Detection and identification of antibiotic biosynthesis genes in Bacillus subtilis strains

Two Bacillus subtilis strains L10 and G1, previously isolated from fermented pickles, were tested for antibacterial activity against Vibrio harveyi using a well-diffusion agar assay. Antibiotic biosynthesis genes were then detected in both bacterial strains and included the following genes: bacA, bacB and bacD genes for bacilysin production, ppsE/fenB gene for plipastatin/fengycin production, albF and albA genes for subtilosin production, and srfAB and sfP genes for surfactin production. Based on these results, two B. subtilis strains could be considered as potential biological control agents in aquaculture.     

Revision of the genus Salganea St?l (Blattodea,Blaberidae, Panesthiinae) from China,with descriptions of three new species

Three new species of Salganea Stål, 1877 are described and illustrated: S. quinquedentata sp. n., S. anisodonta sp. n. and S. flexibilis sp. n. S. taiwanensis Roth, 1979, S. guangxiensis (Feng & Woo, 1990), S. incerta (Brunner von Wattenwyl, 1893) and S. raggei Roth, 1979 are redescribed. Panesthia concinna Feng & Woo, 1990 is synonymized with S. taiwanensis Roth, 1979 and Panesthia guangxiensis Feng & Woo, 1990 is transferred to the genus Salganea for the first time. As well, a key to species from China is presented.     

Retracted: Downregulation of long noncoding RNA H19 rescues hippocampal neurons from apoptosis and oxidative stress by inhibiting IGF2 methylation in mice with streptozotocin-induced diabetes mellitus

The diabetes mellitus (DM)-induced reduction of neurogenesis in the hippocampus is consequently accompanied by cognitive decline. The present study set out to define the critical role played by long noncoding RNA H19 (lncRNA H19) in the apoptosis of hippocampal neurons, as well as oxidative stress (OS) in streptozotocin (STZ)-induced DM mice through regulation of insulin-like growth factor 2 (IGF2) methylation. The expression of lncRNA H19 in the hippocampal neurons and surviving neurons were detected. Hippocampal neurons were cultured and transfected with oe-H19, sh-H19, oe-IGF2, or sh-IGF2, followed by detection of the expressions of IGF2 and apoptosis-related genes. Determination of the lipid peroxide and glutathione levels was conducted, while antioxidant enzyme activity was identified. The IGF2 methylation, the binding of lncRNA H19 to DNA methyltransferase, and the binding of lncRNA H19 to IGF2 promoter region were detected. DM mice exhibited high expressions of H19, as well as a decreased hippocampal neurons survival rate. Higher lncRNA H19 expression was found in DM. Upregulated lncRNA H19 significantly increased the expression of Bax and caspase-3 but decreased that of Bcl-2, thus promoting the apoptosis of hippocampal neuron. Besides, upregulation of lncRNA H19 induced OS. LncRNA H19 was observed to bind specifically to the IGF2 gene promoter region and promote IGF2 methylation by enriching DNA methyltransferase, thereby silencing IGF2 expression. Taken together, downregulated lncRNA H19 reduces IGF2 methylation and enhances its expression, thereby suppressing hippocampal neuron apoptosis and OS in STZ-induced (DM) mice.     

Populational Heterogeneity vs. Temporal Fluctuation in Escherichia coli Flagellar Motor Switching

The dynamic switching of the bacterial flagellar motor regulates cell motility in bacterial chemotaxis. It has been reported under physiological conditions that the switching bias of the flagellar motor undergoes large temporal fluctuations, which reflects noise propagating in the chemotactic signaling network. On the other hand, nongenetic heterogeneity is also observed in flagellar motor switching, as a large group of switching motors show different switching bias and frequency under the same physiological condition. In this work, we present simultaneous measurement of groups of Escherichia coli flagellar motor switching and compare them to long time recording of single switching motors. Consistent with previous studies, we observed temporal fluctuations in switching bias in long time recording experiments. However, the variability in switching bias at the populational level showed much higher volatility than its temporal fluctuation. These results suggested stable individuality in E. coli motor switching. We speculate that uneven expression of key regulatory proteins with amplification by the ultrasensitive response of the motor can account for the observed populational heterogeneity and temporal fluctuations.     

Modelling Immune System: Principles, Models,Analysis and Perspectives

The biological immune system is a complex adaptive system.There are lots of benefits for building the model of theimmune system.For biological researchers,they can test some hypotheses about the infection process or simulate the responsesof some drugs.For computer researchers,they can build distributed,robust and fault tolerant networks inspired by the functionsof the immune system.This paper provides a comprehensive survey of the literatures on modelling the immune system.Fromthe methodology perspective,the paper compares and analyzes the existing approaches and models,and also demonstrates thefocusing research effort on the future immune models in the next few years.     

Stimulation of photosynthesis and growth of photoautotrophically cultured plant cells by choline and its analogs

The effects of choline and its analogs, allylcholine and benzylcholine, on the photosynthesis and on the cell growth were examined using photoautotrophically, photomixotrophically and heterotrophically cultured cells. The addition of choline and its analogs stimulated the cellular photosynthetic activity and enhanced the dry weight increase in both photoautotrophic and photomixotrophic cells. However, the growth of heterotrophic cells did not increase by the addition of choline and choline analogs. The photosynthetic electron transport activity in thylakoid membrane was enhanced when cells were treated with choline and choline analogs, suggesting that thylakoid membranes are the initial site of the stimulation of cellular photosynthesis. The stimulatory effect of choline and choline analogs was sustained even after 3 week-culture. Among the choline analogs tested, benzylcholine showed the most quick effect and was effective at a lower concentration (1 mg/l) than choline (10 mg/l).Abbreviations GA₃ gibberellin A₃