Chemotaxis species specificity

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). 

What is the situation in mammals The need for species specificity in mammalian sperm chemotaxis is not obvious. On the one hand, specificity might be desired as a mean to avoid cross-species fertilization. 

Miller, R.L. 1979. Sperm chemotaxis in the Hydromedusae. I. Species-specificity and sperm behavior. Mar. Biol. 53 99-114. 

M. mnthus development. The key to bacterial coordinated behavior resides in the ability of a cell to receive, interpret, and respond to these signals. Relaying the information may require direct contact between the donor and the recipient cells or it may be carried out from a distance, i.e., by means of diffusible molecules, which are detected through their interaction with specific receptors. As discussed in Chapter 3, bacterial chemotaxis is the most completely understood of the bacterial sensory transduction systems. While the role of chemotaxis in intercellular communication is still not clear, in some cases, mutants deleted for chemotaxis genes fail to carry out one or another of the processes mentioned above. Components of the chemotaxis system seem to play a role in swarming motility, pattern formation, and myxobacterial development. In fact, it appears that certain chemotaxis functions have been recruited by certain species to mediate intercellular communication. In this chapter, we review some examples, and provide evidence as well as hypotheses concerning a role for proteins and systems involved in chemotaxis in multicellular behavior. 

In plants, a unique simple compound [for example, fucoserratene—a linear, unsaturated alkene (1,3-trans 5-cis-octatriene)] might be a chemoattractant for various species [92]. These differences in specificity between species may reflect the different physiological tasks that sperm chemotaxis fulfills in different species. 

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