| Autor: |
Romero-Diaz C; School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA. cromerod@asu.edu., Campos SM; Department of Biology and Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, 47405, USA.; Center for Behavioral Neuroscience, Neuroscience Institute, Georgia State University, Atlanta, GA, 30303, USA., Herrmann MA; School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA., Lewis KN; Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA., Williams DR; Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA., Soini HA; Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.; Institute for Pheromone Research, Indiana University, Bloomington, IN, 47405, USA., Novotny MV; Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.; Institute for Pheromone Research, Indiana University, Bloomington, IN, 47405, USA., Hews DK; Department of Biology, Indiana State University, Terre Haute, IN, 47809, USA., Martins EP; School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA. |
| Abstrakt: |
Single substances within complex vertebrate chemical signals could be physiologically or behaviourally active. However, the vast diversity in chemical structure, physical properties and molecular size of semiochemicals makes identifying pheromonally active compounds no easy task. Here, we identified two volatile cyclic dipeptides, cyclo(L-Leu-L-Pro) and cyclo(L-Pro-L-Pro), from the complex mixture of a chemical signal in terrestrial vertebrates (lizard genus Sceloporus), synthesised one of them and investigated their biological activity in male intra-specific communication. In a series of behavioural trials, lizards performed more chemosensory behaviour (tongue flicks, lip smacks and substrate lickings) when presented with the synthesised cyclo(L-Pro-L-Pro) chemical blend, compared to the controls, the cyclo(L-Leu-L-Pro) blend, or a combined blend with both cyclic dipeptides. The results suggest a potential semiochemical role of cyclo(L-Pro-L-Pro) and a modulating effect of cyclo(L-Leu-L-Pro) that may depend on the relative concentration of both compounds in the chemical signal. In addition, our results stress how minor compounds in complex mixtures can produce a meaningful behavioural response, how small differences in structural design are crucial for biological activity, and highlight the need for more studies to determine the complete functional landscape of biologically relevant compounds. |
