Slc7a11基因在不同被毛颜色哈萨克羊皮肤组织中的表达分析

Slc7a11基因属于溶质转运家族,编码胱氨酸/谷氨酸xCT转运载体,经证实该基因调控黑色素与伪黑色素的转换。文章利用实时荧光定量PCR技术分析Slc7a11基因在3种不同毛色哈萨克绵羊羔羊皮肤组织中的mRNA转录水平,构建原核表达载体,诱导表达融合蛋白,并对包涵体蛋白进行纯化,免疫新西兰大白兔制备抗血清,最后检测不同毛色皮肤中该蛋白的表达水平。结果表明,Slc7a11基因在3种毛色皮肤中的表达水平有显著差异,棕色被毛皮肤中表达水平最高,其次是黑色,在白色中表达最少。利用纯化的融合蛋白制备多克隆抗体,发现sxCT蛋白在棕色被毛中表达最高,其次是黑色,白色最低,因此,Slc7a11基因可能与哈萨克绵羊毛色表型有相关性。     

推进国家微生物资源平台建设,支撑微生物学科发展——“第七届全国微生物资源学术暨国际微生物系统与分类学研讨会”专刊序言

微生物资源是国家战略性生物资源之一,是支撑微生物学科发展与技术创新的重要基础。中国作为微生物资源的大国,近年来,通过"国家微生物资源平台"项目的建设,在微生物资源的分离、收集、保藏与共享等方面都取得了较大的发展。在我国微生物资源科技工作者的共同努力下,微生物新种的分离与发表也跃居世界首位。《微生物学通报》组织了本期"微生物资源"主题刊,旨在展示微生物资源学领域的最新进展,加强微生物资源学领域学术交流,提升我国微生物资源分类和系统学研究水平,促进微生物资源学科发展,推进国家微生物资源平台建设。     

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.     

Fullerol-fluorescein isothiocyanate phosphorescent labeling reagent for the determination of glucose and alkaline phosphatase

The active -OH group in fullerol (F-ol) could react with the dissociated -COOH group in fluorescein isothiocyanate (FITC) to form F-ol-(FITC)_n, which could emit room temperature phosphorescence (RTP) signal of F-ol and FITC on acetate cellulose membrane (ACM), respectively. Their RTP signals were enhanced by N,N-dimethylaniline (DMA). The labeling reaction between the -NCS group of FITC in DMA-F-ol-(FITC)_n and the -NH₂ group in wheat germ agglutinin (WGA) produced DMA-F-ol-(FITC)_n-WGA, which could further take affinity adsorption (AA) reaction with bioactive substances (BS), such as glucose and alkaline phosphatase (AP), to produce DMA-F-ol-(FITC)_n-WGA-BS. Both of these two products could maintain the good RTP characteristics of F-ol and FITC. Based on the facts above, a new phosphorescent labeling reagent, DMA-F-ol-FITC, was developed, and a new affinity adsorption solid substrate room temperature phosphorimetry (AASSRTP) for the determination of BS was established. This method was applied to the determination of BS in human serum and the diagnosis of diseases, with the results agreeing very well with those of enzyme-linked immunosorbent assay (ELISA). The mechanism of DMA-F-ol-(FITC)_n labeling of WGA and AASSRTP for the determination of BS is discussed.     

Plant pleiotropic drug resistance transporters:Transport mechanism,gene expression,and function

Pleiotropic drug resistance(PDR) transporters belonging to the ABCG subfamily of ATP-binding cassette(ABC)transporters are identified only in fungi and plants. Members of this family are expressed in plants in response to various biotic and abiotic stresses and transport a diverse array of molecules across membranes. Although their detailed transport mechanism is largely unknown, they play important roles in detoxification processes, preventing water loss, transport of phytohormones,and secondary metabolites. This review provides insights into transport mechanisms of plant PDR transporters, their expression profiles, and multitude functions in plants.     

河鲀毒素——一种具有缓解癌性疼痛潜力的药物

河鲀毒素（tetrodotoxin,TTX）是一种剧毒的生物碱类天然神经毒素，具有选择性阻断钠离子通道作用。人体摄入TTX后会产生致命影响，对人类的致死剂量范围1.5～2.0 mg （血药浓度9μg/L）。但以远低于其半数致死量（LD50）给患者施用TTX时，却可以治疗多种疾病，包括海洛因和可卡因戒断症状、脊髓损伤、脑外伤、肿瘤、神经性疼痛和内脏疼痛等。研究人员经过几十年不懈地探索，在TTX应用于生物医学领域，尤其是治疗癌症相关疼痛方面取得可喜进展，本文着重介绍TTX作为缓解癌性疼痛药物的临床开发、作用的有效性和安全性等最新结果，展示TTX缓解癌性疼痛的前景。     

Time to update the sectional classification of Ilex (Aquifoliaceae): New insights from Ilex phylogeny,morphology, and distribution

Resolving the infrageneric classification of species-rich genera has been challenging in plant taxonomy. Ilex L. is a subcosmopolitan genus with over 600 species of dioecious trees and shrubs. Many classification systems based on morphological data have been proposed during the past 250 years. However, these systems (such as Loesener's and Galle's systems) may not truly reflect Ilex's evolutionary trajectories because most of those system's infrageneric hierarchies are not monophyletic. In this study, we reconstructed a phylogeny of Ilex L. comprising 15 moderately to highly supported clades using rigorously identified samples (202 species) and closely authenticated gene sequences of three nuclear genes [internal transcribed spacer (ITS), external transcribed spacer (ETS), and nepGS]. The newly generated phylogenetic tree resembles essentially that of the nuclear tree of Manen et al., but shows conspicuous topological differences with the phylogeny of Yao et al. Closely scrutinizing morphological variation and distributional patterns of 202 species, this study found that most lineages of Ilex identified herein are well defined by a particular trait or a combination of morphological and distributional traits, displaying phylogeny–morphology–distribution conformity that has seldom been uncovered in previous studies. Given the general phylogeny–morphology–distribution conformity revealed in this genus, we put forward an updated sectional classification system for Ilex that temporarily contains 14 sections. The new classification will provide a robust framework for studying the evolution and diversification of this ecologically and economically important genus.