The complete genome of hydrocarbon-degrading Pseudoalteromonas sp. NJ289 and its phylogenetic relationship

Genus Pseudoalteromonas belongs to Family Pseudoalteromonadaceae in Gammaproteobacteria. A cold-adapted gram-negative bacterium, hydrocarbon-degrading Pseudoalteromonas sp. NJ289, was isolated from sea-ice of the Antarctica region, and sequenced the whole genome through the next generation sequencing platform. The assembly yielded three contigs representing two chromosomes and one plasmid with the sizes of 3.2 Mb, 636 kb and 1.8 kb, respectively. The G＋C contents of genome were 40.83% and included 3 589 ORFs. Functional annotation indicated some potential roles in enzymatic activity and environmental adaptability. This study may help for understanding the population diverse, evolutionary ecology and the microbial interaction.

An aquaporin and an aquaglyceroporin have roles in low temperature adaptation of mosquitoes (Anopheles sinensis)

Mosquitoes(Anopheles sinensis),widely geographically distributed in Asia including China,are the primary vector of the malaria parasite Plasmodium vivax and other parasitic diseases such as Malayan filariasis.An.sinensis can survive through low winter temperatures.Aquaporin channels are found in all life forms,where they facilitate environmental adaptation by allowing rapid trans-cellular movement of water(classical aquaporins)or water and solutes such as glycerol(aquaglyceroporins).Here,we identified and characterized 2 aquaporin(AQP)homologs in An.sinensis:AsAQP2(An.sinensis aquaglyceroporin)and AsAQP4(An.sinensis aquaporin).When expressed in frog(Xenopus laevis)oocytes,AsAQP2 transported water,glycerol,and urea;AsAQP4 transported only water.Water permeation through AsAQP2 and AsAQP4 was inhibited by mercuric chloride.AsAQP2 expression was slightly higher in adult female mosquitoes than in males,and AsAQP4 expression was significantly higher in adult males.The 2 AsAQPs were highly expressed in Malpighian tubules and midgut.AsAQP2 and AsAQP4 expression was up-regulated by blood feeding compared with sugar feeding.At freezing point(0℃),the AsAQP4 expression level increased and An.sinensis survival time reduced compared with those at normal temperature(26℃).At low temperature(8℃),the AsAQP2 and AsAQP4 expression levels decreased and survival time was significantly longer compared with those at 26℃.These results suggest that AsAQP2 and AsAQP4 have roles in water homeostasis during blood digestion and in low temperature adaptation of A.sinensis.Together,our results show that the 2 AQPs are important for mosquito diuresis after blood feeding and when exposed to low temperatures.