Functional investigation of AfsKRS regulatory system for pristinamycin biosynthesis in .

Three genes encoding AfsK, AfsR, AfsS homologues in were studied, respectively, to investigate regulatory role of AfsKRS system for pristinamycin biosynthesis. Transcription change and gene inactivation analysis indicated that these genes had active transcription and positive regulation for the improvement of pristinamycin production in . The analysis of AfsKRS-defective mutagenesis indicated that there might be a positive correlation between the product of and pristinamycin I biosynthesis, and a negative correlation to pristinamycin II biosynthesis.

A novel carbonyl reductase with anti-Prelog stereospecificity for the production of -butyl 6-cyano-(3, 5)-dihydroxyhexanoate.

A novel gene () from was cloned and then overexpressed in a recombinant strain BL21(DE3)/pET30a-crc1 of . The resulting carbonyl reductase was prepared through fermentations using the recombinant strain. The purified enzyme showed an NADPH-dependent activity and specific activity was 4.

Sex-related differences in resting-state brain activity and connectivity in the orbital frontal cortex and insula in patients with functional constipation.

Functional magnetic resonance imaging (fMRI) has been used to investigate sex-related differences in brain abnormalities in patients with irritable bowel syndrome (IBS). Like IBS, women with functional constipation (FC) are 2.1 times as many as men.

Reduced plasma ghrelin concentrations are associated with decreased brain reactivity to food cues after laparoscopic sleeve gastrectomy.

The "hunger" hormone ghrelin regulates food-intake and preference for high-calorie (HC) food through modulation of the mesocortico-limbic dopaminergic pathway. Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric surgery to treat morbid obesity. We tested the hypothesis that LSG-induced reductions in appetite and total ghrelin levels in blood are associated with reduced prefrontal brain reactivity to food cues.

Bariatric surgery in obese patients reduced resting connectivity of brain regions involved with self-referential processing.

Obese individuals exhibit brain alterations of resting-state functional connectivity (RSFC) integrity of resting-state networks (RSNs) related to food intake. Bariatric surgery is currently the most effective treatment for combating morbid obesity. How bariatric surgery influences neurocircuitry is mostly unknown.

Structural changes in brain regions involved in executive-control and self-referential processing after sleeve gastrectomy in obese patients.

Obesity-related brain gray (GM) and white matter (WM) abnormalities have been reported in regions associated with food-intake control and cognitive-emotional regulation. Bariatric surgery (BS) is the most effective way to treat obesity and induce structural recovery of GM/WM density and WM integrity. It is unknown whether the surgery can promote structural changes in cortical morphometry along with weight-loss.

Ghrelin reductions following bariatric surgery were associated with decreased resting state activity in the hippocampus.

Background/objective: Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric surgery to treat obesity, and involves removal of the gastric fundus where ghrelin is mainly produced. Ghrelin stimulates appetite and regulates food intake through its effect on the hypothalamus and hippocampus (HIPP). While ghrelin's role on the hypothalamus has been explored, little is known about its role on HIPP.

Disrupted topological organization of the frontal-mesolimbic network in obese patients.

Neuroimaging studies have revealed brain functional abnormalities in frontal-mesolimbic regions in obesity. However, the effects of obesity on brain network topology remains largely unknown. In the current study, we employed resting-state functional magnetic resonance imaging and graph theory methods to investigate obesity-related changes in brain network topology in 26 obese patients and 28 normal weight subjects.

Complexity of roles and regulation of the PMK1-MAPK pathway in mycelium development, conidiation and appressorium formation in Magnaporthe oryzae.

MST50, MST11, MST7, PMK1 and GAS1/GAS2 genes are the important components in the PMK1-MAPK signal transduction pathway in fungi. Mutants with deletion of these five genes of Magnaporthe oryzae, a pathogen of the rice blast, were constructed. A cDNA array containing 4108 unique genes of M.

Probing the molecular mechanisms for pristinamycin yield enhancement in Streptomyces pristinaespiralis.

The mechanisms for the enhancement of pristinamycin production in the high-yielding recombinants of Streptomyces pristinaespiralis obtained by genome shuffling were investigated by quantitative real-time PCR (Q-PCR) and amplified fragment length polymorphism (AFLP) techniques. Q-PCR analysis showed that snaB and snbA involved, respectively, in the biosynthesis of pristinamycins II and I component had more extended high expression in the recombinant than that in the ancestor during fermentation process, indicating their expression changes might be key factors during the biosynthesis of the antibiotic. In addition, the antecedent establishment of the high self-resistance to pristinamycin, because ptr resistance gene started high-level expression ahead of the onset of the antibiotic production in the recombinant, might also lead to the increase of the antibiotics yield.

Isolation and functional analysis of spy1 responsible for pristinamycin yield in Streptomyces pristinaespiralis.

A gene related to high pristinamycin yield in Streptomyces pristinaespiralis was selected by amplified fragment length polymorphism (AFLP) and its functions were investigated by gene disruption. First, a 561 bp polymorphic sequence was acquired by AFLP from high-yield recombinants compared with the S. pristinaespiralis ancestor ATCC25486, indicating that this approach is an effective means of screening for valuable genes responsible for antibiotic yield.

Conjugal transferring of resistance gene ptr for improvement of pristinamycin-producing Streptomyces pristinaespiralis.

Improving pristinamycin production from Streptomyces pristinaespiralis was performed by introducing the resistance gene ptr followed by selection for enhanced tolerance to pristinamycin and fermentation test. To transfer ptr into S. pristinaespiralis, an effective method was established for the first time by using the intergeneric conjugation of DNA from Escherichia coli to S.

Evolution of Streptomyces pristinaespiralis for resistance and production of pristinamycin by genome shuffling.

Improvement of pristinamycin production by Streptomyces pristinaespiralis was performed by using recursive protoplast fusion and selection for improved resistance to the product antibiotic in a genome shuffling format. A 100-microg/ml pristinamycin resistant recombinant, G 4-17, was obtained after four rounds of protoplast fusion, and its production of pristinamycin reached 0.89 g/l, which was increased by 89.

Genomic variability among high pristinamycin-producing recombinants of Streptomyces pristinaespiralis revealed by amplified fragment length polymorphism.

Amplified fragment length polymorphism (AFLP) was used to analyze genomic variability between high pristinamycin-producing recombinants of Streptomyces pristinaespiralis produced by genome shuffling and their ancestral strain. The AFLP fingerprints obtained with two restriction enzyme combinations of ApaI/TaqI and PstI/SacII showed together that there was no major polymorphism (less than 10%) between these high yield recombinants and their ancestor. However, the unique polymorphic bands, which might be related to the yield increasing of pristinamycin, could be distinguished from all the recombinants.

Application of cDNA array for studying the gene expression profile of mature appressoria of Magnaporthe grisea.

Appressorium is an infection structure of the phytopathogenic fungus Magnaporthe grisea. Analysis of gene expression profiles of appressorium development provides insight into the molecular basis of pathogenicity and control of this fungal plant disease. A cDNA array representing 2927 unique genes based on a large EST (expressed sequence tag) database of M.

Analysis of expressed sequence tag data and gene expression profiles involved in conidial germination of Fusarium oxysporum.

We obtained 3,372 tentative unique transcripts (TUTs) from a cDNA library of Fusarium oxysporum. A cDNA array with 3,158 TUTs was produced to analyze gene expression profiles in conidial germination. It seems that ras and other signaling genes, e.