Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors approximately 100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector-human and vector-parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi.
Title: Worms from the Arctic are better adapted to freezing and high salinity than worms from temperate regions: Oxidative stress responses in Enchytraeus albidus Silva AL, Holmstrup M, Amorim MJ Ref: Comparative Biochemistry & Physiology A Comparative Physiology Mol Integr Physiol, 166:582, 2013 : PubMed
Enchytraeus albidus is a freeze-tolerant enchytraeid found in diverse habitats, from supra-littoral to terrestrial, and spanning temperate to arctic regions. Thus, this worm is often exposed to sub-zero temperatures and fluctuating salinity regimes that can lead to physiological stress. We therefore studied the oxidative stress by measuring lipid peroxidation, anti-oxidant defenses and neurotransmission activity in E. albidus from arctic (Greenland) and temperate (Germany) regions during a short-term exposure to saline conditions (0, 15, 35 and 50 per thousand NaCl) and low temperatures (+2, -2 and -5 degrees C). Various enzymatic and non-enzymatic oxidative stress markers were analyzed. Results have shown that both salt and freezing caused oxidative stress in E. albidus, particularly from Germany, as confirmed by catalase, glutathione-S-transferase and superoxide dismutase activities and lipid peroxidation levels. Neurotransmission (as judged from acetylcholinesterase activity) was reduced by saline conditions at +2 degrees C, but stimulated at -2 and -5 degrees C. Worms from Greenland had relatively higher and more stable levels of antioxidants than worms from Germany, reflecting their higher tolerance of freezing and saline conditions.
