Effects of ethanol and other alkanols on passive proton influx in the yeast Saccharomyces cerevisiae

Ethanol, isopropanol, propanol and butanol enhanced the passive influx of protons into deenergized cells of Saccharomyces cerevisiae. The influx followed first-order kinetics with a rate constant that increased exponentially with the alkanol concentration. The exponential enhancement constants increased with the lipid solubility of the alkanols, which indicated hydrophobic membrane regions as the target sites. While the enhancement constants were independent of pH over the range tested (3.3–5.0), the rate constants decreased linearly with increasing extracellular proton concentration, indicating the presence of an additional surface barrier against proton penetration, the effectiveness of which increased with protonation. The alkanols affected the acidification curves of energized yeast suspensions in such a way that the final pH values were linear functions of the alkanol concentrations. These results were consistent with a balance between active and passive proton movements at the final pH, the exponential enhancement constants calculated from the slopes being nearly identical with those obtained with deenergized cells. It was concluded that passive proton influx contributes to the kinetics of acidification in S. cerevisiae and that uncoupling contributes to the overall kinetics of alkanol-inhibited secondary active transport across the yeast plasma membrane.     

线粒体DNA4977bp大片缺失突变与喉癌的相关性研究

目的:探讨线粒体DNA4977bp大片缺失突变与喉癌的相关性。方法:选择2016年1月～2017年6月我院收治的喉乳头状瘤、喉癌患者,分别纳入良性肿瘤组、恶性肿瘤组,每组各150例。取两组患者的病变组织标本,分离癌及癌旁组织,提取总DNA,采用PCR扩增测序技术检测两组标本中线粒体DNA4977bp大片缺失突变情况。结果:基因测序结果显示恶性肿瘤组患者的线粒体DNA4977bp缺失突变率为39.33%,高于良性肿瘤组患者的1.33%,差异具有统计学意义(P0.05)。不同肿瘤分期患者的线粒体DNA4977bp缺失突变率比较,差异具有统计学意义(P0.05),且III期患者的突变率II期 I期 IV期;淋巴结转移患者的线粒体DNA4977bp缺失突变率高于淋巴结未转移患者差异具有统计学意义(P0.05)。结论:线粒体DNA4977bp大片缺失突变与喉癌的发生有关,可能促进的发生和进展。     

Complexities and pitfalls in analyzing and interpreting mitochondrial DNA content in human cancer

Mutations in the human mitochondrial genome have been observed in all types of human cancer, indicating that mutations might contribute to tumorigenesis, metastasis, recurrence, or drug response. This possibility is appealing because of the known shift from oxidative metabolism to glycolysis, known as the Warburg effect, that occurs in malignancy. Mitochondrial DNA (mtDNA) mutations could either be maternally inherited and predispose to cancer (germ line mutations) or occur sporadically in the mtDNA of specific tissues (tissue- or tumor-specific somatic mutations) and contribute to the tumor initiation and progression process. High-throughput sequencing technologies now enable comprehensive detection of mtDNA variation in tissues and bodily fluids, with the potential to be used as an early detection tool that may impact the treatment of cancer. Here, we discuss insights into the roles of mtDNA mutations in carcinogenesis, highlighting the complexities involved in the analysis and interpretation of mitochondrial genomic content, technical challenges in studying their contribution to pathogenesis, and the value of mtDNA mutations in developing early detection, diagnosis, prognosis, and therapeutic strategies for cancer.     

基于线粒体基因分析蓝孔雀与绿孔雀的遗传差异

种间的遗传差异是物种分类和确定保护管理单元的基础,本研究利用DNA条形码技术对未知样本进行鉴定,通过NCBI进行BLAST得到结果是:与绿孔雀的同源性为96%。近一步通过对蓝孔雀(Pavo cristatus)和绿孔雀(Pavo muticus)线粒体细胞色素C氧化酶Ⅰ(cytochrome coxidaseⅠ,COⅠ)基因及线粒体基因组的比较分析,结果表明两物种间的COⅠ基因在碱基组成、核苷酸多样性等各项指标上均具有明显差异。遗传距离分析结果表明蓝孔雀与绿孔雀种内遗传距离为分别0和0.012,种间遗传距离为0.045,表明种间仍具有明显的遗传差异。通过对两物种线粒体基因组各基因的比较分析,发现ND1基因变异位点所占比例相对较高,考虑作为绿孔雀和蓝孔雀种群遗传学研究的最优分子标记。本研究将为分析孔雀类群间的系统发育及制定绿孔雀的保护措施提供了更多科学依据。     

Anti-cancer activity of biosynthesized silver nanoparticles using Avicennia marina against A549 lung cancer cells through ROS/mitochondrial damages

The biosynthesized Ag NPs was synthesized by using marine mangrove plant extract Avicennia marina. The synthesized Ag NPs was confirmed by various physiochemical characterization including UV-spectrometer and XRD analysis. In addition, the shape and of the synthesized Ag NPs was morphologically identified by SEM initially and TEM finally. After confirmation, the anti-cancer property of synthesized Ag NPs was confirmed at 50 µg/mL concentration against A549 lung cancer cells by MTT assay. Further, the ability to stimulate the ROS generation and mitochondrial membrane at the IC₅₀ concentration of Ag NPs was confirmed by fluorescence microscopy using DCFH-DA and rhodamine 123 dyes respectively. Finally, the result was concluded that the synthesized Ag NPs has improved anti-cancer activity against A549 cells at lowest concentration.     

PGAM5: A crucial role in mitochondrial dynamics and programmed cell death

In response to mitochondrial damage, mitochondria activate mitochondrial dynamics to maintain normal functions, and an imbalance in mitochondrial dynamics triggers multiple programmed cell death processes. Recent studies have shown that phosphoglycerate mutase 5 (PGAM5) is associated with mitochondrial damage. PGAM5 activates mitochondrial biogenesis and mitophagy to promote a cellular compensatory response when mitochondria are mildly damaged, whereas severe damage to mitochondria leads to PGAM5 inducing excessive mitochondria fission, disruption to mitochondrial movement, and amplification of apoptosis, necroptosis and mitophagic death signals, which eventually evoke cell death. PGAM5 functions mainly through protein-protein interactions and specific Ser/Thr/His protein phosphatase activity. PGAM5 is also regulated by mitochondrial proteases. Detection of PGAM5 and its interacting protein partners should enable a more accurate evaluation of mitochondrial damage and a more precise method for the diagnosis and treatment of diseases.     

基于线粒体D-loop区和Cyt b基因分析广西禾花鲤三个群体遗传结构

研究基于线粒体D-loop区和Cyt b基因部分序列, 分析了广西全州、融水、环江三地禾花鲤(Cyprinus carpio)的遗传结构。在3个群体中共鉴定到19种D-loop与Cyt b序列的组合单倍型, 总的单倍型多样性(H_d)和核苷酸多样性(π)分别为0.916±0.010和0.008±0.004, 禾花鲤线粒体DNA具有单倍型多样性高和核苷酸多样性低的特点。环江群体单倍型多样性最低, 但是核苷酸多样性却最高, 反映了环江群体存在最明显的谱系混杂。分子方差分析(AMOVA)显示遗传变异主要来源于群体内部(71.54%), 禾花鲤三个群体间有显著的遗传分化(F_st=0.285; P<0.01)。系统发育分析表明, 多数样本的线粒体单倍型属于华南鲤(C. carpio rubrefusus)类型, 同时三地禾花鲤中均检测到一定频率的西鲤(C. carpio carpio)或远东鲤(C. carpio haematopterus)类型的线粒体单倍型, 提示禾花鲤可能受到鲤养殖品种的杂交渐渗。研究初步揭示了广西禾花鲤的种质资源现状, 为禾花鲤这一地方特色“稻鱼共作”品种的选育和苗种管理提供了必要的依据。     

A review of the genus Rusa in the indo-malayan archipelago and conservation efforts

Genus Rusa, belonging to the deer family Cervidae is native to the Indo-Malaya Archipelago (IMA). However, detailed information on the Rusa genus in the IMA is limited. This review provides comprehensive information on the Rusa genus in the IMA including, threats and conservation efforts. There are four species of deer in Rusa genus, which is Sambar deer (Rusa unicolor), Javan deer (Rusa timorensis), Visayan spotted deer (Rusa alfredi) and Philippine deer (Rusa marianna). Despite their wide distribution in the South Asian and Southeast Asian regions, they are under serious threats. Some conservation efforts that are being done to protect and conserve them among others are; (1) facilities protection, (2) habitat enrichment programme, (3) Ex-situ conservation, (4) legislations, and (5) captive breeding. Conservation through genetics is also an important step in conserving these species. Recommendations for conservation of the genus are also discussed; 1. maintenance of ecosystem. 2. more effective monitoring system on the existing protected area. 3. ex-situ conservation, and 4. habitat monitoring.     

Small and overlooked: Phylogeny of the genus Trigonodactylus (Squamata: Gekkonidae), with the first record of Trigonodactylus arabicus from Jordan

Geckos of the genus Trigonodactylus are widely distributed in the sand deserts of the Arabian Peninsula. Three species of this genus are currently recognized, with a fourth one, Stenodactylus pulcher, which placement within Trigonodactylus has been tentatively suggested, but not yet confirmed. We present a phylogenetic analysis of the genus Trigonodactylus with new specimens collected in central Saudi Arabia and southern Jordan. New genetic data has been generated from three mitochondrial markers to investigate the phylogenetic relationships of all species of the genus and to assess the putative generic assignment of S. pulcher. Our results confirm that S. pulcher indeed belongs within Trigonodactylus, branching as a sister lineage to all other species of the genus. The new samples cluster within Trigonodactylus arabicus, thus confirming the genetic homogeneity of the species across its large and seemingly inhospitable range. The new specimen collected in southern Jordan represents the first record for the country and a considerable range extension to the northwest from all previously reported localities. Our findings and discovery of a new species for Jordan highlight the need of more field surveys to be carried out in the underexplored parts of Jordan and northern Saudi Arabia, as these places still hold a potential for new discoveries and are crucial for understating the biogeography of the Arabian herpetofauna.