Cloning and characterization of the LvCTL genes encoding C-type lectin from white-leg shrimp ( Litopenaeus vannamei).

Background: Lectins are carbohydrate-binding protein domains. The C-type lectin designates a requirement for calcium for binding. Proteins contain C-type lectin domains that have a diverse range of functions, including cell-cell adhesion, immune response to pathogens, and apoptosis. This study aimed to investigate the characters of LvCTL-encoding genes from white-leg shrimp ( Litopenaeus vannamei) in Central Vietnam. Methods: Two PCR products (LvCTL3 and LvCTL4) were cloned and sequenced. The structure and characterization of LvCTL proteins were predicted using bioinformatics tools. Results: The results showed that the LvCTL3 gene was 444 nucleotides in length and 98.87% similar to the published LvCTL3 gene (accession number: KF156943). The polypeptide sequence had 147 amino acids, which were 97.28% identical to the reference sequence (AGV68681) and the LvCTL4 gene had a length of 417 nucleotides and homology of 99.52% compared to the published gene (KM387560). The deduced polypeptide sequence had 138 amino acids, and was 100% similar to the reference sequence (AKA64754). The LvCTL3 had a molecular weight of 16.91 kDa and an isoelectric point (pI) of 4.66, while LvCTL4 had 15.75 and 4.58 kDa, respectively. The structure prediction results showed that LvCTL3 and LvCTL4 had one domain (CTLD), LvCTL3 had two α helices and nine ß sheets, and LvCTL4 had two α helices and eight ß sheets. Conclusions: Our results provide essential information for the heterologous expression and biosynthesis production of C-type lectins.

The identification and determination of toxin genes of Vibrio strains causing hemorrhagic disease on red drum (Sciaenops ocellatus) using PCR.

Data were collected from 30 strains of Vibrio and sampled on different organs (brain, hemorrhagic site and digestive tract) of Sciaenops ocellatus infection. The results showed that the nucleotide sequences 16S rRNA region are highly similar to those of V. alginolyticus, V. azureus, V. fluvialis, V. natriengens and V. orientalis, which were published on Genbank and other, ranging from 98.05 to 100%. The digestive tract has the most common Vibrio strains (V. alginolyticus [16] V. azureus [7] and V. fluvialis). Thereout, 25 of 30 strains of Vibrio contained 1 to 3 toxin genes, except V. parahaemolyticus. Six parameters were used to measure the DNA polymorphism of 33 homologous DNA sequences in this Vibrio bacteria population. The results indicated that number of separate polymorphic sites (S), total number of mutant sites (Eta), number of haplotype (h), haplotype diversity (Hd), average number of nucleotide differences (k), nucleotide diversity (Pi) were 98 (S), 103 (Eta), 9 (h), 0.887 ± 0.032 (Hd), 25.789 (k) and 17.980 × 10-3 ± 0.003 (Pi), respectively (P < 0,05). The G + C content above 1434 sites positions of nucleotide sequences accounted for 0.542. The phylogenetic tree showed that these strains are divided into six groups. As observed, the appearance of isolated Vibrio on 3 organs of fish (S. ocellatus) hemorrhagic are V. azureus (27,67%), V. alginolyticus (50%), V. orientalis (6,67%) and V. fluvialis (16,67%). Through this result, we found that the diversity of Vibrio species that appeared on the red drum was used in the 16S rRNA region and the presence of toxin genes in these Vibrio species.

Phylogenetic analysis of Anguilla marmorata population in Thua Thien Hue, Vietnam based on the cytochrome C oxidase I (COI) gene fragments.

The giant mottled eel is a species with high commercial value so overfishing, river management, and water pollution have negatively affected its movement and population numbers. Anguilla marmorata (eel) was listed in the Vietnam Red Data Book 2007 with a description of Vulnerability. This study used a barcode technique to analyze molecular characteristics and build genetic plants based on the cytochrome c oxidase I gene segment isolated from the mitochondrial genome of 48 individuals of A. marmorata collected in five different ecological regions of Thua Thien Hue, Vietnam. The isolated the cytochrome c oxidase I sequence has a length of 843 nucleotides, four base nucleotides of 30.03% Thymine, 25.15% Cytosine, 27.49% Adenine, and 17.43% Guanine. The percentage of Guanine + Cytosine content (42.58%) is acceptable, lower than the Adenine + Thymine content. The replacement capacity of Adenine and Guanine is 22.45% highest, the ratio between Thymine and Guanine; Cytosine and Guanine are the lowest at 2.72%. The establishment of genetically modified plants has shown the high genetic similarity of individuals in eel populations in Thua Thien Hue. The population of Anguilla marmorata eels in Thua Thien Hue, Vietnam is divided into two separate groups that are guided by the migration process and specific ecological. This is particularly important in building strategies to conserve and develop the gene for eel in Vietnam and Thua Thien Hue.