Genetic diversity of the endangered species Kirengeshoma palmata (Saxifragaceae) in China

In order to investigate the levels of genetic diversity of the endangered species Kirengeshoma palmata (Saxifragaceae), four extant populations were sampled and analyzed using inter-simple sequence repeats (ISSR) markers. We expected a low genetic diversity level, but our results revealed a high level of intraspecific genetic diversity, probably resulting from this species being in a refuge during the last glaciation (at population level: P = 63.25%, A_e = 1.47, H_E = 0.26 and H_O = 0.37; at species level: P = 79.00%, A = 1.5538, H_T = 0.2586 and H_sp = 0.3104). A low level of genetic differentiation among populations was detected based on Nei's genetic diversity analysis (16.69%) and AMOVA (19.36%). Populations shared high levels of genetic identity. Insect pollination and seed dispersal by wind may have facilitated extensive gene flow and are likely responsible for this present structure of genetic variation.     

Reduced Regional Homogeneity in Bilateral Frontostriatal System Relates to Higher Impulsivity Behavior in Codeine-Containing Cough Syrups Dependent Individuals

Background

In the past twenty years, codeine-containing cough syrups (CCS) was recognized as a new type of addictive drugs. However, the exact neurobiologic mechanisms underlying CCS-dependence are still ill-defined. The aims of this study are to identify CCS-related modulations of neural activity during the resting-state in CCS-dependent individuals and to investigate whether these changes of neural activity can be related to duration of CCS use, the first age of CCS use and impulse control deficits in CCS-dependent individuals. We also want to observe the impact of gray matter deficits on these functional results.

Methodology/Principal Findings

Thirty CCS-dependent individuals and 30 control subjects participated. Resting-state functional MRI was performed by using gradient-echo echo-planar imaging sequence. Regional homogeneity (ReHo) was calculated by using REST software. Voxel-based analysis of the ReHo maps between controls and CCS-dependent groups was performed using two-sample t tests (p<0.05, corrected for multiple comparisons). The Barratt Impulsiveness Scale 11 (BIS.11) was surveyed to assess participants'' impulsivity trait soon after MR examination. Abnormal clusters revealed by group comparison were extracted and correlated with impulsivity, duration of CCS use, and age of first CCS use. ReHo was diminished in the bilateral medial orbitofrontal cortex (mOFC) and left dorsal striatum in CCS-dependent individuals. There were negative correlations between mean ReHo in the bilateral medial OFC, left dorsal striatum and duration of CCS use, BIS.11 total scores, and the subscale of attentional impulsivity in CCS-dependent individuals. There was a significantly positive correlation between mean ReHo in the left dorsal striatum and age of first CCS use in CCS-dependent individuals. Importantly, these results still remain significant after statistically controlling for the regional gray matter deficits.

Conclusion

Resting-state abnormalities in CCS-dependent individuals revealed in the present study may further improve our understanding about the neural substrates of impulse control dysfunction in CCS-dependent individuals.     

紫菜外生细菌抑菌活性及其多聚酮合酶(PKS Ⅰ)基因筛选

[目的]基于紫菜外生细菌抑菌活性的研究,本文对具有广谱抑菌活性的菌株进行了多聚酮合酶(Polyketide synthase Ⅰ,PKS Ⅰ)基因的筛选,以期获得PKS Ⅰ阳性菌株及探讨紫菜藻际微生物区系细菌的拮抗机制与PKS Ⅰ途径的关系.[方法]利用琼脂柱法筛选出具广谱抑菌活性的菌株31株,以其基因组DNA为模板,设计引物扩增酮基合成酶(Ketosynthase, KS)片段基因并将其克隆到pMD19-T Vector,筛选出PKS Ⅰ阳性菌,进行16S rDNA测序分析.[结果]紫菜外生细菌表现出广谱抑菌性.从温州病烂紫菜外生菌中筛选出3株具强抑菌活性的PKS Ⅰ阳性菌,BLAST比对结果显示:菌株WPhG3、WPySw1和WPySw2扩增得到PKS Ⅰ的KS结构域核苷酸序列所对应的氨基酸序列与Bacillus subtilis subsp. subtilis str. 168(NP. 389602)、Bacillussubtilis (ABR19776)和Aspergillus carbonarius(AAZ99721)的PKS Ⅰ的KS结构域的同源性分别达到98%、99%和98%;16S rDNA系统发生学分析显示它们均与Bacillus的同源性最高.[结论]紫菜藻际微生物群落组成复杂,通过多条途径调节藻际微生物区系的平衡.PKS Ⅰ途径可能是温州病烂紫菜外生菌Bacillus表现抑菌活性的一种方式.     

Development and characterization of 33 polymorphic microsatellite markers in Trachurus japonicus by SLAF-seq technology

Trachurus japonicus is an economically important fish in the northwestern Pacific Ocean. However, its resources have declined seriously and there is an urgent need for a wide-range of investigations of the existing genetic resources. This requires a large number of diverse molecular markers with high discriminating power. In this study, we identified 43,264 perfect SSRs in T. japonicus genome using SLAF-seq technology. Of these, we randomly selected 106 SSRs (tri-nucleotide to hexa-nucleotide) to test for polymorphism. Eventually, we successfully developed a total of 33 loci including 8 tri-nucleotide and 25 long repeat motifs (tetra-nucleotide to hexa-nucleotide). The number of alleles (Na) of these loci ranged from 4 to 24 (mean 12.6). The observed heterozygosity (Ho) and expected heterozygosity (He) varied from 0.258 to 0.969 (mean 0.723) and from 0.452 to 0.962 (mean 0.827), respectively. All loci except TJ6-7 were highly informative (PIC > 0.5). These results showed that the shortlisted 33 loci exhibited moderate to relatively high genetic diversity, of which 18 were regarded as highly polymorphic and well-resolved. In summary, these diverse and potential microsatellites detected in our study provide substantial genetic basis for the screening of polymorphic SSR markers of T. japonicus and also provide a powerful tool to perform further studies on the genetic resource assessment and conservation of T. japonicus.     

LncRNA TP73-AS1 enhances the malignant properties of pancreatic ductal adenocarcinoma by increasing MMP14 expression through miRNA -200a sponging

Pancreatic ductal adenocarcinoma (PDAC) is an invasive and aggressive cancer that remains a major threat to human health across the globe. Despite advances in cancer treatments and diagnosis, the prognosis of PDAC patients remains poor. New and more effective PDAC therapies are therefore urgently required. In this study, we identified a novel host factor, namely the LncRNA TP73-AS1, as overexpressed in PDAC tissues compared to adjacent healthy tissue samples. The overexpression of TP-73-AS1 was found to correlate with both PDAC stage and lymph node metastasis. To reveal its role in PDCA, we targeted TP73-AS1 using LnRNA inhibitors in a range of pancreatic cancer (PC) cell lines. We found that the inhibition of TP73-AS1 led to a loss of MMP14 expression in PC cells and significantly inhibited their migratory and invasive capacity. No effects of TP73-AS1 on cell survival or proliferation were observed. Mechanistically, we found that TP73-AS1 suppressed the expression of the known oncogenic miR-200a. Taken together, these data highlight the prognostic potential of TP73-AS1 for PC patients and highlight it as a potential anti-PDAC therapeutic target.     

Deficiency of Macf1 in osterix expressing cells decreases bone formation by Bmp2/Smad/Runx2 pathway

Microtubule actin cross‐linking factor 1 (Macf1) is a spectraplakin family member known to regulate cytoskeletal dynamics, cell migration, neuronal growth and cell signal transduction. We previously demonstrated that knockdown of Macf1 inhibited the differentiation of MC3T3‐E1 cell line. However, whether Macf1 could regulate bone formation in vivo is unclear. To study the function and mechanism of Macf1 in bone formation and osteogenic differentiation, we established osteoblast‐specific Osterix (Osx) promoter‐driven Macf1 conditional knockout mice (Macf1^f/fOsx‐Cre). The Macf1^f/fOsx‐Cre mice displayed delayed ossification and decreased bone mass. Morphological and mechanical studies showed deteriorated trabecular microarchitecture and impaired biomechanical strength of femur in Macf1^f/fOsx‐Cre mice. In addition, the differentiation of primary osteoblasts isolated from calvaria was inhibited in Macf1^f/fOsx‐Cre mice. Deficiency of Macf1 in primary osteoblasts inhibited the expression of osteogenic marker genes (Col1, Runx2 and Alp) and the number of mineralized nodules. Furthermore, deficiency of Macf1 attenuated Bmp2/Smad/Runx2 signalling in primary osteoblasts of Macf1^f/fOsx‐Cre mice. Together, these results indicated that Macf1 plays a significant role in bone formation and osteoblast differentiation by regulating Bmp2/Smad/Runx2 pathway, suggesting that Macf1 might be a therapeutic target for bone disease.     

大耳猬血液、尿无机离子等指标测定及肾脏水通道蛋白1、2的表达

测定了大耳猬血清及尿中多种无机离子和尿素氮等指标,并应用免疫组织化学方法观察了AQP1、AQP2在肾脏的表达.大耳猬血清钠、氯含量较高;而尿液中以钾、钠、氯及尿素氮含量较高.尿液中主要离子浓度高于血清,较为浓缩,尿素氮、钾排泄能力较强.AQP1免疫反应阳性表达于近曲小管上皮和髓袢细段,AQP2主要表达于集合管上皮细胞.因此,AQP1、AQP2可能在大耳猬肾脏水重吸收及尿液浓缩过程中具有重要作用.     

Global transcriptional analysis of stress-response strategies in Acidithiobacillus ferrooxidans ATCC 23270 exposed to organic extractant—Lix984n

Acidithiobacillus ferrooxidans (A. ferrooxidans) ATCC 23270 is a model bacteria for bioleaching research. Because of the use of extractant in metal extraction industry, A. ferrooxidans needs to cope with the water-organic two-phase system. To get insight into the molecular response of A. ferrooxidans to organic solvent, global gene expression pattern was examined in A. ferrooxidans ATCC 23270 cells subjected to Lix984n (an organic extractant) using the method of whole-genome DNA microarray. The data suggested that the global response of A. ferrooxidans to Lix984n stress was characterized by the up-regulation of genes involved in pentose phosphate pathway, fatty acid and glutamate biosynthesis. In further study, compared to heterotrophic bacteria in dealing with short-time stress, A. ferrooxidans has a special strategy of continuously enhancing the expression of genes encoding proteins involved in electron transport, such as petI, petII, cyo and cyd. Besides, acrAB-tolC operon encoding organic solvent efflux pump and its positive regulator gene ostR were addressed.     

Ethanol induced the formation of β‐sheet and amyloid‐like fibrils by surfactant‐like peptide A6K

Self‐assembly of natural or designed peptides into fibrillar structures based on β‐sheet conformation is a ubiquitous and important phenomenon. Recently, organic solvents have been reported to play inductive roles in the process of conformational change and fibrillization of some proteins and peptides. In this study, we report the change of secondary structure and self‐assembling behavior of the surfactant‐like peptide A6K at different ethanol concentrations in water. Circular dichroism indicated that ethanol could induce a gradual conformational change of A6K from unordered secondary structure to β‐sheet depending upon the ethanol concentration. Dynamic light scattering and atomic force microscopy revealed that with an increase of ethanol concentration the nanostructure formed by A6K was transformed from nanosphere/string‐of‐beads to long and smooth fibrils. Furthermore, Congo red staining/binding and thioflavin‐T binding experiments showed that with increased ethanol concentration, the fibrils formed by A6K exhibited stronger amyloid fibril features. These results reveal the ability of ethanol to promote β‐sheet conformation and fibrillization of the surfactant‐like peptide, a fact that may be useful for both designing self‐assembling peptide nanomaterials and clarifying the molecular mechanism behind the formation of amyloid fibrils. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.