Preovulatory pheromone

Rasmussen, L.E.L. (2001) Source and cyclic release pattern of Z-7-dodecenyl acetate, the preovulatory pheromone of the female Asian elephant. Chem. Senses 26, 611-623. 

FIGURE 7.1 Female goldfish pheromones, (a) The preovulatory pheromone 17a, 20/3-dihydroxypregn-4-en-3 one (b) the postovulatory pheromone 15-keto-prostaglandin 2 -... 

Rasmussen, L., Krishnamurthy, V., and Sukumar, R., in prep. Behavioral and chemical confirmation of the preovulatory pheromone, (Z)-7-dodecenyl acetate, in wild Asian elephants and its relationship to musth. 

This paper focuses on the ecological and biochemical constraints imposed on such chemical communication. Our analysis of these constraints and their relationship to chemical communication will include (1) the evolution of chemical signals in elephants (2) the operational levels of chemical signals within elephant society (behavioral and/or physiological conditions of the emitters and responders are important constraints) and (3) the types of chemicals available as potential chemical signals. We will focus on two specific chemical signals to illustrate these constraints (1) volatile emissions from male Asian elephants in musth, and (2) (Z)-7-dodecenyl acetate, a female preovulatory pheromone. 

Table III. Properties of preovulatory pheromone from female Asian elephants...

Nine stimuli were used. These were 3 non-familiar stimuli (amyl acetate, B-ionone, 2-phenylethanol 10 M), various relevant natural stimuli, such as 4 amino acids (L-Ala, L-Glu, L-Arg, L-Lys 10 - 10 M), a bile acid (taurolithocholic acid, I0 - 10" M), and a preovulatory pheromone (17a,20B-dihydroxy-4-pregnen-3-one, 10" - 10 M). The compounds were dissolved in tap water and for 15s repetitively applied to the olfactory epithelium. The 15s stimulus applications were interrupted by 180s tap water application of similar (1 ml/min) velocity during the interstimulus phases. 

Recently McClintock (375) showed that preovulatory pheromone from female rats shortened or phase advanced the ovarian cycles, whereas ovulatory odors lengthened or phase-delayed the cycle of females. 

Sorensen P.W., Hara T.J., Stacey N.E. and Dulka J.G. (1990). Extreme olfactory specificity of male goldfish to the preovulatory steroidal pheromone-17a20p-dihydroxy-4-pregnen-3-one. J Comp Physiol (A) 166, 373-383. 

In fish reproduction, the best-investigated pheromone system is that of the goldfish [Carassius auratus). Here, sex steroids and prostaglandins play important roles. The female produces two pheromones sequentially a preovulatory primer pheromone and a postovulatory prostaglandin pheromone that act on the male. 

CHEMICAL ANALYSIS OF PREOVULATORY FEMALE AFRICAN ELEPHANT URINE A SEARCH FOR PUTATIVE PHEROMONES... 

Redundant component A component which induces a response by interacting with olfactory receptors associated with neural pathways for more potent (primary, secondary, or inhibitory) components. These are not recognized in their own right by the animal s nervous system not required for a mixture to have significant activity but, when present, amplify the activity of other components and thus the mixture. 17a,20p,21P appears to be a redundant component of the goldfish preovulatory steroidal pheromone (see Section 3). 

For three reasons, we believe that the goldfish preovulatory steroid pheromone (which appears to function primarily to increase male fertility during sperm competition Zheng et al., 1997) is used in spying rather than communication (as defined in this essay). 

Stacey, N.E., Sorensen, P.W., Van Der Kraak, G.J. Dulka, J.G. 1989. Direct evidence that 17a,20p-dihydroxy-4-pregnen-3-one functions as a goldfish primer pheromone preovulatory release is closely associated with male endocrine responses. Gen. Comp. Endocrinol. 75, 62—70. 

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