Long-read transcriptomic analysis of orb-weaving spider Araneus ventricosus indicates transcriptional diversity of spidroins.

Spider silk, which is composed of diverse silk proteins (spidroin), is a kind of natural high-mass biomaterial with great potential. However, due to the complexity of both the structure and the composition of the spidroins in natural spider silk, application of this valuable biomass is still limited to date. There are diverse kinds of spider silk in the orb-weaving spider with different mechanical and structural characteristics. In order to systematically illustrate the landscape of all the different spidrons, here we chose Araneus ventricosus, an orb-weaving spider with superior silk mechanical features and genome information, to generate a long-read whole body transcriptome. We deciphered the repeat arrangements of each kind of spidroin, based on which we found that there are substantially transcriptional diversity of each spidroin gene. Some repeat motifs are not documented before. Specifically, we discovered novel full-lengh MaSp transcript as well as a relatively small full-length AcSp isoforms, which are potential promising materials for bioengineering of recombinant spidroin. Our study provided a batch of new spidron resources with detail sequential information. The finding of transcriptional diversity may provide cues in understanding of within-species variation of the mechanical properties of the natural spider silk and further molecular designing of recombinant spidroin.

Cancer cells arise from bacteria.

BACKGROUND: The origin of cancer cells is the most fundamental yet unresolved problem in cancer research. Cancer cells are thought to be transformed from the normal cells. However, recent studies reveal that the primary cancer cells (PCCs) for cancer initiation and secondary cancer cells (SCCs) for cancer progression are formed in but not transformed from the senescent normal and cancer cells, respectively. Nevertheless, the cellular mechanism of PCCs/SCCs formation is unclear. Here, based on the evidences (1) the nascent PCCs/SCCs are small and organelle-less resembling bacteria; (2) our finding that the cyanobacterium TDX16 acquires its algal host DNA and turns into a new alga TDX16-DE by de novo organelle biogenesis, and (3) PCCs/SCCs formations share striking similarities with TDX16 development and transition, we propose the bacterial origin of cancer cells (BOCC). PRESENTATION OF THE HYPOTHESIS: The intracellular bacteria take up the DNAs of the senescent/necrotic normal cells/PCCs and then develop into PCCs/SCCs by hybridizing the acquired DNAs with their own ones and expressing the hybrid genomes. TESTING THE HYPOTHESIS: BOCC can be confirmed by testing BOCC-based predictions, such as normal cells with no intracellular bacteria can not "transform" into cancer cells in any conditions. IMPLICATIONS OF THE HYPOTHESIS: According to BOCC theory: (1) cancer cells are new single-celled eukaryotes, which is why the hallmarks of cancer are mostly the characteristics of protists; (2) genetic changes and instabilities are not the causes, but the consequences of cancer cell formation; and (3) the common role of carcinogens, infectious agents and relating factors is inducing or related to cellular senescence rather than mutations. Therefore, BOCC theory provides new rationale and direction for cancer research, prevention and therapy.

Comparison of surgical and endovascular approaches in the management of multiple intracranial aneurysms.

OBJECTIVE: To investigate the outcomes and safety of endovascular compared with surgical clipping for multiple intracranial aneurysms. MATERIAL AND METHODS: 98 patients with 260 multiple intracranial aneurysms were treated with endovascular, surgical clipping, combined treatment, and observation. Data were retrospectively studied following treatment and at follow-up. RESULTS: In the endovascular group, 44 aneurysms were treated with coils only and 29 aneurysms were treated with stent deployment. The complete occlusion rate was 65%, and the total complication rate was 12% with no permanent deficit. After angiographic follow-up for 1-90 (mean 62) months, the total recurrence rate was 18.3%. In the clipping group, 65 aneurysms were clipped. The complete occlusion rate was 90.8%, and the complication rate was 10.9% with 1 permanent deficit. After follow-up for 11-71 (mean 49) months, the angiographic recurrence rate was 1.5%. In the combination group, 20 aneurysms were treated endovascularly. The complete occlusion rate was 78.9%, and the complication rate was 15.8% with no permanent deficit. Twenty-eight aneurysms were treated surgically with the complete occlusion rate of 89.3%, the complication rate of 20% and 3 permanent deficits. After follow-up for 1-93 (mean 58) months, the angiographic recurrence rate was 33.3% for embolization and 3.6% for clipping. Seventy-four aneurysms for observation had 2.7% regrowth rate within 1-3 years. CONCLUSION: Endovascular embolization has an accepted complication rate but no neurological deficits compared with surgical clipping and may be a better approach for multiple intracranial aneurysms than surgical clipping.

Isolation,Identification and Characterization of Thiosulfate-oxidizing Bacterium TX / 微生物学通报

A thiosulfate-oxidizing bacterium TX was isolated from polysulfide wastewater treatment system.It was preliminarily identified as Halothiobacillus sp.according to its morphological,physiological proper-ties and similarity analysis of 16S rRNA gene sequence(GenBank accession No.EU871645).This bacte-rium was an obligate chemolithoautotrophic sulfur-oxidizing bacterium since it could utilize thiosulfate,elemental sulfur,tetrathionate,sulfide or sulfite as sole energy source but did not show growth on the me-dium with glucose,sucrose,fructose,lactose,mannose or yeast extract as sole carbon source.The optimal growth condition for thiosulfate oxidation was 30?C~35?C and pH 3.0~5.0 respectively.Significant reduc-tion in medium pH from 4.0 to 1.2 was observed due to oxidation of thiosulfate to sulfate during the batch culture incubation period.During the course of thiosulfate oxidation accumulation of tetrathionate was ob-served either in synthetic medium or in the mixed liquor from aeration tank of the polysulfide wastewater treatment system.This indicates that the "S4 intermediate(S4I)" pathway was responsible for thiosulfate oxidation in this bacterium.

Metabolic flux analysis of the two astaxanthin-producing microorganisms Haematococcus pluvialis and Phaffia rhodozyma in the pure and mixed cultures.

The two major astaxanthin-producing microorganisms Phaffia rhodozyma and Haematococcus pluvialis exhibited elevated astaxanthin yields under the mixed culture regime, and the changes in flux distribution were investigated by means of metabolic flux analysis (MFA). In the mixed culture of the two strains, the carbon flux towards astaxanthin formation in P. rhodozyma increased by 20%, which may be due to the enriched oxygen evolved through the photosynthesis of H. pluvialis. On the other hand, the uptake of pyruvate and CO(2) excreted by P. rhodozyma also facilitated astaxanthin synthesis in H. pluvialis, which reduced 33% of the carbon flux exported from Calvin cycle to the catabolic pathway, and in turn raised the carbon flux to glyceraldehyde-3-phosphate by 25%. As a result, the carbon flux diverted to astaxanthin synthesis increased 2.8-fold in comparison with that in the pure culture.

[Association between the polymorphism of beta-fibrinogen gene -455G/A and ischemic stroke].

OBJECTIVE: To study the association between the variation of beta fibrinogen gene promoter -455G/A and ischemic stroke. METHODS: Eighty-six hypertensive patients with ischemic stroke (stroke group) and 85 hypertensive patients without ischemic stroke (hypertensive group) were randomly selected from the in patients, and 90 healthy persons(control group) were recruited for this study. Polymerase chain reaction with restrictive enzyme Hae III (PCR-restriction fragment length polymorphism method) was employed to analyze the polymorphism of beta-fibrinogen gene promoter -455G/A. Plasma fibrinogen levels were measured with prothrombin time (PT) assay. RESULTS: A(-455) allele frequencies of the stroke group (0.22) was significantly higher than that of the control group and the hypertensive group (0.11, 0.13, chi-square=8.3 P<0.05). The genotype exhibited significant difference among the 3 groups; G/A and A/A were more commonly seen in the stroke group(chi-square=10.03,P<0.05). The mean fibrinogen level of the stroke group(4.82+/-0.26 g/L) was significantly higher than that of the control group and the hypertensive group(4.37+/-0.19, 5.50+/-0.20, F=5.98 P<0.01) In both stroke group and hypertensive group, the plasma fibrinogen levels in patients with -455G/G were significantly lower than those in patients with -455G/A, and -455A/A but the difference was not significant among the 3 genotypes in the control group. CONCLUSION: Plasma fibrinogen level could be affected by the beta-fibrinogen gene -455G/A polymorphism. And A(-455) allele may be an independent risk factor for ischemic stroke.