Pheromone measurements

Fine, J.M. and Sorensen, P.W (2005) Biologically relevant concentrations of petromyzonol sulfate, a compound of the sea lamprey migratory pheromone, measured in stream water. /. Chem. Ecol, 31, 2205-2210. 

In 1952, it was reported that a constituent of excretions from female American cockroaches of the species Periplaneta ameri-cana is an extraordinarily potent sex pheromone.1 Early attempts to isolate and characterize the active compounds were hampered because individual cockroaches store only minute amounts of the pheromone ( 1 pg), and a full 25 years elapsed before Persoons et al. reported the isolation of two extremely active compounds, periplanones A and B.2 The latter substance is present in larger relative measure and its germacranoid structure (1, without stereochemistry) was tentatively assigned on the basis of spectroscopic data. Thus, in 1976, the constitution of periplanone B was known but there remained a stereochemical problem of a rather serious nature. Roughly three years intervened between the report of the gross structure of periplanone B and the first total synthesis of this substance by W. C. Still at Columbia.3... 

Release rates of acetate esters of (2S,3S,7S)-3,7-dimethylpentadecan-2-oll and (2S,3R,7R)-3,7-dimethyltridecan-2-ol 3 from polyethylene and cotton dispensers have been measured at different temperatures and loadings. Adjustment of the initial pheromone load on polyethylene for expected temperatures should permit the formulation of a constant release rate during the entire flight period. Successful field trapping trials for N. sertifer were carried out in Sweden, the Czech Republic, Italy, and Greece [29]. 

While the earlier studies in chemical ecology of mammals were preoccupied with relatively gross measurements (e.g., presence or absence of a chemi-cal/pheromone in an olfactory stimulus), the new quantitative capabilities make it now imperative to evaluate more accurately the volatile compound ratios or patterns under different biological circumstances. 

Hudson, R. and Distel, H. (1990) Sensitivity of female rabbits to changes in photoperiod as measured by pheromone emission. J. Comp. Physiol. A 167, 225-230. 

Together, the two lobster-generated currents that can be measured around the animal s anterior end are complex and carefully controlled. They are ideally suited to carry urine, urine pheromones, and gill metabolites away from the lobster to specified directions. Simultaneously, the water displaced by these outgoing currents results in incoming currents with chemical signals from the environment that can be sampled by the antennular chemoreceptors. 

The Gaussian plume model estimates the average pheromone flux by multiplying the measured odor concentration by mean wind speed, using the following formula (Elkinton etal, 1984). Everything is the same as in the Sutton model, except that ay and az, respectively, replace the terms Cy and Cz of the Sutton model. Dispersion coefficients are determined for each experiment separately. 

It is important to identify and measure the concentrations of a number of compounds in a mixture simultaneously for several reasons. First, among related compounds there may exist precursors of active ones, and pathways of pheromone synthesis may be elucidated. This is true for steroids in the human axilla. Nixon etal. (1988) determined the concentration of five steroids extracted from axillary hair of adult men aged 18 to 40 years. The relationships in concentrations between the two ketones 5Q -androst-16-en-3-one and 4,16-androstadien-3-one suggest that axillary bacteria reduce the former to the latter with the aid of the enzyme 4-ene-5a-reductase. Humans have a low olfactory threshold for several 16-androstenes, and the fact that some men have large quantities of 16-androstenes (Nixon etal., 1988) is biologically suggestive. 

The number of measurable volatiles from fecal pellets of house mice, M. mus-culus, increased from 15 to 20 over a period of 24 hours (Goodrich etah, 1990). Urine of female house mice contains a potent but ephemeral pheromone that elicits ultrasonic (70 kHz) mating calls from males, and a longer-lasting, weak pheromone. The first disappears within 15-18 hours, while the latter remains for at least 30 days (Sipos etal., 1995). (For additional information on the life time of chemical signals, see p. 32.)... 

Sorensen, P. W., Irvine, I. A. S., Scott, A. P., and Stacey, N. E. (1992). Electrophysiologi-cal measures of olfactory sensitivity suggest that goldfish and other fish use species-specific mixtures of hormones and their metabolites as pheromones. In Chemical Signals in Vertebrates, vol. 6, ed. R. L. Doty and D. Miiller-Schwarze, pp. 357-354. New York Plenum. 

In some species, male variation in response to component ratio offset from the natural blend is somewhat modulated by ambient temperature (Linn et al, 1988). The response specificity of G. molesta and P. gossypiella to off-ratios of pheromone acetate components in a wind tunnel assay was narrower at 20 °C than at 26 °C. In the field, sexual activity in both species occurs at both of these temperatures, depending on time of year. Some field evidence of this phenomenon with P gossypiella appears in the distribution of catch in traps baited with a range of ratios measured at various times of the flight season. Flint et al. (1977) found an evidently narrower response breadth early in the season (when temperatures were cool) compared with late-season responses. In the omnivorous leafroller Platynota stultana, the optimum ratio of its two components for attraction seems to shift with temperature in the... 

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