Emergence of breeding tubercles and puberty onset in male zebrafish: evidence for a dependence on body growth

The presence of breeding tubercles (BTs) on the pectoral fins has been investigated as a typical male secondary sexual characteristic (SSC) that distinguish males from females in adult zebrafish. Nonetheless, the earliest occurrence of these tubercles and its association with puberty onset and body growth remain unclear. In this study, using morphological, histological and statistical analyses, the authors examined the first appearance of BTs and puberty onset in male zebrafish, with particular emphasis on the potential impact of body growth on them. The results of this study revealed that BTs distributed along the first five branched pectoral fin rays were the earliest manifestation of male SSCs, which is significantly strongly correlated with body weight (R² = 0.9609, P < 0.001), and could be used as a “gold standard” for the earliest sex distinction (<0.1 g in weight). Using the first appearance of BTs (<0.20 mm²) as a metric, the authors established that male puberty commenced at a body weight of c. 0.056 ± 0.015 g or a standard length of 10.99 ± 1.051 mm (mean ± S.D. ). In this study, the authors thus established a simple method that can be used to sex live zebrafish at the pubertal stage and provides the first evidence for the relationship of BTs and male puberty initiation with body growth. These findings will accordingly lay a foundation for exploring mechanisms of the SSCs and male puberty onset in zebrafish and other teleost fish.     

Evidence that exogenous urea acts as a potent cue to alleviate ammonium‐inhibition of root system growth of cotton plant (Gossypium hirsutum)

Many plants grown with low‐millimolar concentration of NH₄⁺ as a sole nitrogen source develop NH₄⁺‐toxicity symptoms. To date, crucial molecular identities and a practical approach involved in the improvement of plant NH₄⁺‐tolerance remain largely unknown. By phenotyping of upland cotton grown on varied nitrogen forms, we came across a phenomenon that caused sub‐millimolar concentrations of urea (e.g., up 50 μM) to repress the growth inhibition of roots and whole plant cultivated in a NH₄⁺‐containing nutrient solution. A growth‐recovery assay revealed that the relief in NH₄⁺‐inhibited growth required only a short‐term exposure (≧12 h) of the roots to urea, implying that urea could elicit an internal signaling and be involved in antagonizing NH₄⁺‐sensitivity. Intriguingly, split‐root experiments demonstrated that low urea occurrence in one root‐half could efficaciously stimulate not only supplied root but also the root‐half grown in NH₄⁺‐solution without urea, indicating the existence of urea‐triggered local and systemic long‐distance signaling. In the split‐root experiment we also observed high arginase activity, strong arginine reduction and remarkable upregulation of polyamine biosynthesis‐related genes (ADC1/2, SPDS and SPMS). Therefore, we suggest that external urea might serve as an effective cue (signal molecule) in an arginine‐/polyamine‐related process for ameliorating NH₄⁺‐suppressed root growth, providing a novel aspect for deeper exploring and understanding plant NH₄⁺‐tolerance.     

奥利万星中间体A82846B产生菌拟孢囊菌CCTCC M2020063全基因组序列分析与mbtH类基因的验证

[目的] 分析荒漠拟孢囊菌CCTCC M2020063中A82846B合成的代谢途径和关键基因。[方法] 使用Illumina二代测序和PacBio三代测序技术对荒漠拟孢囊菌CCTCC M2020063进行全基因组测序,利用Glimmer预测编码序列,使用HPLC和LCMS鉴定次级代谢产物,使用antiSMASH 5.0软件预测次级代谢产物合成基因簇。利用Geneious软件对A82846B合成相关基因进行分析,对其中的mbtH类基因着重分析。[结果] 本实验菌株鉴定为荒漠拟孢囊菌（Kibdelosporangium aridum）,基因组中有一条线性染色体,无质粒,序列全长12475688 bp,GC含量为66.27%,有11900个开放阅读框,共有47个基因簇。该菌株具有合成A82846B的能力,且生物合成相关基因位于Cluster32,包含33个基因,mbtH类基因gene07864的过表达促进A82846的合成,提升了26.42%,卤化酶基因为gene07859,与万古霉素、巴利霉素的卤化酶相似度较高。[结论] 本研究对荒漠拟孢囊菌CCTCC M2020063进行了基因组序列分析,获得了A82846B生物合成相关的功能基因信息,为A82846B的代谢途径和工程改造提供了强有力的基础。     

The Arabidopsis AGC kinases NDR2/4/5 interact with MOB1A/1B and play important roles in pollen development and germination

Pollen formation and pollen tube growth are essential for the delivery of male gametes into the female embryo sac for double fertilization. Little is known about the mechanisms that regulate the late developmental process of pollen formation and pollen germination. In this study, we characterized a group of Arabidopsis AGC kinase proteins, NDR2/4/5, involved in pollen development and pollen germination. The NDR2/4/5 genes are mainly expressed in pollen grains at the late developmental stages and in pollen tubes. They function redundantly in pollen formation and pollen germination. At the tricellular stages, the ndr2 ndr4 ndr5 mutant pollen grains exhibit an abnormal accumulation of callose, precocious germination and burst in anthers, leading to a drastic reduction in fertilization and a reduced seed set. NDR2/4/5 proteins can interact with another group of proteins (MOB1A/1B) homologous to the MOB proteins from the Hippo signaling pathway in yeast and animals. The Arabidopsis mob1a mob1b mutant pollen grains also have a phenotype similar to that of ndr2 ndr4 ndr5 pollen grains. These results provide new evidence demonstrating that the Hippo signaling components are conserved in plants and play important roles in sexual plant reproduction.     

iGPCR-Drug: A Web Server for Predicting Interaction between GPCRs and Drugs in Cellular Networking

Involved in many diseases such as cancer, diabetes, neurodegenerative, inflammatory and respiratory disorders, G-protein-coupled receptors (GPCRs) are among the most frequent targets of therapeutic drugs. It is time-consuming and expensive to determine whether a drug and a GPCR are to interact with each other in a cellular network purely by means of experimental techniques. Although some computational methods were developed in this regard based on the knowledge of the 3D (dimensional) structure of protein, unfortunately their usage is quite limited because the 3D structures for most GPCRs are still unknown. To overcome the situation, a sequence-based classifier, called “iGPCR-drug”, was developed to predict the interactions between GPCRs and drugs in cellular networking. In the predictor, the drug compound is formulated by a 2D (dimensional) fingerprint via a 256D vector, GPCR by the PseAAC (pseudo amino acid composition) generated with the grey model theory, and the prediction engine is operated by the fuzzy K-nearest neighbour algorithm. Moreover, a user-friendly web-server for iGPCR-drug was established at http://www.jci-bioinfo.cn/iGPCR-Drug/. For the convenience of most experimental scientists, a step-by-step guide is provided on how to use the web-server to get the desired results without the need to follow the complicated math equations presented in this paper just for its integrity. The overall success rate achieved by iGPCR-drug via the jackknife test was 85.5%, which is remarkably higher than the rate by the existing peer method developed in 2010 although no web server was ever established for it. It is anticipated that iGPCR-Drug may become a useful high throughput tool for both basic research and drug development, and that the approach presented here can also be extended to study other drug – target interaction networks.     

Hypoxia Promotes Epithelial - Mesenchymal Transition of Hepatocellular Carcinoma Cells via Inducing GLIPR-2 Expression

Glioma pathogenesis related-2 (GLIPR-2) belongs to pathogenesis related-1 (PR-1) family whose function remains unknown. In our previous studies, GLIPR-2 was found to be a novel potent stimulator of epithelial-to-mesenchymal transition (EMT) in renal fibrosis which has been classified as type 2 EMT. However, whether GLIPR-2 could induce type 3 EMT in carcinogenesis needs further investigation. In this study, we showed that GLIPR-2 was expressed in hepatocellular carcinoma (HCC) tissues, hypoxia could upregulate the expression of GLIPR-2 in HepG2 and PLC/PRF/5 cells in vitro, overexpression of this protein promoted migration and invasion via EMT, knockdown of GLIPR-2 attenuated migration and invasion of HepG2 and PLC/PRF/5 cells in hypoxia. Moreover, extracellular signal-regulated kinases 1 and 2 (ERK1/2) are positively regulated by GLIPR-2. Taken together, we provide evidence for a hypoxia/GLIPR-2/EMT/migration and invasion axis in HCC cells and it provides novel insights into the mechanism of migration and invasion of hepatocellular carcinoma cells in hypoxia condition.     

Identification of a Novel TECTA Mutation in a Chinese DFNA8/12 Family with Prelingual Progressive Sensorineural Hearing Impairment

Tectorial membrane, an extracellular matrix of the cochlea, plays a crucial role in the transmission of sound to the sensory hair cells. Alpha-tectorin is the most important noncollagenous component of the tectorial membrane and the otolith membrane in the maculae of the vestibular system. Defects in TECTA, the gene encodes alpha-tectorin, are cause of both dominant (DFNA8/12) and recessive (DFNB21) forms of deafness. Here, we report a three-generation Chinese family characterized by prelingual progressive sensorineural hearing impairment. We mapped the disease locus to chromosome 11q23-24 region, overlapping with the DFNA8/12 locus. Sequencing of candidate gene TECTA revealed a heterozygous c.5945C>A substitution in exon 19, causing amino acid substitution of Ala to Asp at a conservative position 1982. The A1982D substitution is consistent with hearing loss in this Chinese family and has not been found in 200 random control chromosomes. To our knowledge, this is the first TECTA mutation identified in Chinese population. Our data provides additional molecular and clinical information for establishing a better genotype–phenotype understanding of DFNA8/12.     

Development of a Real-Time Resistance Measurement for Vibrio parahaemolyticus Detection by the Lecithin-Dependent Hemolysin Gene

The marine bacterium Vibrio parahaemolyticus (V. parahaemolyticus) causes gastroenteritis in humans via the ingestion of raw or undercooked contaminated seafood, and early diagnosis and prompt treatment are important for the prevention of V. parahaemolyticus-related diseases. In this study, a real-time resistance measurement based on loop-mediated isothermal amplification (LAMP), electrochemical ion bonding (Crystal violet and Mg²⁺), real-time monitoring, and derivative analysis was developed. V. parahaemolyticus DNA was first amplified by LAMP, and the products (DNA and pyrophosphate) represented two types of negative ions that could combine with a positive dye (Crystal violet) and positive ions (Mg²⁺) to increase the resistance of the reaction liquid. This resistance was measured in real-time using a specially designed resistance electrode, thus permitting the quantitative detection of V. parahaemolyticus. The results were obtained in 1–2 hours, with a minimum bacterial density of 10 CFU.mL⁻¹ and high levels of accuracy (97%), sensitivity (96.08%), and specificity (97.96%) when compared to cultivation methods. Therefore, this simple and rapid method has a potential application in the detection of V. parahaemolyticus on a gene chip or in point-of-care testing.     

Fluorescence quenching method for the determination of carbazochrome sodium sulfonate with aromatic amino acids

In Britton‐Robinson (BR) buffer medium (pH 3.3), carbazochrome sodium sulfonate (CSS) can react with some aromatic amino acids such as tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) to form a 1:1 complex by electrostatic attraction, aromatic stacking interaction and Van der Waals' force, resulting in fluorescence quenching of these amino acids. Maximum quenching wavelengths were located at 352 nm (CSS‐Trp system), 303 nm (CSS‐Tyr system) and 284 nm (CSS‐Phe system), respectively. The fluorescence quenching value (ΔF) was proportional to the concentration of CSS in a certain range. The fluorescence quenching method for the determination of CSS showed high sensitivity, with detection limits of 31.3 ng/mL (CSS‐Trp system), 44.6 ng/mL (CSS‐Tyr system) and 315.0 ng/mL (CSS‐Phe system), respectively. The optimum conditions of the reaction conditions and the effect of coexisting substances were investigated and results showed that the method had good selectivity. The method was successfully applied for the rapid determination of CSS in blood and urine samples. Based on the bimolecular quenching constant K_q, the effect of temperature and Stern‐Volmer plots, this study showed that quenching of fluorescence of amino acids by CSS was a static quenching process. Copyright © 2012 John Wiley & Sons, Ltd.