Algal pheromone:Pheromone Resources

Algal pheromone:

Algal pheromones are used for various purposes like sex-inducing, sexual reproduction, male-attractant, gamete releasing, attracting pheromones etc.

Biosynthesis of the algal pheromone fucoserratene by the freshwater diatom  Asterionella formosa  (Bacillariophyceae) (Hombeck  and Boland,1998). The fresh water diatom Gomphonema parvulum (Bacillariophyceae) produces the algal pheromones hormosirene 2 (C₁₁H₁₆) and dictyopterene A 16 (C₁₁H₁₈) from highly unsaturated eicosanoic acids like 20:5 (ω−3) 21 and 20:4 (ω−6) 14. The oxidative degradation is believed to proceed by cleavage of an intermediate 9-hydroperoxide like 6 by a hydroperoxide-lyase to yield 9-oxo-nona-(5Z.7E)-dienoic acid 8 and the corresponding C₁₁ hydrocarbon  ( Pohnert et al.,1996). The freshwater diatom Asterionella formosa (Bacillariophyceae) produces octa-1,3E,5Z-triene (6) (fucoserratene), previously identified as the sexual pheromone of the brown seaweed Fucus serratus. Fucoserratene is biosynthesised from eicosa-5,8,11,14,17-pentaenoic acid (7) by oxidative cleavage of the corresponding 12-hydroperoxy intermediate 8. The biosynthetic sequence was established using eicosa-5,8,11,14-tetraen-17-ynoic acid (18), a structural analogue of 7, which was converted to octa-1,3E-dien-5-yne (21), a structural analogue of 6, by homogenates of Asterionella Formosa (Hombeck  and Boland,1998).

Unsaturated C₈ and C₁₁ hydrocarbons act as chemical signals (chemotaxis) during sexual reproduction of many marine brown algae. One of these compounds, namely (+)-(6S)-6-(1Z-butenyl)cyclohepta-1,4-diene (=ectocarpene) is also formed as a major hydrocarbon by the flowering plant Senecio isatideus (Asteraceae). On administration of enantiospecifically labelled (8R)- or (8S)-[7,8-²H₂]trideca-3,6,9-trienoic acid instead of the natural precursor dodeca-3,6,9-trienoic acid to this plant, the artificial C₁₂ analogue of ectocarpene is formed. (Hombeck, Marc and  Boland, Wilhelm.1990).

Female gametes of the marine brown algaAnalipus japonicus secrete a complex bouquet of olefinic C₁₁-hydrocarbons. The major compound is ectocarpene, while hormosirene and dictyotene are present at levels of 2%. Although a minor constituent of the pheromone bouquet, hormosirene is 100 times more active as a male-attractant than ectocarpene (Müller et al.,1990; Kochert, 1978;Maier and  Müller,1986).

Female gametes of marine brown algae release and/or attract their conspecific males by chemical signals. The majority of these compounds are unsaturated, nonfunctionalized acyclic, and/or alicyclic C11 hydrocarbons. Threshold concentrations for release and attraction are generally observed in the range of 1-1000 pmol. The blends may contain various configurational isomers of the genuine pheromones as well as mixtures of enantiomers (Boland,1995).

Several cyclic and alicyclic C₁₁ hydrocarbons have been shown to act as gamete releasing and/or attracting pheromones during sexual reproduction of brown algae (Phaeophyceae) (Boland and Mertes,1985).

The sex-inducing pheromone of the multicellular green alga Volvox carteri is a glycoprotein that triggers development of males and females at a concentration <10⁻¹⁶ M. By differential screening of a cDNA library, two novel genes were identified that are transcribed under the control of this pheromone. Unexpectedly, one gene product was characterized as a lysozyme/chitinase, and the other gene product was shown to encode a polypeptide with a striking modular composition. This polypeptide has a cysteine protease domain separated by an extensin-like module from three repeats of a chitin binding domain. (Amon Peter et al.,1998).

References:

Amon Peter, Haas Elke, and  Sumper Manfred.1998.The sex-inducing pheromone and wounding trigger the same set of genes in the multicellular green alga Volvox. The Plant Cell, 10(5):781-789.

Boland, Wilhelm and Mertes, Karin.1985.Biosynthesis of algal pheromones. European journal of biochemistry, 147(1):83-91.

Boland, Wilhelm.1995. The chemistry of gamete attraction: chemical structures, biosynthesis, and (a) biotic degradation of algal pheromones. Proceedings of the National Academy of Sciences, 92(1):37-43.

Hombeck, Marc and  Boland, Wilhelm. Biosynthesis of the algal pheromone fucoserratene by the freshwater diatom Asterionella formosa (Bacillariophyceae). Tetrahedron, 1998, vol. 54, no 37, p. 11033-11042.

Hombeck, Marc and  Boland, Wilhelm.1990.Stereochemical studies on algal pheromone biosynthesis. European Journal of Biochemistry,191(2)453-459.

 Hombeck, M. and Boland, W.1998. Biosynthesis of the algal pheromone fucoserratene by the freshwater diatom  Asterionella formosa  (Bacillariophyceae) .Tetrahedron 54:11033–11042.

Kochert, Gary.1978. Sexual pheromones in algae and fungi. Annual Review of Plant Physiology, 29(1):461-486.

Maier, I. and  Müller, D. G. 1986.Sexual pheromones in algae. Biological Bulletin, 145-175.

Müller, D. G., Kawai, H., Stache, B., et al.1990. Sexual pheromones and gamete chemotaxis in Analipus japonicus (Phaeophyceae). Experientia, 46(5):534-536.

Pohnert, Georg et Boland, Wilhelm.1996.Biosynthesis of the algal pheromone hormosirene by the fresh-water diatom Gomphonema parvulum (Bacillariophyceae). Tetrahedron,52(30):10073-10082.

Alerting pheromone:Pheromone Resources

Alerting pheromone:

Alerting pheromones are used by many organisms for danger, food source ect.

The chemical citral n the stingless bee Lestrimelitta limao  has been found in the mandibular gland. This chemical serves as a recruiting (alerting) pheromone when L.limao workers attack the nests of other stingless bees and may perhaps also function as an offensive substance (Blum, 1966). Citral also occurs in the mandibulargland secretion of the myrmecine ant Atta sexdens rubropilosa and functions as an alerting substance (Butenandt et al.,1959). This kind of alerting scent is also exhibited in bedbugs,Cimex lectularius L. (Levinson  and  Anna ,1971).

The chemical 2-Heptanone has been identified in the anal glands of the ants Conomyrma  pyramica (Roger) (Blum and  Warter, 1966) and Iridomyrmex pruinosus (Blum, Warter and  Traynham, 1966), wherein, the chemical functions as an alerting and recruiting pheromone, and  also probably for defence.

Foragers of Bombus terrestris are able to alert their nestmates to the presence of food sources. It has been supposed that this happens at least partially through the distribution of a pheromone inside the nest. The hexane extract from tergites V–VII of bumble bee workers elicits higher activity, like a successful forager does  (Dornhaus et al.,2003). While, Granero et al. (2005) have identified the chemicals involved as the presence of two monoterpenes and one sesquiterpene (eucalyptol, ocimene and farnesol) in the nest airspace and in the tergal glands increases strongly during foraging.

Pacus, Piaractus mesopotamicus, detecting the presence of a predator by conspecific  alerting pheromone is reported. (Jordão and  Volpato,2000). At least two chemicals might be involved, one of them possibly an alerting pheromone.

When honeybees sting an object they release pheromones that direct the attack of other bees towards it. 2-heptanone is the principal aggression-provoking component in the secretion of the mandibular gland (Free and  Simpson,1968).

Secretion from the posterior scent gland of fifth instar larvae of Dysdercus intermedius Dist. (Hemiptera: Pyrrhocoridae) was analysed by a combination of gas chromatography and mass spectrometry. Eight compounds, usually comprising more than 99·9 per cent of the secretion, were identified: n-dodecane, n-tridecane, n-pentadecane, hexanal, hex-2-en-1-al, 4-oxohex-2-en-1-al, oct-2-en-1-al, and 4-oxo-oct-2-en-1-al  (Calam et al.,1968).

Within the nest, the recruiter alerts its nestmates in Formicidae by a specific behaviour which consists of an accelerated antennal beating. Possibly, an alerting pheromone is emitted during this invitational behaviour, issued either from the mandibular or the poison gland (Verhaeghe,1982).

In bumble bees (Bombus terrestris), for example, successful foragers use excited motor displays and a pheromone as communication signals. In addition, bees could make use of an indirect pathway of information flow  (Dornhaus and  Chittka,2005).

In addition to the information potential foragers can get by monitoring the honeypots, successful foragers actively alert bees in the nest to the presence of food using pheromone signals. When colony nectar stores are depleted, foragers spend more time running excitedly and less time probing pots in the nest and run with higher average speed, possibly to disperse the alerting pheromone more efficiently. (Dornhaus et al., 2003).

Hex-2-en-1-al  and  Oct-2-en-1-al functions as  assembling and alerting scents produced by the bedbug Cimex lectularius L (Levinson and  Ilan,1971).

Blum, M. S., 1996, Semiochemical parsimony in the Arthropoda, Annu. Rev. Entomol.,41:353-374.

Blum,M . S., Warters, . L. and Traynhaj. M.G.1966. Chemical releasers of social behaviour. VI.The relation of structure to activity of ketones as releasers of alarm for Iridomyrmex pruinosus (Roger). J. Insect Physiol.,12:419-27.

Butenandt, A., B. Linzen, and M. Lindauer.1959.Uber einen Duftstoff aus der Mandibeldruse der Blattschnelderameise Atta sexdens rubropilosa Forel. Arch. Anat. micr. Morph.exp., 48(suppl.):12-19.

Calam, D. H. and  Youdeowei, A. 1968.Identification and functions of secretion from the posterior scent gland of fifth instar larva of the bug Dysdercus intermedius. Journal of Insect Physiology, 14(8):1147-1158.

Dornhaus, A. and  Chittka, L. 2005.Bumble bees (Bombus terrestris) store both food and information in honeypots. Behavioral Ecology, 16(3):661-666.

Dornhaus, A., Brockmann, A. and Chittka, L. 2003. Bumble bees alert to food with pheromone from tergal gland. Journal of Comparative Physiology A, 189(1)47-51.

Dornhaus, A., Brockmann, A., Chittka, A. 2003. Bumblebees alert to food with pheromone from tergal glands. J Comp Phys A 189:47–51.

Free, J. B. and  Simpson, J. 1968. The alerting pheromones of the honeybee. Zeitschrift für vergleichende Physiologie, 61(3):361-365.

Granero, A. M., Sanz, J. M. G., Gonzalez, F. J. E., Vidal, J. L. M., Dornhaus, A., Ghani, J. and  Chittka, L. 2005. Chemical compounds of the foraging recruitment pheromone in bumblebees. Naturwissenschaften, 92(8):371-374.

Jordão, L. C. and  Volpato, G. L. 2000. Chemical transfer of warning information in non-injured fish. Behaviour, 137(6):681-690.

Levinson,  H. Z. and  Anna, R. Bar Ilan .1971.Assembling and alerting scents produced by the bedbug  Cimex lectularius L. Experientia., 27(1):02-103.

Levinson, H. Z. and  Ilan, A. R. B. 1971.Assembling and alerting scents produced by the bedbug Cimex lectularius L. Experientia, 27(1):102-103.

Verhaeghe, J. C. 1982. Food recruitment in Tetramorium impurum (Hymenoptera: Formicidae). Insectes Sociaux, 29(1):67-85.

Aggressive alarm pheromone:Pheromone Resources

Aggressive alarm pheromone:

Trail and alarm communication in ant  Aneuretus simoni are mediated by the secretions of the sternal and pygidial glands, respectively. The sternal  gland produces a relatively long-lived mass recruitment pheromone. The pygidial gland opens between the 6th and 7th tergites and produces a secretion that releases aggressive alarm  (Traniello and  Jayasuriya,1981).

Reference:

Traniello, J. F. and  Jayasuriya, A. K. 1981. Chemical communication in the primitive antAneuretus simoni: The role of the sternal and pygidial glands.Journal of chemical ecology, 7(6), 1023-1033.