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

Crustacean hemocyanin represents 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 the name of the isolated region. The Principal component analysis of morphological absolute attributes showed that the populations were relatively dissociated. The Meshkin population of G. komareki was completely different from the other populations. The analysis of relative attributes did not show any dissociation. The 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. The Detection of copper ions using bathocuproin sulfonate on the 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 the species specificity of hemocyanin subunit composition. These results imply that the ecological variation may affect the morphological traits, but the hemocyanin profiles are useful as a molecular marker for the taxonomic studies and identifying very closely-related species of Gammarus.