Phylogenetic diversity of dinoflagellates in polar regions

Because of the limitations of sampling and seasonal study in polar regions, knowledge of dinoflagellate diversity, distribution and ecology are limited. Dinoflagellates have been incidentally reported from polar regions during some seasons and some populations have been reported as components of microalgae. Surveys of molecular diversity link the genotype of dinoflagellates from polar regions with environmental adaptation. In this study, 37 positive clones of dinoflagellates collected from different sites were used for genotype analysis, providing new insights into the biodiversity and distribution of these species based on 18S rRNA sequencing. Diverse genotypes were recorded for the summer season in Kongsfjorden (high Arctic) whilst a single novel genotype of dinoflagellate was recorded from winter samples from the Antarctic Ocean. Data from ice cores suggests that this single dinoflagellate genotype was adapted to extreme cold and clone library screening found that it was occasionally the only microbial eukaryotic genotype found in winter ice cores. The findings of this study could improve our understanding of the diverse dinoflagellate genotypes occurring in these perennially cold microbial ecosystems

Inherent correlations between thermodynamics and statistic physics in extensive and nonextensive systems

With the help of a general expression of the entropies in extensive and nonextensive systems, some important relations between thermodynamics and statistical mechanics are revealed through the views of thermodynamics and statistic physics. These relations are proved through the MaxEnt approach once again. It is found that for a reversible isothermal process, the information contained in the first and second laws of thermodynamics and the MaxEnt approach is equivalent. Moreover, these relations are used to derive the probability distribution functions in nonextensive and extensive statistics and calculate the generalized forces of some interesting systems. The results obtained are of universal significance.Comment: 11 page

Purification and characterization of lectin from humoral fluids of Charybdis feriatus

【英文摘要】 To search new sources of lectin, an experiment on lectin distribution in humoral serum of crab Charybdis feriatus (in short, CFL) was conducted March, 2002. When adding solid ammonium sul-fate into the fluids up to 50% saturation at 4℃, most CFL activity showed precipitates who were then continually extracted by ammonium sulfate of different concentrations. The supernatant, which was called primary CFL fluids, was given a 17.60-fold purification and 45.70% recovery of total activity. Finally, by using Sepha...Supported by Project of Technology Bureau of Quanzhou of Fujian Province(Z200239) , and by the Fujian Natural Science Foundation (B0410027

Bid-overexpression regulates proliferation and phosphorylation of Akt and MAPKs in response to etoposide-induced DNA damage in hepatocellular carcinoma cells

National Natural Science Foundation of China [31071187, 81272721]; Fundamental Research Funds for the Central Universities [2010121102]; Xiamen Municipal Science and Technology Innovation Fund Project [3502Z20114018]; Program for New Century Excellent Talents in Fujian Province UniversityBackground: Growing evidence supports BH3-interacting domain death agonist (Bid) playing a dual role in DNA damage response. However, the effects of Bid on hepatocellular carcinoma (HCC) cell proliferation in response to etoposide-induced DNA damage have not been sufficiently investigated. Methods: Using a stable Bid-overexpression HCC cell line, Bid/PLC/PRF/5, overexpression of Bid promoted loss of viability in response to etoposide-induced DNA damage. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]- and BrdU (5'-bromo-2'-deoxyuridine)- labeling assays revealed that etoposide-inhibited HCC cells grew in concentration- and time-dependent manners. The phosphorylations of Akt and mitogen-activated protein kinases (MAPKs) in response to etoposide-induced DNA damage were analyzed by Western blotting. Results: The survival rates of 100 mu M etoposide on the cells with control vector and Bid/PLC/PRF/5 at 48 hours amounted to 71% +/- 0.75% and 59% +/- 0.60% with MTT assay, and similar results of 85% +/- 0.08% and 63% +/- 0.14% with BrdU-labeling assay respectively. Moreover, overexpression of Bid sensitized the cells to apoptosis at a high dose of etoposide (causing irreparable damage). However, it had little effect on the proliferation at a low dose of etoposide (repairable damage). Furthermore, the phosphorylation status of Akt and MAPKs were investigated. Overexpression of Bid suppressed the activation of Akt with respect to etoposideinduced DNA damage. Similar to Akt, the levels of phosphorylated p38 and phosphorylated c-Jun were attenuated by Bid-overexpression. On the contrary, the level of phosphorylated ERK1/2 was sustained at a high level, especially in Bid/PLC/PRF/5 cells. Conclusion: Taken together, these results suggest that overexpression of Bid suppressed the activation of Akt, p38, and c-Jun, and promoted the activation of ERK1/2 induced by etoposide, suggesting that the promotion of ERK1/2 activation may have a negative effect on Bid-mediated HCC DNA damage induced by etoposide

TCTP is a critical factor in shrimp immune response to virus infection.

The translationally controlled tumor protein (TCTP) is an abundant, ubiquitous, and conserved protein which plays important roles in a number of biological processes. In the present study, the TCTP in shrimp Litopenaeus vannamei was analyzed. The TCTP of L.vannamei, a 168-amino-acid polypeptide, shares a high degree of similarity with TCTPs from other species, having two TCTP protein signatures at the 45-55 aa and 123-145 aa motif. The mRNA and protein levels from different tissues were detected with the highest in muscle and the lowest in heart among all examined tissues. In addition, temporal TCTP expression was significantly up-regulated at 16 h and 48 h following infection with white spot syndrome virus (WSSV). Lastly, silencing of TCTP with dsRNA led to a significant increase of WSSV loads. These results provide new insights into the importance of TCTP as an evolutionarily conserved molecule for shrimp innate immunity against virus infection

Expression profiles of <i>L. Vannamei</i> TCTP.

<p>A) Relative expression of TCTP in different tissues of <i>Litopeaeus vannamei</i> determined by Real-time RT-PCR. Total RNA was extracted from haemocyte, heart, intestine, muscle, hepatopancreas, and gill of healthy shrimp respectively. B) Protein level of TCTP in different organs. Protein level was analyzed by Western blot. Loading of the lanes was normalized to levels of β-actin and the experiment is representative of five independent experiments.The calculated densitometry intensities of the respective bands were present as fold of β-actin. The results are expressed as means ± S.D (n = 5).</p

Temporal expression level of TCTP in gills after WSSV infection.

<p>A) Transcripts determined by real-time RT-PCR at different time post WSSV infection. B) TCTP protein level determined by Western blot. Loading of the lanes was normalized to levels of β-actin and the experiment is representative of three independent expriments. The calculated densitometry intensities of the respective bands were present as fold of β-actin. The results are expressed as means ± S.D (n = 3). The asterisk indicates that the expression levels are significantly different (P<0.05). C) Semi-quantitative RT-PCR expression profiles for transcripts encoding β-actin and VP28 of WSSV during time-course infection of WSSV.</p

Phylogenetic tree of the <i>L. vannamei</i> TCTP protein.

<p>The tree was constructed by the MEGA 4.0 program. Bootstrap analysis was performed using 1000 replicates to test the relative support for particular clades. Scale bar means evolutionary distance, and it was 0.1 million years.</p

Roles of TCTP in the shrimp immune response against WSSV infection.

<p>A) Shrimp were injected with TCTP, GFP dsRNA or NaCl. Gills from each shrimp were collected 48 h post challenge for real-time PCR to detect the specific of dsRNA. B) Shrimp were injected with TCTP, GFP dsRNA or NaCl every day for 4 days. At the second injection, WSSV (10⁴ copies/shrimp) and dsRNA were injected together. At 48 h post infection, the shrimp from each treatment were subjected to quantitative real-time PCR to quantify WSSV copies. C) WSSV VP28 transcripts were determined by real-time PCR. 1, 2, 3, 4 represent shrimps injected with NaCl, GFP dsRNA, 10 µg TCTP dsRNA and 20 µg TCTP dsRNA, respectively. The asterisk indicates the statistical significantly different (**P<0.01).</p

Characterization of <i>Litopeaeus vannamei</i> TCTP.

<p>A) The <i>Litopeaeus vannamei</i> TCTP ORF, the deduced amino acid sequence, and the motif analysis. The highly conserved TCTP signature 1 and 2 sequences are shown in bold italic letters. Four CK2-phospho-sites (casein kinase II phosphorylation site) are underlined. Two potential Asn-glycosylation sites are shown in textbox. B) TCTP alignment. The following species were aligned: <i>Homo sapiens</i> (NP_003286.1), <i>Mus musculus</i> (P14701), <i>Danio rerio</i> (NP_937783.1), <i>Scylla paramamosain</i> (ACY66461), <i>Penaeus monodon</i> (ACD13588.1), <i>Litopeaeus vannamei</i> (ABY55541.1), <i>Drosophila melanogaster</i> (AAF54603.1), <i>Fission yeast</i> (Q10344).</p