Na+/K+-ATPase (NKA) belongs to the P-type ATPase family, whose members are located in the cell membrane and are distributed in diverse tissues and cells. The main function of the NKA is to regulate osmotic pressure. To better understand the role of NKA in osmoregulation, we first cloned and characterized the full-length cDNAs of NKA α subunit and β subunit from Pacific abalone Haliotis discus hannai in the current study. The predicted protein sequence of the NKA α subunit, as the catalytic subunit, was well conserved. In contrast, the protein sequence of the β subunit had low similarity with those of other species. Phylogenetic analysis revealed that both the α and β subunits of the NKA protein of Pacific abalone were clustered with those of the Gastropoda. Then, the relationship between salinity changes and the NKA was investigated. Sudden salinity changes (with low-salinity seawater (LSW) or high-salinity seawater (HSW)) led to clear changes in ion concentration (Na+ and K+) in hemolymph; however, the relative stability of ion concentrations in tissue revealed that Pacific abalone has a strong osmotic pressure regulation ability when faced with these salinity changes. Meanwhile, the expression and activity of the NKA was significantly decreased (in LSW group) or increased (in HSW group) during the ion concentration re-establishing stages, which was consistent with the coordinated regulation of ion concentration in hemolymph. Moreover, a positive correlation between cyclic adenosine monophosphate (cAMP) concentrations and NKA mRNA expression (NKA activity) was observed in mantle and gill. Therefore, the sudden salinity changes may affect NKA transcription activation, translation and enzyme activity via a cAMP-mediated pathway.

the two subspecies of atlantic bay scallop (Argopecten irradians), A. i. irradians and A. i. concentricus, are economically important aquacultural species in northern and southern China. Here, we performed the whole-genome sequencing, assembly, and gene annotation and produced draft genomes for both subspecies. In total, 253.17 and 272.97 gigabases (Gb) of raw reads were generated from Illumina Hiseq and PacBio platforms for A. i. irradians and A. i. concentricus, respectively. Draft genomes of 835.7 Mb and 874.82 Mb were assembled for the two subspecies, accounting for 83.9% and 89.79% of the estimated sizes of their corresponding genomes, respectively. The contig N50 and scaffold N50 were 78.54 kb and 1.53 Mb for the A. i. irradians genome, and those for the A. i. concentricus genome were 63.73 kb and 1.25 Mb. Moreover, 26,777 and 25,979 protein-coding genes were predicted for A. i. irradians and A. i. concentricus, respectively. these valuable genome assemblies lay a solid foundation for future theoretical studies and provide guidance for practical scallop breeding.

This study reports an outbreak of acute febrile respiratory illness caused by human adenovirus B [P14H11F14] in a military training center in China between May and June 2014. In total, 164 military personnel were affected, and two patients were admitted into the intensive care unit of the military regional central hospital. A HAdV-B [P14H11F14] virus was confirmed as the etiological pathogen of this acute outbreak of febrile respiratory illness based on clinical manifestations, epidemiological characteristics, specific molecular detection results, phylogenetic analysis, and serological assays. The virus was isolated by the rhabdomyosarcoma cell culture method, and the complete sequences of the E1A, penton base, hexon, and fiber genes were determined and deposited in the GenBank database. Phylogenetic and sequence homology analyses indicated that the isolated strain is most closely related to some HAdV-55 strains from mainland China. However, this strain appeared to be less virulent than former HAdV-55 strains. According to the chest X-ray results of 31 affected patients, there was no radiological evidence of pneumonia. The most frequent symptoms in these patients were sore throat (95.12 %, 156/164) and tonsillitis (93.29 %, 153/164). During the course of the outbreak, incorrect response measures and some potential risk factors, such as fire training and marching training, may have exacerbated the spread of the infection. This outbreak illustrates the urgent need to improve the epidemiological and etiological surveillance of HAdV infections and to improve the ability of doctors and health officials in basic units of the Chinese army to respond effectively to febrile respiratory illness.

Background: Aquaporins (AQPs), as members of the major intrinsic protein (MIP) superfamily, facilitated the permeation of water and other solutes and are involved in multiple biological processes. AQP family exists in almost all living organisms and is highly diversified in vertebrates in both classification and function due to genome wide duplication. While some AQP orthologs have been lost in higher vertebrates through evolution. Result: Genome-wide comparative analyses of the AQP family between allotetraploid frog Xenopus laevis (Xla) and diploid frog Xenopus tropicalis (Xtr), based on the genome assemblies, revealed that the number of AQPs in Xla genome nearly doubled that in Xtr (32 vs. 19). Synteny analysis indicated that the distribution of the retained AQPs in Xla subgenomes (17 in Xla. L, the longer homeolog of Xla genome and 15 in Xla. S, the shorter homeolog of Xla genome) were highly symmetrical when compared with that in Xtr genome. Remarkably, two members in Xla. L and four members in Xla. S were lost through evolution. Blast analysis revealed that the lost AQPs in Xla are pseudogenized via either the deletion of some exons or some single nucleotide insertions or deletions that lead the reading frame shift. Additionally, comparative genomic analyses suggested that the orthologs of AQPs that with one copy absence in Xla are also prone to be lost in higher vertebrates. Conclusion: This study revealed that polyploidization and subsequent pseudogenization and deletion in Xla genome promote the evolution of AQP family in higher vertebrates. Besides, our results would also contribute to understanding the evolution of AQP family.

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Background The diversified aquaporin (AQP) family that was derived from gene duplication and subsequent functional differentiation play critical roles in multiple physiological processes and in adaptation to the dynamic environments during the evolutionary process. Oysters are a group of bivalve fauna in Mollusca that were widely distributed around the world and show extraordinary adaptation to harsh environments. However, knowledge is lacking with the diversity and evolution of the AQP family in oysters, even in molluscs. Results Here, we performed a comprehensive analysis of the AQP family in three geographical isolated oyster species that are native to different environments. Genome distribution and phylogenetic analysis revealed that the expansion of the AQP family in oysters were attributed to tandem duplication. Synteny analysis indicated that large-scale inversions lead to the independent duplication or deletion of the AQPs after speciation. As a consequence, these independent duplication events contributed to the diversification of the AQP family in different oysters. Pore pattern analysis suggested that the duplicated AQPs in oysters were highly diversified in inner surface profiles, implying the subsequent functional differentiation. The comparison conducted based on the transcriptome data demonstrated that the functional differentiated AQP family members in oysters may play critical roles in maintaining the balance between the stationary homeostasis and dynamic environments. Conclusions Our observation provides evidence for the correlation between the duplicated and functional differentiated AQP family and the adaptation to stationary life under dynamic environments in oysters. Additionally, it also broadens our knowledge of the evolution of AQP family in molluscs.

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