Effects of sodium dodecylbenzene sulfonate and sodium dodecyl sulfate on the Mytilus galloprovincialis biomarker system

The effects of in vivo exposure of Mytilus galloprovincialis to two anionic surfactants (SDBS and SDS) on the molecular biomarker system were studied. After continuous exposure for 72 days, activities/levels of GST, GPx and GSH were significantly higher than in corresponding control groups following exposure to 3.000 mg/L SDS and SDBS. Activities of SOD and CAT were significantly inhibited by experimental SDBS (except CAT in 0.100 mg/L group), but not by SDS. Statistical analysis of enzyme activities/levels suggested that there were significant positive relationships between GST and GPx, and negative relationships were found between GSH and CAT, GSH and SOD. Amplified fragment length polymorphism (AFLP) results showed that a greater genotoxic effect was observed for SDBS than for SDS. Based on the above results, the biomarker system of mussels can be affected by the two anionic surfactants (>= 3.000 mg/L); it was more easily affected by SDBS than by SDS. Crown Copyright (C) 2009 Published by Elsevier Inc. All rights reserved.

Genetic variation and phylogeographic history of Picea likiangensis revealed by RAPD markers

Repeated cycles of retreat and recolonization during the Quaternary ice ages are thought to have greatly influenced current species distributions and their genetic diversity. It remains unclear how this climatic oscillation has affected the distribution of genetic diversity between populations of wind-pollinated conifers in the Qinghai-Tibetan region. In this study, we investigated the within-species genetic diversity and phylogenetic relationships of Picea likiangensis, a dominant forest species in this region using polymorphic DNA (RAPD) markers. Our results suggest that this species has high overall genetic diversity, with 85.42% of loci being polymorphic and an average expected heterozygosity (H (E)) of 0.239. However, there were relatively low levels of polymorphism at population levels and the differences between populations were not significant, with percentages of polymorphic bands (PPB) ranging from 46.88 to 69.76%, Nei's gene diversity (H (E)) from 0.179 to 0.289 and Shannon's indices (Hpop) from 0.267 to 0.421. In accordance with our proposed hypothesis, a high level of genetic differentiation among populations was detected based on Nei's genetic diversity (G (ST) = 0.256) and AMOVA analysis (Phi (st) = 0.236). Gene flow between populations was found to be limited (Nm = 1.4532) and far lower than reported for other conifer species with wide distribution ranges from other regions. No clusters corresponding to three morphological varieties found in the south, north and west, respectively, were detected in either UPGMA or PCO analyses. Our results suggest that this species may have had different refugia during the glacial stages in the southern region and that the northern variety may have multiple origins from these different refugia.