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closeisolation of components
Posted by PatriciaCB on 25 Feb 2011 at 11:23 GMT
Morning, your work appears as a nice first approach in the chemical trabsmition of signals in sexual behaviour in fish. However, I'd like to know if you have analyzed the composition profile (cromatography, spectrofometry, steroids ELISA or other tehcnique), at least at a general level, of the substances present in the urine and the surrounding water to be sure that the response recorded is related to a "pheromone" and to other factors like osmolarity gradient or other non-pheromone related substances that should present and collected in the urine and male containing water.
RE: isolation of components
nigrensis replied to PatriciaCB on 25 Feb 2011 at 15:51 GMT
Patricia,
Thanks for your comment. My PhD student, Rongfeng Cui, is currently working on the chemical characterization of pheromone cues and has this to say: "We are in the process of characterizing the chemical nature of the attractants in male X. malinche water. We are using HPLC and mass spectrometry for that project. We did find unique peaks in the profile that has activity. However the data are preliminary and need more work.
Given the dilution of the cue and low flow rate (5ml/min) in the trial, it is unlikely for the females to detect non-pheromone odors at such low concentration (the O.D. absorbances of the putative HPLC peaks of the cue extracted from 0.8L male water are smaller than 0.02). However we don't have definitive evidence (such as EOG of using concentration gradients) for our fish yet.
I think the idea that the females are attracted to general physical gradient, such as pH, salinity or osmolarity can be ruled out because we match these on both sides during the trial (using control water) and again, given the slow flow rate, any small difference of general physical properties between the cue and water side can be neglected. "