Gamete chemotaxis

The Muller assay (Muller 1976) was developed to study chemotaxis in algal gametes. For this assay, a well (12 mm diameter, 1 mm height) was created by attaching a plastic ring to the bottom of a polystyrene petri dish. The well was then filled with 0.1 ml of an algal culture medium. Test compounds were 

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Muller, D. G., Kawai, H., Stache, B., Folster, E., and Boland, W., Sexual pheromones and gamete chemotaxis in Analipus japonicus (Phaeophyceae), Experientia, 46, 534, 1990. 

Two bioassay techniques, the capillary method [58], and the drop method [63], have already been developed to study the chemotaxis of phytopathogenic zoospores and gametes of marine brown algae. We have devised a new procedure (the "particle method") which is a qualitative, rather than a quantitative, method of detecting an attractant after it has been absorbed on to an inorganic particle. This method has been used to study attractants of A. cochlioides zoospores in the roots of both spinach and pigweed (Chenopodium album). 

Is sperm chemotaxis specific, i.e., are the chemoattractants specific for each species or are there chemoattractants common to several species There is no single answer to this question. With some exceptions, species specificity appears to be the rule in marine species [102, 103]. There, the gametes are released in to seawater, and gametes of different species may be in close proximity. Therefore, in these cases, chemotaxis may be needed as one of the means to avoid interspecies fertilization. Indeed, in some marine groups (e.g., sea urchins, hydromedusae and certain ophiuroids), the specificity of sperm chemotaxis is very high. In other groups (e.g., starfish), the specificity is at the family level and, within the family, there is no specificity. In contrast, in mollusks, there appears to be no specificity at all ([35,102,103] and references therein). 

Cosson, M.P. (1990). Sperm chemotaxis, in Controls of Sperm Motility Biological and Clinical Aspects (C. Gagnon, ed.), pp. 103-135. CRC Press, Boca Raton, FL. Cummins, J.M. andYanagimachi, R. (1982). Sperm-egg ratios and the site of the acro-some reaction during in vivo fertilization in the hamster. Gamete Res. 5, 239-256. Darszon, A., Beltran, C., Felix, R., Nishigaki, T. and Trevino, C.L. (2001). Ion transport in sperm signaling. Develop. Biol. 240, 1—14. 

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