Physical mapping of an adult plant stripe rust resistance gene from Triticum monococcum

Stripe rust (Puccinia striiformis f. sp. tritici) is one of the major devastating disease which causes large reduction in wheat yield. T. monococcum is an attractive diploid species for gene discovery in wheat with smaller genome size of 5700 Mb compared to 17,300 Mb of bread wheat. An adult plant stripe rust resistance QTL QYrtm.pau-2A was mapped on chromosome 2A flanked by two SSR markers Xwmc170 and Xwmc407. In the present study, two gene based markers Pau_Ta2AL_Gene45 and Pau_Ta2AL_Gene54 developed from 2A specific ESTs were found to map close to QYrtmpau-2A to narrow down the region for candidate gene identification. Utilizing sequence information of these two markers, four BAC clones were identified from the Minimum Tiling Path of 2AL assembly and were sequenced. SSR markers were designed from these BAC sequences and mapped to chromosome 2A. A 50 Mb region of wheat chromomse 2A was identified to harbor stripe rust resistance gene of T. monococcum. Gene based markers identified in the present investigation can be used for marker assisted introgression of QYrtm.pau-2A from T. monococcum to cultivated wheat.     

IPBES框架下的生物多样性和生态系统服务区域评估及政策经验

生物多样性和生态系统服务为人类的生计和良好的生活质量奠定了重要基础。然而, 越来越多的研究表明, 生物多样性和生态系统服务在全球范围内的持续下降使自然对人类的贡献大幅降低。多尺度评估能够说明不同尺度下生物多样性的现状, 有利于制定适合区域特点、符合国情的决策建议。2013年12月, 生物多样性和生态系统服务政府间科学政策平台(Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, IPBES)通过第一轮工作方案, 决定开展“区域/次区域生物多样性和生态系统服务评估”(简称“区域评估”), 即评估亚洲-太平洋(简称亚太)、美洲、非洲以及欧洲-中亚四大地理区域的生物多样性和生态系统服务。区域评估报告及其决策者摘要已在IPBES第六次全体会议上(2018年3月, 哥伦比亚麦德林)审议通过。本文概述了四大地理区域的生物多样性的重要性、生物多样性保护领域取得的进展、面临的主要危机和机遇, 探讨了评估对其他国际进程的影响, 综合分析了各区域生物多样性和生态系统服务的特点以及各区域评估结果的差别, 总结了评估的政策经验, 以期为中国的生物多样性保护提供科学参考。     

Dissecting the in vivo assembly of the 30S ribosomal subunit reveals the role of RimM and general features of the assembly process

Ribosome biogenesis is a tightly regulated, multi-stepped process. The assembly of ribosomal subunits is a central step of the complex biogenesis process, involving nearly 30 protein factors in vivo in bacteria. Although the assembly process has been extensively studied in vitro for over 40 years, very limited information is known for the in vivo process and specific roles of assembly factors. Such an example is ribosome maturation factor M (RimM), a factor involved in the late-stage assembly of the 30S subunit. Here, we combined quantitative mass spectrometry and cryo-electron microscopy to characterize the in vivo 30S assembly intermediates isolated from mutant Escherichia coli strains with genes for assembly factors deleted. Our compositional and structural data show that the assembly of the 3′-domain of the 30S subunit is severely delayed in these intermediates, featured with highly underrepresented 3′-domain proteins and large conformational difference compared with the mature 30S subunit. Further analysis indicates that RimM functions not only to promote the assembly of a few 3′-domain proteins but also to stabilize the rRNA tertiary structure. More importantly, this study reveals intriguing similarities and dissimilarities between the in vitro and the in vivo assembly pathways, suggesting that they are in general similar but with subtle differences.     

Serum level of brain-derived neurotrophic factor in fibromyalgia syndrome correlates with depression but not anxiety

Brain-derived neurotrophic factor (BDNF) has been known to play a role in fibromyalgia syndrome (FMS) patients. Depression and anxiety are quite common additional symptoms in FMS. However the role of BDNF in these symptoms still needs to be elucidated. Although BDNF has been shown to be relevant in major depression, however studies could not show such differences between FMS patients with and without major depression. As mood-related symptom occurs frequently and differs in its intensity in FMS patients, BDNF level should be measured in subgroup regarding depression and anxiety scale. Therefore the aim of this study was to evaluate the correlation of BDNF in serum of FMS with intensity of depression and anxiety. Additionally, interleukin (IL)-6 was measured.     

High serum free fatty acids and low leptin levels: Plausible metabolic indicators of negative energy balance in early lactating Murrah buffaloes

Lactation is a highly demanding event in mammals, including buffaloes. It modulates the partitioning of nutrients, energy utilization, and food intake of the mother to meet her own and infant's energy needs. Failure to satisfy these energy needs leads to Negative Energy Balance (NEB). Currently, the only available indirect NEB indicator is Body Condition Score (BCS). However, direct dependency of the BCS on the peak depletion of body fat causes its inefficient use in a dairy farm. Thus, to establish objective NEB indicators in buffaloes, the serum levels of biochemical (serum β-hydroxybutyrate [BHBA] and free fatty acids [FFAs]), and endocrine (Growth Hormone [GH], insulin-like growth factor1 [IGF1], Insulin, and leptin) parameters were estimated in buffaloes. Our results revealed that serum FFA levels were significantly (p < 0.05) higher in high milk yielders (HMY) than low milk yielders (LMY) and heifers (H) during the 3rd and the 4th weeks of postpartum. The serum FFA levels were also significantly (p < 0.001) higher in the postpartum buffaloes with BCS < 3 in the field conditions. Further, serum leptin levels were significantly (p < 0.05) lower in HMY than LMY during the 3rd week of postpartum. However, the BHBA, GH, IGF1, and insulin levels were not significantly different between lactating buffaloes and H. These observations indicated that the NEB condition is probably restricted to the first month of early lactation in buffaloes. In conclusion, the simultaneous higher FFA and lower leptin levels could act as direct plausible metabolic indicators of NEB in buffaloes.     

Synthesis and inotropic activity of hydroindene derivatives

A synthetic approach to hydroindenic inotropic agents has been developed, starting from enantiopure Hajos-Parrish (1). Hajos-Wiechert (2), and related diketones. Their transformation into C-1 formyl derivatives and other subsequent synthetic targets is described. The results of the thermodynamic equilibration between both epimers of each formyl derivative are analysed. The inotropic activities of selected compounds on right and left atrial preparations are also evaluated and discussed.     

The C-terminal moiety of HIV-1 Vpr induces cell death via a caspase-independent mitochondrial pathway

Previous biochemical studies suggested that HIV-1-encoded Vpr may kill cells through an effect on the adenine nucleotide translocase (ANT), thereby causing mitochondrial membrane permeabilization (MMP). Here, we show that Vpr fails to activate caspases in conditions in which it induces cell killing. The knock-out of essential caspase-activators (Apaf-1 or caspase-9) or the knock-out of a mitochondrial caspase-independent death effector (AIF) does not abolish Vpr-mediated killing. In contrast, the cytotoxic effects of Vpr are reduced by transfection-enforced overexpression of two MMP-inhibitors, namely the endogenous protein Bcl-2 or the cytomegalovirus-encoded ANT-targeted protein vMIA. Vpr, which can elicit MMP through a direct effect on mitochondria, and HIV-1-Env, which causes MMP through an indirect pathway, exhibit additive (but not synergic) cytotoxic effects. In conclusion, it appears that Vpr induces apoptosis through a caspase-independent mitochondrial pathway.     

Mitochondrial permeability transition as a novel principle of hepatorenal toxicity in vivo

Atractyloside (Atr) binds to the adenine nucleotide translocator (ANT) and inhibits ANT-mediated ATP/ADP exchange on the inner mitochondrial membrane. In addition, Atr can trigger opening of a non-specific ion channel, within the ANT-containing permeability transition pore complex (PTPC), which is subject to redox regulation and inhibited by cyclosporin A (CsA). Here we show that the cytotoxic effects of Atr, both in vivo and in vitro, are determined by its capacity to induce PTPC opening and consequent mitochondrial membrane permeabilization (MMP). Thus, the Atr-induced MMP and death of cultured liver cells are both inhibited by CsA as well as by glutathione (GSH) and enhanced by GSH depletion. Similarly, the hepatorenal toxicity of Atr, assessed in vivo, was reduced by treating mice with CsA or a diet rich in sulfur amino acids, a regime which enhances mitochondrial GSH levels. Atr injection induced MMP in hepatocytes and proximal renal tubular cells, and MMP was reduced by either CsA or GSH. Acetaminophen (paracetamol)-induced acute poisoning was also attenuated by CsA and GSH, both in vitro and in vivo. Altogether these data indicate that PTPC-mediated MMP may determine the hepatorenal toxicity of xenobiotics in vivo.     

Cytofluorometric quantitation of apoptosis-driven inner mitochondrial membrane permeabilization

The mitochondrial matrix can be specifically labeled by loading cells with calcein and simultaneous quenching of the non-mitochondrial calcein fluorescence with cobalt (Co²⁺). Positive staining of mitochondria thus requires that the inner mitochondrial membrane functions as a barrier separating calcein (within the matrix) from Co²⁺ (outside of the matrix). Upon induction of apoptosis, such calcein/Co²⁺-labeled cells, demonstrate a decrease in the overall calcein fluorescence resulting from inner mitochondrial membrane permeabilization. This decrease can be quantified by cytofluorometry and can be dissociated from other apoptosis-associated mitochondrial perturbations such as the loss of the mitochondrial transmembrane potential ( _m ), the local overproduction of reactive oxygen species, and the mitochondrial release of cytochrome c. In some paradigms of apoptosis the loss of calcein/Co²⁺ (CC) staining can be dissociated from the _m loss, both of which may occur in a caspase-dependent or caspase-independent fashion, depending on the apoptosis inducer. Importantly, inner membrane permeabilization to CC may occur without a permanent _m dissipation in apoptosis, suggesting that transient permeabilization events could participate at the apoptotic cascade. Altogether, our data demonstrate that inner mitochondrial membrane permeabilization constitutes an early event in the apoptotic cascade.     

New method to assess mitophagy flux by flow cytometry

Mitochondrial autophagy, also known as mitophagy, is an autophagosome-based mitochondrial degradation process that eliminates unwanted or damaged mitochondria after cell stress. Most studies dealing with mitophagy rely on the analysis by fluorescence microscopy of mitochondrial-autophagosome colocalization. However, given the fundamental role of mitophagy in the physiology and pathology of organisms, there is an urgent need for novel quantitative methods with which to study this process. Here, we describe a flow cytometry-based approach to determine mitophagy by using MitoTracker Deep Red, a widely used mitochondria-selective probe. Used in combination with selective inhibitors it may allow for the determination of mitophagy flux. Here, we test the validity of the use of this method in cell lines and in primary cell and tissue cultures.