Sex pheromone of Etiella behrii, a pod borer of soybean in Indonesia: identification and field attraction

Four EAG-active components were detected in GC-EAG analyses of hexane extracts from virgin Etiella behrii (Zeller) (Lepidoptera: Pyralidae) females. These components were identified as dodecyl acetate (12:Ac), (E)-9-dodecenyl acetate (E9-12:Ac), either (Z)-9- or (E)-11-tetradecenyl acetate (Z9- or E11-14:Ac), and (Z)-11-tetradecenyl acetate (Z11-14:Ac) by comparison of retention indices on both nonpolar and polar GC columns. The available extract was insufficient for further GC-MS or other chemical analyses (<0.2 ng/female). In field tests carried out in East Java, a 10:90 mixture of E9-12:Ac and Z11-14:Ac showed attractiveness to male moths and addition of 12:Ac and/or E11-14:Ac significantly increased the trap catches while addition of Z9-14:Ac showed no significant effect. Maximum attraction was obtained with 5.35 or 10.7 g/rubber septum of a mixture of E9-12:Ac, Z11-14:Ac, 12:Ac and E11-14:Ac at the ratio of 10:90:0.7:6.3, respectively. The role of pheromone blends in species discrimination between E. behrii and the related E. zinckenella (Treitschke) is discussed.     

Effects of dose and attractant on interactions between pheromone traps for the pea moth, Cydia nigricana

The effects of different doses of two attractants on the interactions between pheromone traps for the pea moth, Cydia nigricana (F.) were investigated. In lines of three traps along the wind, each containing 10³ g (E)-10-dodecen-1-yl acetate (E10-12: Ac), interactions were evident at spacings of 15 m and 50 m; the centre trap catch was suppressed (cf. an isolated trap) but, unlike interacting traps containing 10² g (E,E)-8, 10-dodecadien-1-yl acetate (E, E8, 10–12: Ac), the upwind trap did not catch more moths than the other traps.Changing the dose of E10-12: Ac in lines of traps with a spacing of 50 m did not affect the profile of catches, but reducing the dose of E, E8, 10–12: Ac to 1 g per trap resulted in a profile similar to that obtained with all doses of E10-12: Ac.The efficiency with which traps caught moths approaching within 1 m was affected by the attractant rather than the dose. Traps containing E, E8, 10–12: Ac were almost twice as efficient as those containing E10-12: Ac, suggesting that the former is a better close-range attractant.

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Zusammenfassung Die Wirkung verschiedener Mengen zweier Attraktivstoffe auf die gegenseitige Beeinflussung von Pheromonfallen für den Erbsenwickler, Cydia nigricana F., wurde untersucht. Drei Fallen mit je 10³ g des Pheromonanalogs (E)-10-dodecen-1-yl Acetat (E10-12: Ac), wurden in einer Reihe in der Hauptwindrichtung aufgehängt. Bei Fallenabständen von 15 m und 50 m war die gegenseitige Beeinflussung offensichtlich. Im vergleich mit isolierten Fallen wurde der Fang der zentralen Falle reduziert. Die Aufwindfalle fing nicht mehr als die andern Fallen und zwar im Gegensatz zu Versuchen, in denen die Fallen je 10² g des natürlichen Pheromons (E,E) 8, 10-dodecadien-1-yl Acetat (E, E8, 10–12: Ac) enthielten.Wenn die Menge von E10-12: Ac in Fallenreihen mit 50 m Abstand geändert wurde (z.B. 10⁴ g), wurde das Fangprofil nicht geändert. Wurde die Menge von E, E8, 10–12: Ac auf 1 g pro Falle vermindert, ergab sich ein Profil, das allen Kombinationen von E10-12: Ac entsprach.Die Fängigkeit der Fallen im Nahbereich von 1 m wurde mehr durch den Lockstoff als durch die Menge beeinflusst. Fallen mit E, E8, 10–12: Ac waren fast zweimal fängiger als Fallen mit E10-12: Ac (37% und 22%). Demnach scheint die erste Substanz der bessere Nahdistanzlockstoff zu sein.

     

Female sex pheromone of the Chinese tortrix Cydia trasias

The Chinese tortrix, Cydia trasias (Meyrick) (Lepidoptera: Tortricidae), is a major pest of the Chinese scholar-tree (Japanese pagoda tree), Sophora japonica L. Cydia trasias has two or three generations in Beijing, China and overwinters as larvae in seed pods, bark crevices, and twigs of the Chinese scholar-tree (Chen, 1992; Chen & Qi, 1992). The larvae attack both petioles and seed pods. During outbreaks, the larvae can cause extensive leaf drop, bare twigs, and seed pod damage, reducing the ornamental and economic value of the tree (Enda & Yamazaki, 1987; Chen, 1992). Since the Chinese scholar-tree is one of the most popular ornamental trees in urban and suburban areas, trees are sprayed with insecticide to control C. trasias outbreaks. Earlier field trials showed that C. trasias can be controlled by mating disruption (Zhang et al., 2001). In our early paper and patent (Fu & Meng, 1997; Meng et al., 1998), we reported E8,E10-dodecadienyl acetate (E8,E10-12:Ac) as a pheromone component of C. trasias, but the identification of C. trasias sex pheromone was not complete. We report here the identification and field testing of the female-produced sex pheromone in C. trasias.     

Development of Sex Pheromone Trap for Monitoring Matsumuraeses falcana (Walshingham) (Lepidoptera: Tortricidae)

This study was carried out to find out an effective formulation for monitoring the soybean podborer, Matsumuraeses falcana (Walshingham), using its sex pheromone in Korea. A 1 : 1 : 1 mixture of (E)-8-dodecenyl acetate (E 8–12: Ac), (E,E)-8,10-dodecadienyl acetate (E 8 E 10–12: Ac) and (E,Z)-7,9-dodecadienyl acetate (E 7 Z 9–12: Ac) was an effective composition in monitoring M. falcana. A binary mixture of E 8–12: Ac and E 8 E 10–12: Ac was essential to attract M. falcana male moths. E 7 Z 9–12: Ac showed a synergistic effect on the attractiveness of 1 : 1 mixture of E 8–12: Ac and E 8 E 10–12: Ac. These chemicals alone showed little or no attractiveness to M. falcana. The sticky-typed wing trap baited with sex pheromone captured significantly more males than the water-pan trap. Trap catches within a soybean field were much more than those in perimeter trap. The trap-baited with sex pheromone gave a distinct fluctuation pattern of male catches throughout the flight seasons. Therefore, it can be expected that pheromone-baited trap provides a simple tool for monitoring the soybean podborer, M. falcana in Korea.     

Sex pheromone of the African armyworm <Emphasis Type="Italic">Spodoptera exempta</Emphasis> (Lepidoptera: Noctuidae): identification of components of the Okinawan population and formulation for population monitoring

In 2010, abrupt outbreaks of the African armyworm, Spodoptera exempta (Walker), occured on the Tarama, Iriomote and Kikai Islands in southwestern Japan. Analysis by gas chromatography-electroantennographic detection (GC-EAD) revealed two EAG-active compounds on male antenna in crude extract of virgin females. These compounds were identified as (9Z)-9-tetradecenyl acetate (Z9-14:Ac) and (9Z,12E)-9,12-tetradecadienyl acetate (Z9E12-14:Ac) in ca. 90:10 ratio by subsequent GC-MS analyses. (11Z)-11-Hexadecenyl acetate (Z11-16:Ac), which had previously been identified as a third component in the Kenyan population, was not detected. Binary blends of Z9-14:Ac and Z9E12-14:Ac at ratios between 99:1 and 90:10 showed a potent attractiveness in the field, superior to that of virgin females and comparable to that of the three-component formulation determined in Kenya. For the population survey, a 98:2 blend was used. In Tarama, only a few moths of S. exempta were captured with a light trap during the night when more than 600 males were captured with synthetic sex pheromone; more S. exempta captures with a light trap had been reported than with sex-pheromone traps in Kenya. This indicates that the Okinawan population has different properties from the Kenyan population in pheromone composition and behavioral response to light.     

Sex pheromone of a North American population of the spotted tentiform leafminer, Phyllonorycter blancardella

The major sex pheromone compound of the spotted tentiform leafminer, Phyllonorycter blancardella (F.) (Lepidoptera: Gracillariidae), from Ontario, Canada, was identified as (10E)‐dodecen‐1‐yl acetate (E10‐12:Ac) using chemical analysis and field trapping experiments. The minor compounds (10E)‐dodecen‐1‐ol (E10‐12:OH) (4.6%), dodecan‐1‐ol (12:OH) (2.3%), and (10Z)‐dodecen‐1‐yl acetate (Z10‐12:Ac) 1.6% were also identified. The dienic acetate (4E,10E)‐dodecadien‐1‐yl acetate (E4,E10‐12:Ac), a compound reported to be attractive to P. blancardella, was not found in the glands of this population. A two‐component blend of the major and one of each the three minor compounds, in ratios similar to those found in the sex pheromone gland, did not increase the attractiveness of traps baited with synthetic pheromone. The minor compounds E10‐12:OH and 12:OH were not attractive to P. blancardella when tested individually. Z10‐12:Ac was attractive to P. blancardella, although traps baited with this compound captured only 2% of the moths that were captured in traps baited with the main compound. A four‐component blend of the major and each of the three minor compounds (100 : 1 : 1 : 1) was not more attractive than the major compound alone. The related species Phyllonorycter mespilella was captured in traps baited with E10‐12:Ac.     

Effects of varying sex pheromone component ratios on the zigzagging flight movements of the oriental fruit moth,Grapholita molesta

As the ratio of (E)-8-dodecenyl acetate (E8–12Ac) to (Z)-8-dodecenyl acetate (Z8–12Ac) increased past optimal low levels in the pheromone blend, fewer males were able to fly 2.5 m upwind to the source. The tracks of males that flew in plumes of such high-(E)off-blends were slower and narrower than those of males flying to lower-(E)blends. The tracks were narrower, first of all, because as the proportion of E8–12Ac increased, the males steered more into the wind. More of their thrust was directed upwind and therefore their groundspeed to either side of the windline was reduced. In addition, males also reduced their airspeeds to high-(E)blends, which contributed to the decreased groundspeeds and narrower tracks. No significant changes in the frequency of counterturning were found in response to increasing proportions of E8–12Ac. The inability to continue upwind flight in a plume of an off ratio was indicated by in-flight arrestment in the plume. Arrestment resulted from changes in the course angles steered by the males and the airspeeds flown.     

Female sex pheromone of a nettle caterpillar,Monema flavescens,in China

Monema flavescens Walker (Lepidoptera: Limacodidae) is a multivoltine, generalist moth whose larvae cause serious damage to many types of trees. Pheromone lures prepared according to a study of a Japanese population were found to be ineffective at attracting M. flavescens nettle caterpillars in China, and some studies have shown intraspecific geographical differences in the composition of sex pheromones. We therefore reexamined the sex pheromone composition of M. flavescens in a Chinese population. In this study, the electroantennographically (EAG) active compounds in an extract from Chinese virgin females of M. flavescens were identified as (E)‐8‐decen‐1‐ol (E8‐10:OH), (Z)‐7,9‐decadien‐1‐ol (Z7,9‐10:OH), (Z)‐9,11‐dodecadien‐1‐ol (Z9,11‐12:OH), and (Z)‐9,11‐dodecadienal (Z9,11‐12:Ald) via coupled gas chromatographic‐electroantennographic detection (GC‐EAD) and coupled GC‐mass spectrometry (MS). Pheromone dimorphism might occur in this species, as this mixture of compounds in Chinese females was different from that of E8‐10:OH and E7,9‐10:OH extracted from Japanese females in previous research. In wind tunnel and field tests, the males were significantly attracted to a blend of the pheromone components E8‐10:OH, Z7,9‐10:OH, and Z9,11‐12:OH in a 100:5:4 ratio. The addition of Z9,11‐12:Ald did not change the male response. The optimized three‐component lure blend may provide a useful tool for monitoring and controlling Chinese populations of M. flavescens.     

Sex pheromone of the iris gelechiid moth Monochroa divisella

The iris gelechiid moth, Monochroa divisella (Douglas) (Lepidoptera: Gelechiidae), is a serious pest in iris horticulture. The overuse of pesticides for conventional control has a great risk of water pollution because irises are often planted in damp areas. To minimize pesticide applications, it is essential to monitor moth emergence by using pheromone traps. The female pheromone of M. divisella was analyzed by means of gas chromatography‐electroantennographic detection (GC‐EAD) and GC‐mass spectrometry. Two male EAD‐active compounds were detected and identified as (Z)‐3‐dodecenyl acetate (Z3‐12:Ac) and (Z)‐5‐tetradecenyl acetate (Z5‐14:Ac), the amounts of which were ca. 40 and 6 ng per female (100:15), respectively. Synthetic Z3‐12:Ac alone attracted only a few males in field trap experiments, but the attractiveness was significantly enhanced when 15% (wt/wt) Z5‐14:Ac was added; traps baited with their binary mixtures captured 21.3‐106.4 males/trap/day, as compared with 2.3 males/trap/day attracted by a crude extract of 10 virgin females. We conclude that Z3‐12:Ac and Z5‐14:Ac are M. divisella pheromone components, which can be offered as an attractant in monitoring traps. Although dodecenyl acetates are a major class of lepidopteran pheromone components, those with the double bond at the 3 position are rare and appear to be unique to gelechiids.     

Sex pheromone components of the carpenterworm moth,Holcocerus vicarius

Extracts of the female sex pheromone gland of the carpenterworm moth, Holcocerus vicarius (Walker) (Lepidoptera: Cossidae), a pest of Ulmus pumila L. (Ulmaceae), were found to contain Z7‐tetradecenyl acetate (Z7‐14Ac), E3‐tetradecenyl acetate (E3‐14Ac), (Z3,E5)‐tetradecenyl acetate (Z3,E5‐14Ac), and Z7‐tetradecenyl alcohol (Z7‐14OH) by coupled gas chromatographic‐electroantennographic detection (GC‐EAD) and coupled gas chromatography‐mass spectrometry (GC‐MS). Field trapping studies with impregnated rubber septa indicated that Z7‐14Ac was essential for attraction of males of H. vicarius. However, the most attractive blend contained Z7‐14Ac, E3‐14Ac, Z3,E5‐14Ac, and Z7‐14OH in a 50:22:17:10 ratio. Our results demonstrated that a blend of Z7‐14Ac, E3‐14Ac, Z3,E5‐14Ac, and Z7‐14OH represented the sex pheromone of H. vicarius. The optimized four‐component lure blend may be useful for monitoring H. vicarius infestations and mating disruption.     

苏云金芽胞杆菌高效表达载体的构建

[目的]通过比较cry1A、cry3A、cry4A和cry8E四个基因的启动子转录活性,筛选出一个强启动子,利用强启动子构建一个苏云金芽胞杆菌(Bacillus thuringiensis,简称Bt)高效表达载体.[方法]利用启动子融合lacZ技术检测了4种启动子的转录活性.通过扫描电子显微镜观察晶体、SDS-PAGE、蛋白定量和生物活性测定等方法对新建高效表达载体进行功能验证.[结果]构建了Pcry1A、Pcry3A、Pcry4A和Pcry8E4个启动子融合报告基因lacZ的表达载体,经β-半乳糖苷酶活性分析得知,启动子活性从高到低依次为Pcry8E＞Pcry1A＞Pcry4A＞Pcry3A.选取cry8E启动子,以pHT315作为基础载体构建苏云金芽胞杆菌高效表达载体pHT315-8E21b,将cry1Ac基因连接到pHT315-8E21b和广泛应用的cry3A启动子指导的pSXY-422b上,分别转入无晶体突变株HD-73-,获得菌株HD-8E1Ac和HD-422-1Ac.扫描电子显微镜观察显示,HD-8E1Ac菌株可以形成菱形晶体,说明正确表达了cry1Ac基因.SDS-PAGE分析结合蛋白定量实验表明pHT315-8E21b表达效率高于pSXY-422b.对小菜蛾(Plutella xylostella)的生物活性测定表明HD-8E1Ac菌株对小菜蛾有生物活性,且菌株活性高于HD-422-1Ac.[结论]利用强启动子Pcry8E构建了一个能在Bt中高效表达的穿梭载体pHT315-8E21b,该载体可正确表达cry1Ac基因,其表达效率高于被广泛应用的pSXY422b.     

Chemical communication in heliothine moths. VII. Correlation between diminished responses to point-source plumes and single filaments similarly tainted with a behavioral antagonist

Addition of (Z)-11-hexadecenyl acetate (Z11-16:Ac) into a normally attractive binary blend of Heliothis virescens pheromone components resulted in a suppression of upwind flight and source location by males. Male response was reduced even at the lowest dosages of Z11-16:Ac tested but upwind flight and source location were most clearly reduced when the loading of Z11-16:Ac reached 10% or more of the (Z)-11-hexadecenal (Z11-16:Ald) loading (the major component present in the binary blend). Similar patterns of suppression in response were noted when Z11-16:Ac was added to binary blends of pheromone components at both 10 and 100 μg loadings of Z11-16:Ald. Males in casting flight following upwind flight in a mechanically generated pulsed plume, responded to the interception of a subsequent, single binary-blend filament by making a toward-source upwind surge. Responses of males to a single filament that was tainted by a level of Z11-16:Ac that had allowed some reduced level of upwind flight and source location to occur in the previous plume experiments were diminished compared with their control counterparts. Analysis of the flight tracks revealed that the surges in response to single tainted filaments were stunted because males made fewer significant changes in course angles steered, airspeeds generated, and in the tempo of counterturns executed. Accepted: 28 December 1996     

Trapping effect of synthetic sex pheromone of Acleris fimbriana (Lepidoptera: Tortricidae) in Chinese northern orchard

The yellow tortrix, Acleris fimbriana Merick (Lepidoptera: Tortricidae), is an economically important insect pest on fruit trees with four generations a year in North China. In order to develop a new and effective method for forecasting and controlling the pest, the sex pheromone was studied. We have identified the female sex pheromone as (E)-11,13-tetradecadienal (E11,13-14:Ald), (E)-11,13-tetradecadienyl acetate (E11,13-14:Ac) and (E)-11-tetradecenyl acetate (E11-14:Ac). Trapping effect of synthetic chemicals E11,13-14:Ald, alone and in combination with E11,13-14:Ac or/and E11-14:Ac to A. fimbriana males was tested in Beijing Xishan Orchard (2001). E11,13-14:Ald on its own was much attractive to A. fimbriana males. Neither E11,13-14:Ac nor E11-14:Ac alone caught any moths. The catches markedly increased by adding E11,13-14:Ac to E11,13-14:Ald. The optimum ratio of E11,13-14:Ald and E11,13-14:Ac was 6:4 to 5:5. This attractiveness was apparently enhanced when 5% to 10% of E11-14:Ac was added. The best field activity was in the lure baited with a 6:4:1 ratio of E11,13-14:Ald, E11,13-14:Ac and E11-14:Ac at a dosage of 1000 microg/septum. The effect of antioxidant, 2,6-di-tert-butyl-4-methylphenol [butylated hydroxyluene (BHT)], to the synthetic pheromone blends on its duration and catching efficacy was also tested. Addition of 5-10% BHT to the synthetic pheromone could prolong the life-span of pheromone chemicals for 6-8 weeks, thereby increased its catching efficacy.     

Antipyretic properties of centrally administered α-MSH fragments in the rabbit

alpha-Melanocyte stimulating hormone (alpha-MSH 1-13) has marked antipyretic effects when administered centrally or peripherally in small doses. A C-terminal fragment, alpha-MSH (11-13), contains an antipyretic message sequence of alpha-MSH; however, the lesser potency of this fragment relative to that of the entire molecule suggests that other amino acids of the alpha-MSH sequence are essential for the full antipyretic effect. Graded doses of alpha-MSH (11-13) (Ac LysProVal NH2), alpha-MSH (10-13) (Ac GlyLysProVal NH2), and alpha-MSH (8-13) (Ac ArgTrpGlyLysProVal NH2), were injected into the cerebral ventricles of rabbits made febrile by IV administration of crude interleukin-1. All three fragments reduced fever in a dose-related manner. The (8-13) sequence was much more effective than the other two fragments, and the (10-13) portion was less effective than the (11-13) tripeptide. None of the fragments was as potent as alpha-MSH (1-13). The results confirm that an antipyretic message resides within alpha-MSH (11-13) and sequential addition of amino acids to alpha-MSH (11-13) can both enhance and reduce the potency of the fragment.     

Identification of a four-component sex pheromone blend in Bonagota cranaodes (Lepidoptera: Tortricidae)

Analysis of sex pheromone glands of the apple leafroller Bonagota cranaodes Meyrick by gas chromatography coupled with mass spectrometry or electroantennographic detection showed the presence of 14 structurally related acetates and alcohols of the chain length 10-18, including the main pheromone component (E,Z)-3,5-dodecadienyl acetate (E3,Z5-12Ac). Male antennae responded to the main compound, its Z,Z isomer, (E,Z) -3,5-tetradecadienyl acetate (E3,Z5-14Ac), and the monoenes (Z)-5-dodecenyl acetate (Z5-12Ac) and (Z)-9-hexadecenyl acetate (Z9-16Ac). Traps baited with a four-component blend of E3,Z5-12Ac, Z5-12Ac, E3,Z5-14Ac, and Z9-16Ac in a 100:5:5:100 ratio were significantly more attractive than the main compound alone. This improved trap lure is more suitable for monitoring population densities of B. cranaodes, and for detection of the onset of the seasonal flight period. A more complete pheromone blend is of importance also with respect to current attempts to develop mating disruption for control of this major pest of apple in Brazil.     

大螟雄蛾触角对性外激素及其类似物的电生理反应

电生理试验显示出:大螟Sesamia inferens(Walker)雄蛾触角对Z11-16:Ac(A)oZ11-16:OH(B)激起强烈的触角电位(EAG)反应,Z11-16:ALD?,E11-16:Ac(D),Z9-14:Ac(E)和Z7-12:Ac(F)四种化合物也能激起较强的EAG反应;A化合物的刺激阈比B高,此两种化合物5:5比例时,激起的反应最强烈。电生理的试验推测,雄蛾触角对A和B两种化合物的感受,是通过触角内两种不同类型的嗅觉感受器。A和B不同比例混合后,田间诱蛾试验证明:在9:1,8:2,5:5的比例时,其诱蛾量远远超过单独的A化合物;E加入A与B的混合物中,起抑制诱蛾的效果,上述试验表明,Z11-16:OH是大螟的性诱剂。     

Overexpression of long non-coding RNA RP11-363E7.4 inhibits proliferation and invasion in gastric cancer

LncRNA RP11-363E7.4 has been shown to be downregulated in gastric cancer (GC), while the effect of lncRNA RP11-363E7.4 on GC and its potential molecular mechanisms is unclear. The purpose of this study was to explore the functional role and underlying molecular mechanisms of lncRNA RP11-363E7.4 involved in GC progress.To address the question, quantitative real-time PCR assay was performed to confirm lncRNA RP11-363E7.4 expression levels in GC tissues and cell lines. Cell proliferation, apoptosis, migration and invasion were estimated using Cell Counting Kit-8, colony formation, scratch wound healing and Transwell assays. Potential molecular mechanisms were evaluated using western blot assay. The results showed that lncRNA RP11-363E7.4 was significantly downregulated in GC cell lines and 82 paired tissues. The correlation between expression and clinicopathological features indicated that low expression of lncRNA RP11-363E7.4 was associated with T stage (P = .010). Functional experiments showed that overexpression of lncRNA RP11-363E7.4 prevented proliferation, migration, and invasion and induced apoptosis of GC cells. Western blot assay revealed that lncRNA RP11-363E7.4 functioned via the p53, Bax/Bcl-2, β-catenin pathway. In summary, this study revealed that lncRNA RP11-363E7.4 functioned as a tumour suppressor by inhibiting proliferation, migration, and invasion and inducing apoptosis of GC cells. Significance of the study :LncRNA RP11-363E7.4 has been shown to be downregulated in GC, while the effect of lncRNA RP11-363E7.4 on GC and its potential molecular mechanism is unclear. We revealed that lncRNA RP11-363E7.4 functioned as a tumour suppressor by inhibiting proliferation, migration, and invasion and inducing apoptosis of GC cells. LncRNA RP11-363E7.4 might become an attractive diagnostic and prognostic biomarker of GC and a promising target for GC treatment.     

Molecular dynamics simulations of certain mutant peptide models from staphylococcal nuclease reveal that initial hydrophobic collapse associated with turn propensity drives β‐hairpin folding

An important nucleation event during the folding of staphylococcal nuclease involves the formation of a β‐hairpin by the sequence ²¹DTVKLMYKGQPMTFR³⁵. Earlier studies show that the turn sequence ‘YKGQP’ has an important role in the folding of this β‐hairpin. To understand the active or passive nature of the turn sequence ‘YKGQP’ in the folding of the aforementioned β‐hairpin sequence, we studied glycine mutant peptides Ac‐²DTVKLMYGGQPMTFR¹⁶‐NMe (K9G:15), Ac‐²DTVKLMYKGGPMTFR¹⁶‐NMe (Q11G:15), Ac‐²DTVKLMYGGGPMTFR¹⁶‐NMe (K9G/Q11G:15), and Ac‐²DTVKLMGGGGGMTFR¹⁶‐NMe (penta‐G:15) by using molecular dynamics simulations, starting with two different unfolded states, polyproline II and extended conformational forms. Further, 5mer mutant turn peptides Ac‐²YGGQP⁶‐NMe (K3G:5), Ac‐²YKGGP⁶‐NMe (Q5G:5), Ac‐²YGGGP⁶‐NMe (K3G/Q5G:5), and Ac‐²GGGGG⁶‐NMe (penta‐G:5) were also studied individually. Our results show that an initial hydrophobic collapse and loop closure occurs in all 15mer mutants, but only K9G:15 mutant forms a stable native‐like β‐hairpin. In the other 15mer mutants, the hydrophobic collapsed state would not proceed to β‐hairpin formation. Of the different simulations performed for the penta‐G:15 mutant, in only one simulation a nonnative β‐hairpin conformation is sampled with highly flexible loop region (⁸GGGGG¹²), which has no specific conformational preference as a 5mer. While the sequence ‘YGGQP’ in the K3G:5 simulation shows relatively higher β‐turn propensity, the presence of this sequence in K9G:15 peptide seems to be driving the β‐hairpin formation. Thus, these results seem to suggest that for the formation of a stable β‐hairpin, the initial hydrophobic collapse is to be assisted by a turn propensity. Initial hydrophobic collapse alone is not sufficient to guide β‐hairpin formation. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.     

Modification of sex pheromone blend discrimination in male Oriental fruit moths by pre-exposure to (E)-8-dodecenyl acetate

ABSTRACT. A pre-exposure regime was developed to test the hypothesis that arrestment of in-flight behaviour in Oriental fruit moths, Grapholitha molesta (Busck), to high dosage and/or high %( E )-8-dodecenyl acetate blends was due to a high proportion of E8-12: Ac in the pheromone blend. When tested in a sustained-flight tunnel to various ratios of ( Z )- and ( E )-8-dodecenyl acetate plus a constant % of Z8-12: OH at two dosages (3 and 100μg), males displayed an optimum number of completed flights to the source to the natural 6% E blend at 3 μg, with significant decreases in response levels occurring to high % E blends at both dosages. Pre-exposure of males to E8-12: Ac alone enhanced their response at each dosage to selected higher % E blends that normally elicited low numbers of completed flights. Pre-exposure enhanced all aspects of the flight response, but this was dependent on both dosage and duration of pre-exposure, with later behaviours in the sequence (landing and hairpencil display) requiring greater amounts of pre-exposure than early behaviour (taking flight). Pre-exposure did not affect high response levels to optimal blends or low response levels to the highest or lowest blends tested at each dosage. The selective nature of the pre-exposure effect implied alteration of central processes in discrimination of blend rather than disturbance of olfactory receptor function.     

Epibionts on the krill (Euphausia pacifica) from the E coast of Japan

Fernandez‐Leborans, G. 2011. Epibionts on the krill (Euphausia pacifica) from the E coast of Japan. —Acta Zoologica (Stockholm) 00 : 1–10. Specimens of Euphausia pacifica collected from shallow waters of the E coast of Japan showed ciliate epibionts belonging to two suctorian species: Ephelota plana and Gymnodinioides sp. The epibionts were present in a total of 27 anatomical units of E. pacifica, in numbers fluctuating between 8 and 80 individuals per basibiont. Gymnodinioides showed the highest mean number of epibionts. The presence–absence of epibionts indicated some specificity of the species by different locations on the basibiont body, which is corroborated by the analysis of the colonization throughout the longitudinal axis of the basibiont. Ephelota plana was recorded by the first time on E. pacifica, while Gymnodinioides sp. extended its geographical area with respect to previous studies. Morphological, taxonomical features of the species and the statistical analysis of their spatial distribution on E. pacifica are included.