吡啶光氯化取代反应的过渡态.研究结果表明,生成2,6-二氯吡啶、2,5-二氯吡啶、2,4-二氯吡啶、2,3-二氯吡啶不同产物的每一个反应通道都存在两个过渡态;反应体系沿反应坐标的变化为反应物→反应物络合物→第1过渡态→中间体→第2过渡态→产物络合物→产物;第2过渡态为主过渡态,生成2,6-二氯吡啶反应路径主过渡态的能量及活化能最低,分别为-139612.06和135.39kJ/mol,反应优先生成2,6-二氯吡啶.生成二氯吡啶反应过程中吡啶环反应部位CCl键的形成主要与共轭双键断裂同步,而CH键的断裂主要与共轭双键的重新形成同步.     

微量滴定法测定猕猴桃中维生素C的含量

采用微量滴定法对不同贮存期、及其不同部位的猕猴桃进行了维生素C含量的测定.结果表明,微量碘量法比常规碘量法简单易行,快速准确.与2,6-二氯酚靛酚法相比无显著性差异.不同部位的猕猴桃其Vc含量不同,皮下部分＞种子部分＞髓;不同贮存期其Vc含量也不同,硬猕猴桃＞软猕猴桃.     

A single class of olfactory neurons mediates behavioural responses to a Drosophila sex pheromone

Insects, like many other animals, use sex pheromones to coordinate their reproductive behaviours. Volatile pheromones are detected by odorant receptors expressed in olfactory receptor neurons (ORNs). Whereas fruit odours typically activate multiple ORN classes, pheromones are thought to act through single dedicated classes of ORN. This model predicts that activation of such an ORN class should be sufficient to trigger the appropriate behavioural response. Here we show that the Drosophila melanogaster male-specific pheromone 11-cis-vaccenyl acetate (cVA) acts through the receptor Or67d to regulate both male and female mating behaviour. Mutant males that lack Or67d inappropriately court other males, whereas mutant females are less receptive to courting males. These data suggest that cVA has opposite effects in the two sexes: inhibiting mating behaviour in males but promoting mating behaviour in females. Replacing Or67d with moth pheromone receptors renders these ORNs sensitive to the corresponding moth pheromones. In such flies, moth pheromones elicit behavioural responses that mimic the normal response to cVA. Thus, activation of a single ORN class is both necessary and sufficient to mediate behavioural responses to the Drosophila sex pheromone cVA.     

大袋蛾(Clania variegata Snell.)雌虫性信息素分泌腺体及其释放机制的研究——IV、雌成虫生理活动的日节奏与释放性信息素的机制

<正>已往虽然对许多昆虫的性行为与温度、光暗日周期的关系有很多报道,但对它们与性信息素滴度,特别是呼吸、脉搏的关系及其日节奏尚甚少报道。 据研究,大袋蛾雌虫性信息素分泌腺体不属于Noirot.C.和Quennedey.A.对昆虫表皮腺体的分类中的任何一类,而是一种新的表皮腺体。腺体结构引起了特殊的释放信息素的机制。 在腺体释放分泌的机制的研究中,虽然有的研究者对其它目的昆虫做过一些推测,但尚未见到用实验的方法进行验证的报道。 本文所报道的是对大袋蛾雌虫信息素含量、呼吸强度、心脏脉动频率的日节奏以及脉动频率与信息素释放速率间关系的研究,并阐述了大袋蛾释放信息素机制。     

EAG and behavioral responses of Helicoverpa armigera males to volatiles from poplar leaves and their combinations with sex pheromone

Electroantennogram (EAG) evaluation of selected compounds from wilted leaves of black poplar, Populus nigra, showed that phenyl acetaldehyde, methyl salicylate, (E)-2-hexenal elicited strong responses from male antennae of Helicoverpa armigera. When mixed with sex pheromone (Ph), some volatiles, e.g. phenyl acetaldehyde, benzyl alcohol, phenylethanol, methylsalicylate, linalool, benzaldehyde, (Z)-3-hexenol, (Z)-3-hexenylacetate, (Z)-6-nonenol, cineole, (E)-2-hexenal, and geraniol elicited stronger responses from male antennae than Ph alone. Wind tunnel bioassay demonstrated that various volatiles could either enhance or inhibit the effect of synthetic sex pheromone. (E)-2-hexenal, (Z)-3-hexenol and linalool in combination with Ph could not induce any male to land on source at all, whereas phenyl acetaldehyde, benzaldehyde, (Z)-6-nonenol and salicylaldehyde combined with Ph enhanced male response rates by 58.63%, 50.33%, 51.85% and 127.78%, respectively, compared to Ph alone. These results suggested that some volatiles shouldmodify sex pheromone caused behavior and that some of them could possibly be used as a tool for disrupting mating or for enhancing the effect of synthetic sex pheromone in the field.     

Female mimicry in garter snakes

In many diverse taxa, males of the same species often exhibit multiple mating strategies. One well-documented alternative male reproductive pattern is 'female mimicry', whereby males assume a female-like morphology or mimic female behaviour patterns. In some species males mimic both female morphology and behaviour. We report here female mimicry in a reptile, the red-sided garter snake (Thamnophis sirtalis parietalis). This form of mimicry is unique in that it is expressed as a physiological feminization. Courting male red-sided garter snakes detect a female-specific pheromone and normally avoid courting other males. However, a small proportion of males release a pheromone that attracts other males, as though they were females. In the field, mating aggregations of 5-17 males were observed formed around these individual attractive males, which we have termed 'she-males'. In competitive mating trails, she-males mated with females significantly more often than did normal males, demonstrating not only reproductive competence but also a possible selective advantage to males with this female-like pheromone.     

Synthesis and assessment of attractiveness and mating disruption efficacy of sex pheromone microcapsules for the diamondback moth,Plutella xylostella （L.）

Microcapsules of sex pheromone of the diamondback moth （DBM）, Plutella xylostella （Lepidoptera： Plutellidae） were synthesized through complex coacervation using gelatin and gum arabic as wall-forming materials. The encapsulated pheromone released from these microcapsules into the air was monitored over six weeks in the field. Results of a field trial show that the attractiveness of microcapsules was superior to that of rubber septa loaded with the same amount of pheromone. The mating disruption efficiency of the pheromone treatment was estimated through comparing numbers of moths captured in pheromone-baited traps placed in pheromone treatment fields and pesticide treatment fields. The estimated mating disruption efficiency of the pheromone treatments ranged from 76.94% to 98.67% during the season. This study shows that pheromone microcapsules might provide a new method for P. xylostella control.     

大袋蛾性信息素研究初报

<正>大袋蛾不但具有独特的生活习性,而且雌虫性信息素的分泌部位和化学结构亦不同于一般鳞翅目蛾类。我们的初步工作证实,大袋蛾雌成虫的性引诱能力极强,其性信息素的分泌部位主要在胸部背板区。用漂洗法提取,可消除屏蔽物质的干扰和减少杂质的污染。大袋蛾性信息素的化学结构不同于一般鳞翅目蛾类的不饱和长碳链醇、乙酸酯或醛、酮之类。其主要活性组分的分子量为270,分子式C_(17)H_(34)O_2。此外,还有多元组分存在的可能性。结构鉴定的进一步工作正在进行。     

榆斑蛾生殖生理的研究

该文对榆斑蛾Illiberis ulmivora Graeser(Lepidoptera:Zygaeoidae)成虫的生殖生理活动进行了研究,观察了成虫的求偶、交配以及雌蛾性信息素的释放行为。并对雌蛾性信息的粗提物和薄层板分离馏分进行了林间诱蛾试验,表明均有明显的诱雄蛾活性。     

A functional circuit underlying male sexual behaviour in the female mouse brain

In mice, pheromone detection is mediated by the vomeronasal organ and the main olfactory epithelium. Male mice that are deficient for Trpc2, an ion channel specifically expressed in VNO neurons and essential for VNO sensory transduction, are impaired in sex discrimination and male-male aggression. We report here that Trpc2-/- female mice show a reduction in female-specific behaviour, including maternal aggression and lactating behaviour. Strikingly, mutant females display unique characteristics of male sexual and courtship behaviours such as mounting, pelvic thrust, solicitation, anogenital olfactory investigation, and emission of complex ultrasonic vocalizations towards male and female conspecific mice. The same behavioural phenotype is observed after VNO surgical removal in adult animals, and is not accompanied by disruption of the oestrous cycle and sex hormone levels. These findings suggest that VNO-mediated pheromone inputs act in wild-type females to repress male behaviour and activate female behaviours. Moreover, they imply that functional neuronal circuits underlying male-specific behaviours exist in the normal female mouse brain.     

Sex-specific peptides from exocrine glands stimulate mouse vomeronasal sensory neurons

In mammals, social and reproductive behaviours are modulated by pheromones, which are chemical signals that convey information about sex and strain. The vomeronasal organ, located at the base of the nasal septum, is responsible for mediating pheromone information in mice. Two classes of putative pheromone receptor gene families, V1R and V2R, are expressed by vomeronasal sensory neurons in mutually segregated epithelial zones of the vomeronasal organ. Although numerous studies have suggested that pheromones originate from urine, direct recordings of behaving mice have shown that neuronal firing in the vomeronasal system is modulated by physical contact with the facial area. Here we identify a male-specific 7-kDa peptide secreted from the extraorbital lacrimal gland. This peptide, which we named exocrine gland-secreting peptide 1 (ESP1), is encoded by a gene from a previously unrecognized large family clustered in proximity to the class I major histocompatibility complex (MHC) region. ESP1 is secreted from the eyes and is transferred to the female vomeronasal organ, where it stimulates V2R-expressing vomeronasal sensory neurons and elicits an electrical response. Our results indicate that mice respond to sex-specific peptides released from exocrine glands through the vomeronasal system during direct contact.