The Movement of Hormosira banksii (Fucales, Phaeophyta) Spermatozoids in Response to Sexual Pheromone

The swimming behaviour of Hormosira banksii spermatozoids wasstudied using videomicroscopy under different conditions, includingmovement on glass surfaces, on solvent droplets containing thespecies-specific gamete attractant at different concentrationsand in relation to eggs. The results indicate a chemotaxis mechanisminvolving phobic responses as well as a kinesis in which theturning rate is reduced upon stimulation by pheromone. Preliminarydata on respiration and carbon assimilation of spermatozoidsare also reported. Key words: Hormosira, Fucales, Chemotaxis, Pheromone, Movement     

Temperature Effect on the Photo-Accumulation and Phobic Response of Volvox aureus*

SYNOPSIS. The effect of temperature on photoaccumulation and photophobic response of Volvox aureus were studied. The algae exhibited positive photoaccumulation at room temperature and negative at low temperature. When stimulated with light of intermediate intensiy (～ 5 × 10³ lux), the phobic response of the algae consisted of a decrease in the frequency or the cessation of flagellar movement in the anterior cells. At room temperature, an increase in light intensity elicited the phobic response, whereas at low temperature a decrease in light intensity was the effective stimulus. The phobic response lasted only a few seconds. The positive and negative photoaccumulations of the algae could be explained by the brief cessation of flagellar movement in the anterior cells, elicited by an increase of stimulus light at room temperature or a decrease of stimulus at low temperature.     

Light Inhibits Flagellation in a Chlamydomonas Mutant

We have isolated a new flagellar mutant in Chlamydomonas reinhardtii.When the mutant was cultured under the white fluorescent lamp({small tilde}4,800 lux), most cells had no flagella. However,when the cultures were put in the dark, flagellation occurred.Greater than 70% of the cells had flagella within 12–16h after the transfer. The flagellar morphology varied from "rod-shape"(same as the wild-type flagella) to "disk-shape". The disk-shapedflagella had the axonemes which were curved into a loop withinthe swollen membrane. Hence, this mutant is called loop-1. Light-inhibitionof flagellation was restored in the presence of 10^–5 MDCMU. The spectral dependency of the photo-inhibition of flagellation,determined using the Okazaki Large Spectrograph, showed maximaleffectiveness at 400–420 nm and 600–680 nm. Theseresults suggest that photosynthesis inhibits flagellation ofloop-1 cells. (Received July 27, 1989; Accepted January 29, 1990)     

How is Pheromone Specificity Encoded in Proteins?

Pheromone specificity in the Lepidoptera is encoded in proteincomponents of the antennal sensillum lymph and dendritic membrane.In this paper, we highlight recent work on the molecular determinantsof pheromone binding affinity of pheromone binding proteins(PBPS) of three genera. First, we describe new cDNA sequencesfor Lymantria dispar (Lymantriidae) and Agrotis segetum (Noctuidae).These data enrich the conclusions derived from our functionalstudies. Secondly, we indicate how preparation of multimilligramquantities of the recombinant PBP ‘Apol-3’ (originallyfrom Antheraea polyphemus) has provided a platform (i) to determinethe ligand binding sites using photoaffinity labeling, (ii)to conduct structural analysis by CD and NMR, and (iii) to measurebinding affinities using a new binding assay. Thirdly, we describethe use of expression-cassette PCR technology to prepare tworelated PBPS from Antheraea perneyi to test binding affinitiesof naturally-occurring homologous PBPs. Our results supporta model in which ligand specificity for chain length, doublebond position, and terminal functionality is partially encodedin the PBPS. We propose that the final decoding is accomplishedwhen the PBP-pheromone complex activates a G-protein coupledseven-transmembrane domain receptor that contains recognitionsites for both the presented pheromone and the presenting PBP.Chem. Senses 20: 461–469, 1995.     

Effects of Trifluoromethyl Ketones and Related Compounds on the EAG and Behavioural Responses to Pheromones in Male Moths

Trifluoromethyl ketones (TFMKs) and analogues affect pheromonedetection and behaviour in male moths. 3-Octylthio-1, 1, 1-trifluoropropan-2-one(OTFP), one of the most effective antiesterase agents, decreasedthe EAG amplitude and increased the repolarization time in spodopteralittoralis. It also modified EAG responses of Marnestra brassicaeand Heliothis zea to their pheromones and analogues, containingan acetate, an alcohol or an aldehyde function. In addition,OTFP also reduced the amplitude of the EAG response to linalool,a monoterpenic alcohol, but not its kinetics. The responsesof male S. littoralis to the pheromone in the wind tunnel weresignificantly reduced after pre-exposure to vapours of OTFP.Comparison of the activity of other TFMKs and analogues withthat of OTFP revealed a good agreement on EAG and behaviour.The effects of TFMKs on the EAG kinetics are discussed consideringthe hypothesis of an inhibition of the pheromone deactivationin the antenna. Chem. Senses 22: 407–416, 1997.     

Female pheromonal chorusing in an arctiid moth, Utetheisa ornatrix

We report an unusual case of communal sexual display in thearctiid moth Utetheisa ornatrix that we designate "female pheromonalchorusing." As in most moths, female U. ornatrix release a long-distancesexual advertisement pheromone during a nightly activity period.We arranged U. ornatrix females in 2 types of signaling conditions:grouped and solitary. When the females were grouped with neighboringsignaling females (grouped), they initiated pheromone releasesooner, continued release with less interruption and over alonger total period, and performed the release with faster abdominalpumping than observed in isolated females (solitary). This differsfrom the usual form of sexual communication in moths: female(chemical) signalers, male receivers, and a general lack ofinteraction among females. At mating, male U. ornatrix transfera large spermatophore that may enhance female reproductive successand which represents either mating effort or paternal investment.This action results in an extended postmating male refractoryperiod leading to a female-biased operational sex ratio. Weargue that this biased sex ratio generates intrasexual competitionamong females, to which they respond by elevating signalingeffort such that the likelihood of at least matching their neighbors'signals is increased. In the field, U. ornatrix are clusteredaround patches of host plants, and we also explore the possibilitythat pheromonal chorusing is driven by cooperation among groupsof related—or nonrelated—females.     

Effect of Extracellular Ca2+ and Ca2+-Antagonists on the Movement and Chemoorientation of Male Gametes of Ectocarpus siliculosus (Phaeophyceae)

Chemoorientation in male gametes of Ectocarpus siliculosus in response to sexual pheromones is effected by two distinct mechanisms, chemokinesis and chemoklinotaxis. These are characterized by a strongly asymmetric bending pattern of the anteriorly-directed flagellum and transient unilateral bending of the hind flagellum, respectively. Removal of extracellular Ca²⁺ showed that normal flagellar movement and chemokinesis require millimolar concentrations of Ca²⁺ in the medium. The response to pheromones is strongly inhibited by La³⁺, whereas the Ca²⁺-channel drugs, verapamil and nifedipine, have only little effect. Nifedipine nethertheless effectively inhibited accumulation at pheromone sources. These results are interpreted as an indication for the involvement of two pharmacologically distinct Ca²⁺-channels in chemokinesis and chemoklinotaxis. The calmodulin-antagonist, trifluoperazine, induces, at low concentrations, the same flagellar response in chemokinesis as the pheromone, the mechanism of action remaining unknown.     

Discrimination of female sex pheromone by male Trichoplusia ni (Hubner)

The olfactory discrimination process of male cabbage loopermoths, Trichoplusa ni (Hübner), was assessed by measuringtheir response to one of two emission sources within a windtunnel. The males discriminated between (1) Z7–12:Ac concentrations;(2) Z7–12:Ac alone and the volatile emission from excisedfemale sex pheromone glands; and (3) Z7–12:Ac and theemission from a mixture of six synthetic pheromone componentsthat mimics the volatile emissions of a female gland. Althoughmales could discriminate between a freshly excised female sexpheromone gland and 7.4x 10^–11 M Z7–12:Ac, theycould not discriminate between a gland and 78.5x10^–11M Z7–12:Ac. Males also could not discriminate betweenthe mixture of six volatile compounds and 28.7x10^–11 Mof Z7–12:Ac. The data show that male cabbage looper mothshave difficulty discriminating between Z7–12:Ac aloneand in mixtures with other female-emitted volatile compounds.     

玉米螟赤眼蜂对亚洲玉米螟益它素的嗅觉反应

在实验室条件下利用四臂嗅觉仪测定了玉米螟赤眼蜂Trichogramma ostriniae Pang et Chen对来源于寄主亚洲玉米螟Ostrinia furnacalis (Guenée)成虫、卵、附腺以及性信息素的益它素的嗅觉反应。结果表明: 已交配尚未产卵亚洲玉米螟雌蛾及其附腺对玉米螟赤眼蜂有明显的吸引作用,而处女蛾、产卵前期雌蛾、产卵后期雌蛾及其附腺却没有作用;当玉米螟卵块数量为2块及卵表正己烷提取物当量为0.25块卵时,对玉米螟赤眼蜂也有明显的吸引作用,尤其以产在玻璃管内卵块吸引最为显著,达到极显著水平(P<0.01);性信息素组分之一,反-12-十四碳烯乙酸酯(E12.14: Ac)在剂量为1 μg时亦显著刺激了赤眼蜂的活动,表现为进入处理区的次数明显增加,且滞留时间明显延长。     

A snail's space sets a snail's pace: movement rates of lavigeria gastropods in lake tanganyika, East africa

Endemic Lavigeria gastropods are diverse and common in the benthosof Lake Tanganyika. We used in situ studies of marked individualsto quantify rates of daily movement by three species, and testthe effects of size, sex, reproductive status and parasitismon movement. Average net travel distance was 50 cm day^–1,which corresponds to about 20 times shell length. Male L. coronatamoved significantly farther than L. coronata females or L. grandis,and L. nassa of either sex. There were also significant differencesamong individuals within each group; however, these differenceswere not predicted by size, reproductive status or parasitism.We interpret greater movement of L. coronata males as a reflectionof mate searching; the ratio of males to non-brooding, non-parasitizedfemales was three times as high in L. coronata (21:1) as inthe other species (6:1). Our results indicate that these snailsare capable of moving considerable distances, and that the highlylocalized distribution of L. coronata populations is not simplya reflection of limited movement by individual snails. (Received 20 September 2006; accepted 1 March 2007)     

Effects of Colchicine, Vinblastine, Cytochalasin B and Phalloidin on the Seismonastic Movement of Mimosa pudica Leaf and on Motor Cell Ultrastructure

Fleurat-Lessard, P., Roblin, G., Bonmort, J. and Besse, C. 1988.Effects of colchicine, vinblastine, cytochalasin B and phalloidinon the seismonastic movement of Mimosa pudica leaf and on motorcell ultrastructure.—J. exp. Bot. 39: 209–221. Colchicine at 1 x 10^–3 mol dm^–3 does not affectthe seismonastic movement of Mimosa pudica leaves but disruptsmicrotubules in motor cells. Vinblastine at 5 x 10^–3 moldm^–3 does not affect this movement and partly disruptsmicrotubules. Vinblastine at 1 x 10^–4 mol dm^–3 alwaysdisrupts microtubules, even after a 12 h reversibility whenthe movement is restored. These drugs, applied at the same respectiveconcentrations, do not alter cytoplasmic and vacuolar fibrils.Cytochalasin B and phalloidin alter the seismonastic movementof Mimosa leaves when applied at concentrations of 1.25 x 10^–3and 2.4 x 10^–4 mol dm^–3 respectively. These drugs,used at the same respective concentrations, also affect themotor cell structure and, in particular, modify the arrangementand the structure of the fibrils but they do not destroy themicrotubules. These data suggest that microtubules are not directly involvedin the seismonastic reaction whereas fibrils, formed by thin(3.0 nm wide) filaments, may be implicated in this reaction. Key words: Colchicine, cytochalasin B, phalloidin, Mimosa pudica, motor cells, vinblastine     

Electroantennographic resolution of pulsed pheromone plumes in two species of moths with bipectinate antennae

Trains of 20-ms-duration pulses of pheromone were deliveredat rates of 1–33 Hz to antennal preparations of malesof Bombyx mori and Lymantria dispar, two moth species with bipectinateantennae. Resolution of rapidly pulsed plumes of pheromone wasnot compromised by a complex antennal morphology or by moderatechanges in wind speed (25–50 cm/s). Fourier analysis ofthe electroantennograms resolved the temporal structure of thesignal at frequencies up to 25 Hz for B. mori and up to 5 Hzfor L. dispar. The ability of these sensory structures to identifythe original (unchanged) frequency of the pulse train is particularlynoteworthy because air is slowed by about an order of magnitudeas it passes through bipectinate antennae. Although an unchangingfrequency in slowed airflow may be counterintuitive, this flowpattern, and its effects on odorant patch shape and spacing,is explained from fluid mechanical principles (i.e., the principleof continuity). An unchanging frequency suggests that as deceleratingair passes through a bipectinate antenna, the slowed patchesof odorant are stretched, thinned, and brought closer togetherby the same factor with which they are slowed.     

LOCALIZATION AND REACTIONS OF A PHEROMONE DEGRADATIVE ENZYME ISOLATED FROM AN INSECT ANTENNA

A fluid isolated from chemosensory sensilla on the antennaeof males and females of the cabbage looper, Trichoplusia ni(Hübner), was fractionated by gel filtration. Enzymaticdegradation of the pheromone was associated with 2 distinctgroups of fractions. The first group contained membrane fragments,vesicles, and membrane-bound enzyme or insoluble enzyme aggregates.The second group of fractions contained solublilized enzyme.Because of the method of isolating the ‘sensillum liquor’by breaking the tips of the hairs, membranes from chemoreceptorcell dendrites should greatly predominate. In general, 3 isomersand the saturated analog of the pheromone were hydrolyzed morerapidly than the pheromone. ^*Mention of a proprietary product in this paper does not constitutean endorsement of this product by the U. S. Department of Agriculture.     

Oscillations of the Membrane Potential of Pulvinar Motor Cells In Situ in Relation to Leaflet Movements of Desmodium motorium

The ultradian rhythmic movement of the lateral leaflets of Desmodiummotorium is accompanied by rhythmic changes of the extra- andintracellular electrical potentials in the pulvinus, which aremeasured in situ in the pulvinus against the bathing solutionof the petiole. Extra- and intracellular potentials oscillatewith 180'b0 phase difference to each other, as shown by simultaneousmeasurements of both types of potentials in the abaxial partof the pulvinus. Light-induced changes of these potentials movein opposite directions. The in situ membrane potential of themotor cells of the pulvinus was calculated from the differencebetween the extra- and intracellular potentials. It was foundto oscillate between –136 and –36 mV, in phase withthe intracellular and inverse to the extracellular potential.The phase relationship between the leaflet movement rhythm andthe in situ membrane potential rhythm was as follows: downwardmovement is preceded and accompanied by a strong depolarization,upward movement by hyperpolarization. Our results suggest that membrane depolarization in pulvinarmotor cells of Desmodium motorium drives and controls potassiumefflux and hyperpolarization potassium influx via potassiumchannels. Key words: Desmodium pulvinus, leaf movement, pulvinar motor cells, electrical potential     

Attraction between social crab spiders: silk pheromones in Diaea socialis

The snare web is used as a medium for communication betweenindividuals within colonies of social spiders and has thereforebeen suggested as necessary for the evolution of sociality inthe Araneae. The social spider Diaea socialis (Thomisidae) isan exception because it does not build a snare web. Experimentsdemonstrate that silk attracts all spiders and that a chemicaldeposited onto the silk attracts adult female spiders, suggestingthat the group living of this species is mediated by a pheromone.The pheromone attracts spiders differentially: females are notattracted to juvenile silk, and it repels gravid females. Thepheromone appears to be stable but volatile, is ether-soluble,and retains its viability after dissolution. Molecular-ionicmasses for 7-8 different compounds were found in the range 220–281atomic units; the pheromone may be one or a combination of severalof these.     

Purification, Identification, Concentration and Bioactivity of (Z)-7-Dodecen-1-yl Acetate: Sex Pheromone of the Female Asian Elephant, Elephas maximus

In their natural ecosystems, adult male and female Asian elephants,Elephas maximus, live separately. For several weeks prior toovulation, female elephants release a substance in their urinewhich elicits a high frequency of non-habituating chemosensoryresponses, especially flehmen responses, from male elephants.These responses occur prior to, and are an integral part of,mating. Using bioassay-guided fractionation, quantitativelydependent on these chemosensory responses, a specific sex pheromonewas isolated and purified by an alternating series of organicand/or aqueous extractions, column chromatography, gas chromatographyand high-performance liquid chromatography. Using primarily¹H-proton nuclear magnetic resonance (NMR) spectrometry andgas chromatography-mass spectrometry (GC-MS) of the urine-derivedpheromone and its dimethyl disulfide derivative, we determinedthe structure of the active compound to be (Z)-7-dodecen-1-ylacetate (Z7-12:Ac). Concentrations of Z7-12:Ac in the femaleurine increased from non-detectable during the luteal phaseto 0.48µg/ml (0.002 mM) early in the follicular phaseand to 33.0µg/ml (0.146 mM) just prior to ovulation. Bioassayswith commercially available authentic synthetic Z7-12:Ac, using10 Asian male elephants at several locations in the US, demonstratedquantitatively elevated chemosensory responses that were robustduring successive tests, and several mating-associated behaviors.Bioassays with Z7-12:Ac with adult male elephants dwelling inmore natural social situations in forest camps in Myanmar revealedsome differing contextual pre-mating behavioral components.The remarkable convergent evolution of this compound suggeststhat compounds identified in mammalian exudates that are alsopresent in pheromone blends of insects should be re-evaluatedas potential mammalian chemosignals. Chem. Senses 22: 417–437,1997.     

Purification and Characterization of a Novel Sex Pheromone that Induces the Release of Another Sex Pheromone during Sexual Reproduction of the Heterothallic Closterium peracerosum-strigosum-littorale Complex

A sex pheromone, PR-IP Inducer, which is released from mating-typeminus cells of Closterium, was purified by monitoring its biologicaleffect on the induction of the release of protoplast-release-inducingprotein (PR-IP) from mating-type plus cells. The purified PR-IPInducer had an apparent molecular mass of 22 kDa and of 18.7kDa as determined by SDS-PAGE and mass-spectrometric analysis,respectively. Staining with periodic acid-Schiff reagent indicatedthat PR-IP Inducer included a glycan chain. From the analysisof a dose-response curve, it seemed that PR-IP Inducer was ableto exert its activity over quite wide range of concentrations(1 x 10^–10–3 x 10^–7 M). It appears that PR-IPInducer is a novel glycoproteinaceous pheromone, as is PR-IP,and that it exerts its effect at the earliest stages of thesexual reproduction of the Closterium peracerosum-strigosum-littoralecomplex. ¹Recipient of a Fellowship for Japanese Junior Scientists fromthe Japan Society for the Promotion of Science.     

Spatial and temporal variation in pheromone composition of ant foraging trails

Many social insects use pheromones to communicate and coordinatetheir activities. Investigation of intraspecific differencesin pheromone use is a new area of social insect research. Forexample, interindividual variation in alarm pheromone contenthas been found in physical castes of polymorphic ants. Manyant species use multiple trail pheromones. Here we present novelresearch into trail pheromone variations between behavioralsubcastes of pharaoh ants, Monomorium pharaonis. Monomoriumpharaonis is attracted to trail pheromones found in its poisonglands (monomorines) and Dufour's glands (faranal). We showthat the most abundant monomorines, I (M1) and III (M3), canbe readily detected in pheromone trails. A behaviorally distinctsubcaste known as "pathfinder" foragers can relocate long-livedpheromone trails. Chemical analysis showed that pathfinder foragershad low M3:M1 ratios (mean 3.09 ± 1.53, range 1.03–7.10).Nonpathfinder foragers had significantly greater M3:M1 ratios(38.3 ± 60.0, range 3.54–289). We found that M3:M1ratio did not differ between foragers of different age but wascorrelated with behavioral subcaste at all ages. The relativeabundance of M3:M1 on foraging trails ranged from 3.03–41.3over time during pheromone trail build-up. M3:M1 ratio alsovaried spatially throughout trail networks, being lowest ontrail sections closest to a food source (M3:M1 = 1.9–3.61)and highest near the nest (M3:M1 = 67–267). Our resultsindicate a functional role for differences in pheromone trailcomposition, whereby pathfinder foragers might preferentiallymark sections of pheromone trail networks for future exploration.     

旋花蛾性信息素成分的鉴定

提取和鉴定了杂草田旋花Convolvulus arvensis的天敌旋花蛾Tyta luctuosa的性信息素主要成分,并应用风洞实验对雄蛾进行了测试。结果表明,腺体提取物和雌蛾求偶时所释放的主要性信息素成分均为2种化合物：顺-9-十四碳烯醛（Z9-14∶Ald）和顺-11-十六碳烯醛（Z11-16∶Ald）。腺体提取物中2种化合物的总量在个体间差异很大（22～167 ng）,但二者的比率相对稳定（Z9-14∶Ald/Z11-16∶Ald=0.3±0.15）。雌蛾所释放的性信息素量及比率在个体间也存在差异。每只雌蛾求偶时平均每小时释放94 ng Z9-14∶Ald和45 ng Z11-16∶Ald,平均比率为2.2。风洞实验结果显示,48%的雄蛾可被合成的性信息素混合物（0.4 μg Z9-14∶Ald, 2 μg Z11-16∶Ald）引诱完成逆风飞行并最终触及刺激源,而2种对照组（以求偶期雌蛾或性信息素腺体提取物为刺激源）的引诱率则分别为62%和44%。     

The abts and sulp families of anion transporters from Caenorhabditis elegans

The slc4 and slc26 gene families encode two distinct groups of gene products that transport HCO₃^– and other anions in mammalian cells. The SLC4 and SLC26 proteins are important contributors to transepithelial movement of fluids and electrolytes and to cellular pH and volume regulation. Herein we describe the cDNA cloning from the nematode Caenorhabditis elegans of four anion bicarbonate transporter (abts) homologs of slc4 cDNA and eight sulfate permease (sulp) homologs of slc26 cDNA. Analysis of transgenic nematode strains carrying promoter::GFP fusions suggests relatively restricted expression patterns for many of these genes. At least three genes are expressed primarily in the intestine, three are expressed primarily in the excretory cell, and one is expressed in both of these polarized cell types. One of the genes is also expressed exclusively in the myoepithelium-like cells of the pharynx. Many of the sulp gene products localize to the basolateral membrane rather than to the apical membrane. Several ABTS and SULP proteins exhibited anion transport function in Xenopus oocytes. The strongest Cl^– transporter among these also mediated Cl^–/HCO₃^– exchange. These findings encourage exploitation of the genetic strengths of the nematode model system in the study of the physiological roles of anion transport by the proteins of these two highly conserved gene families.