Hemocyanin subunits composition as a molecular marker for identification of Intra-specific variations of Gammarus

Crustacean hemocyanins represent a unique case of molecular heterogeneity among oxygen-carrying proteins. Two populations of Gammarus lacustris and six populations of Gammarus komareki were identified and isolated from aquatic habitats of Ardabil (northwest of Iran). The populations were nominated based on name of isolated region. Principal component analysis of morphological absolute attributes showed that the populations were relatively dissociated. The Meshkin population of G. komareki was completely different from other populations. The analysis of relative attributes was not shown any dissociation. Hemolymph profile analysis using Native PAGE revealed 5 to 7 hemocyanin subunits for four populations of G. komareki and 8 subunits for two populations of G. lacustris. Detection of copper ions using bathocuproin sulfonate on Native PAGE surface confirmed the hemocyanin bands. Using SDS PAGE, 1-3 and 1 protein bands were separated for hemolymph samples from G. lacustris and G. komareki, respectively. Molecular weights of the bands were 75 - 80 KDa. Comparison of our results with the previous published data confirms species specificity of hemocyanin subunit composition. These results imply that ecological variation may affect the morphological traits, but the hemocyanin profiles are useful as a molecular marker for taxonomic studies and identifying very closely-related species of Gammarus.