Analysis of the genetic diversity of the lymphocystis virus and its evolutionary relationship with its hosts.

Lymphocystis disease virus (LCDV) is the causative agent of lymphocystis disease. In this study, the mcp gene of LCDV and the cyt b gene of the host fish were selected as molecular markers, and the phylogenetic relationships between LCDV and its host were analyzed. The 25 LCDV isolates examined in this study were attributed to seven LCDV genotypes: genotype I (LCDV-1), genotype II (LCDV-cn, etc.), genotype III (LCDV-rf), genotype IV (LCDV-rc and LCDV-sb), genotype V (LCDV-cb), genotype VI (LCDV-tl), and genotype VII (LCDV-sa). Genotype VII is a new genotype. LCDV1 was found to have differentiated first, followed by LCDV-rf; then LCDV-tl; LCDV-cb; and then LCDV-sa; and by LCDV-rc and LCDV-sb; and finally by LCDV-cn, LCDV-C, and LCDV-jf. From the host evolutionary perspective, Rachycentron canadum was found to have differentiated first, followed by Trichogaster leeri, Chanda baculis, and Sebastes schlegeli, Lateolabrax sp., Sparus aurata, Platichthys flesus, and Paralichthys olivaceus. Comparison of the phylogenies of the host fish species and LCDVs revealed no significant evidence of cospeciation between LCDVs and their host fish. In-depth studies of the genetic variation in LCDVs can enhance our understanding of the mechanism of LCDV infection, which may provide important insights into the prevention and treatment of lymphocystis disease.

Contribution of the Akt2 gene to type 2 diabetes in the Chinese Han population.

BACKGROUND: The Akt2 protein kinase is thought to be a key mediator of the insulin signal transduction process. Akt2 is suggested to play a role in glucose metabolism and the development or maintenance of proper adipose tissue and islet mass. In order to determine whether the Akt2 gene plays a role in the pathogenesis of type 2 diabetes characterized by insulin resistance, and to further identify if variations in this gene have a relationship with type 2 diabetes, we sequenced the entire coding region and splice junctions of Akt2 and made a further case-control study to explore the association between single-nucleotide polymorphisms (SNPs) in this gene and type 2 diabetes in the Chinese Han population. METHODS: We selected 23 probands with a type 2 diabetic pedigree whose family members' average onset age was within 25 to 45 years old. The body mass index of all the participants was lower than 28 kg/m(2) and all of them were insulin-resistant (the fasting insulin level > 100 pmol/L or 16 µIU/ml). The entire coding region and splice junctions of Akt2 were directly sequenced in these 23 probands. SNPs with a frequency of minor allele over 20 percent were selected to be further studied in a case-control study. We chose 743 non-diabetic subjects as the control group and 742 type 2 diabetic patients as the case group. All these subjects were genotyped. A Snapshot Technology Platform (Applied Biosystems) was used for genotyping. RESULTS: The Akt2 genes from all 23 subjects were successfully sequenced. We did not identify any mutation in the type 2 diabetic pedigree. Two SNPs were identified, 13010323T > C and 13007939G > T. 13010323T > C was in intron 9, which was the location of rs2304188 reported in Genbank. Its minor allele frequency was 13.04%. 13007939G > T was in the 3'-untranslated region (UTR) of exon 14, which was the location of rs2304186 reported in Genbank. Its minor allele frequency was 34.78%. The allele frequency of rs2304188 and rs2304186 were consistent with the frequency reported in Genbank. In the case-control study with 742 patients and 743 controls, there was no significant difference between the two groups for the allele frequency of rs2304186 (odd ratio: 0.96, 95% confidence interval: 0.82 - 1.12, P = 0.597). CONCLUSIONS: The Akt2 gene is not a major cause of diabetes in a non-obese Chinese Han population characterized by insulin resistance. There is no significant relationship between rs2304186 and type 2 diabetes in the Chinese Han population.

Formation and oral administration of alginate microspheres loaded with pDNA coding for lymphocystis disease virus (LCDV) to Japanese flounder.

Oral delivery of plasmid DNA (pDNA) is a desirable approach for fish immunization in intensive culture. However, its effectiveness is limited because of possible degradation of pDNA in the fish's digestive system. In this report, alginate microspheres loaded with pDNA coding for fish lymphocystis disease virus (LCDV) and green fluorescent protein were prepared with a modified oil containing water (W/O) emulsification method. Yield, loading percent and encapsulation efficiency of alginate microspheres were 90.5%, 1.8% and 92.7%, respectively. The alginate microspheres had diameters of less than 10 microm, and their shape was spherical. As compared to sodium alginate, a remarkable increase of DNA-phosphodiester and DNA-phosphomonoester bonds was observed for alginate microspheres loaded with pDNA by Fourier transform infrared (FTIR) spectroscopic analysis. Agarose gel electrophoresis showed a little supercoiled pDNA was transformed to open circular and linear pDNA during encapsulation. The cumulative release of pDNA in alginate microspheres was or=0.3) for anti-LCDV antibody from week 3 to week 16 for fish orally vaccinated with alginate microspheres loaded with pDNA, in comparison with fish orally vaccinated with naked pDNA. Our results display that alginate microspheres obtained by W/O emulsification are promising carriers for oral delivery of pDNA. This encapsulation technique has the potential for DNA vaccine delivery applications due to its ease of operation, low cost and significant immune effect.