真菌色素与真菌感染

目的观察真菌色素与各种真菌感染的病理学和临床诊治的关系,进一步发展真菌色素相关的临床理论和实用技术。方法以近年来相关的研究和系列文献为基础,从真菌色素的理化性质、生物学特性、生物合成代谢、分子生物学、病理学特征和其对耐药性形成的影响等方面来阐述真菌色素所担负的重要病理生理学作用。结果真菌色素与其相应真菌菌株的生理代谢和致病性密切相关,是真菌细胞形态的固有结构,有极强的抵御外来离子辐射、极度温度变化、pH值改变和抗真菌药物作用的混合功能。结论致病性真菌色素是各种真菌感染的一个重要病原性毒力因素,也是引发耐药性形成的真菌固有的功能形态因素之一。     

大型真菌重金属污染生态学研究进展与展望

大型真菌是生物圈中重要的组成部分和生态资源,在自然界物质循环和维持生态平衡中发挥着非常重要的作用.本文从环境重金属污染对大型真菌的生态毒性效应、大型真菌对重金属的生物富集作用、大型真菌对重金属污染的生态适应机制、大型真菌对重金属污染的指示和生态修复作用等方面,较为全面地总结、评述了大型真菌重金属污染生态学的研究进展.随着重金属污染的加剧,加强研究大型真菌重金属污染生态学,对于大型真菌资源的合理利用和污染环境的生态修复具有重要的现实意义.     

大型真菌对重金属的生物富集作用及生态修复

大型真菌是一类重要的环境生物资源,对人类的生存具有重要作用.与绿色植物相比,大型真菌能够积累高浓度的Pb、Cd和Hg等重金属.本文论述了大型真菌对重金属的生物富集作用以及利用大型真菌进行重金属生态修复的优势,指出大型真菌种类、生态类型、富集重金属的生物学特性及其遗传潜能、大型真菌菌丝体和子实体的形态、部位、寿命以及结实间隔和环境因子等是影响大型真菌吸收和积累重金属的主要因素.筛选富集重金属功能强大、易于人工栽培、环境适应性强、便于后处理的大型真菌是今后研究的重要方向.     

中国7所高校校园大型真菌多样性研究进展

大型真菌是校园生态环境中重要的生物组分,优美的校园生态环境通常孕育着较高的生物多样性。对我国7所高校校园大型真菌资源多样性研究进行了综述,校订了已报道文献中校园大型真菌的物种名录,对校园大型真菌资源的研究、保育、利用与科普等方面提出了展望,以期为校园大型真菌的生态管理提供科学依据。     

大型真菌分子遗传连锁图谱研究进展

<正>大型真菌(macrofungi)中包括一些重要的食用真菌和药用真菌,在人类的经济生活中占有十分重要的地位(Chang Miles1989)。真菌学研究是生物学研究中的一个重要分支,但对大型真菌遗传     

大型真菌子实体发生的形态学过程及调控机制

大型真菌中很多种类具有较高的营养价值和药用价值,而食药用部位多为大型真菌的子实体,所以子实体的形成对大型真菌的开发应用就显得尤为重要。在大型真菌生活史中,子实体的发生揭示着真菌完成了从营养生长向生殖生长的转变。从理论上来说,菌丝体只需完成营养生长,即可进入生殖生长;而实际上,子实体的发生受到各种环境因素、遗传因素等的影响。因此,本文从子实体发生的形态学过程、环境影响因素、分子调控机制等方面综述了近年国内外关于大型真菌子实体发生的研究概况,为大型真菌的系统研究和重要食药用菌的栽培驯化提供理论借鉴和参考依据。     

中国森林大型真菌重要类群多样性和系统学研究

大型真菌主要为担子菌门的真菌和少数为子囊菌门的真菌,该类真菌具有重要的经济价值和生态功能,主要生长在森林生态系统中.30年来作者对我国几乎所有类型森林生态中的大型真菌进行了系统调查和采集,共采集标本11.2万号.基于对这些材料的形态学及分子系统学研究,并结合生态学和生物地理学特征,共鉴定出中国森林大型真菌4 250种,...     

大型真菌萜类化合物活性研究进展

大型真菌是天然生物活性物质的重要来源,具有潜在的药用价值。萜类化合物作为一类重要的生物活性物质,来源分布广泛,是天然产物中最大的家族。许多来自于大型真菌中的萜类化合物已被验证其药理活性,本文对近年来大型真菌萜类化合物的抗肿瘤、抗菌、抗炎、抗氧化活性及其商业应用进行了概述。     

中国大型真菌红色名录评估研究进展

大型真菌具有重要的生态价值和经济价值, 但由于环境污染、气候变化、生境丧失与破碎化, 以及资源过度利用等因素, 其生物多样性受到严重威胁。为了全面评估中国大型真菌的生存状况, 国家生态环境部(原环境保护部)联合中国科学院于2016年启动了《中国生物多样性红色名录——大型真菌卷》的编制工作。经广泛和全面收集文献资料, 依据IUCN物种红色名录等级与标准, 结合大型真菌特点和国内研究现状, 制定了中国大型真菌红色名录评估方法和流程, 动员和组织了全国相关研究力量, 对9,302种大型真菌的受威胁状况进行了评估。结果显示, 中国大型真菌受威胁物种(包括疑似灭绝、极危、濒危、易危)共97个, 占被评估物种总数的1.04%; 近危101种, 占总数的1.09%; 无危2,764种, 占总数的29.71%; 数据不足6,340种, 占总数的68.16%。此次评估工作汇集了全国140多位专家的智慧, 是国内外迄今为止涉及物种数量最大、类群范围最宽、覆盖地域最广、参与人员最多的一次大型真菌生存状况评估, 对我国大型真菌多样性保护与管理具有重要意义。     

抚育间伐对油松人工林下大型真菌的影响

真菌在森林凋落物分解过程中起重要作用,研究间伐如何影响真菌进而影响凋落物分解,对深入了解间伐调控人工林凋落物分解有重要意义。本文以抚育间伐后的中龄油松人工林为研究对象,设立对照（I）、轻度（II）、中度（III）和强度（IV）4种间伐强度,于2011年对间伐后林下大型真菌进行两次调查,分析了不同间伐强度下大型真菌的科的分布、优势种组成和生态指标（包括丰富度指数、多样性指数和均匀度指数）。结果表明：（1）8月、9月采集到的大型真菌分别为35种和25种,分属13个科和10个科;（2）在大型真菌出菇期,间伐改变了大型真菌的优势种组成,对照林下大型真菌优势种最初为外生菌根菌（粘盖乳牛肝菌 血红铆钉菇）后变为腐生菌（大盖小皮伞和脐顶小皮伞）,而间伐后林下优势种始终为腐生菌;（3）间伐影响大型真菌的生态指标,中度间伐林下大型真菌丰富度和多样性指数最高。总之,适度间伐不仅有利于提高林下大型真菌的丰富度与多样性,同时使其群落结构发生改变,群落优势种由外生菌根菌变为以分解凋落物为主的腐生菌,可促进凋落物的分解和养分循环。     

FRACTIONATION OF THE EYE PIGMENTS OF DROSOPHILA MELANOGASTER

Eye pigments of normal and mutant types of D. melanogaster have been extracted with water and fractionated by chromatographic adsorption on powdered talc. Spectra of all the fractions obtainable in solution have been measured and the general chemical behavior of the pigments is described. Two chemically distinct groups of pigments are found, to be identified with the earlier designated red and brown components. The red component in the wild-type eye contains three well defined pigments, two of them capable of further subdivision so that the total number of fractions obtained is five. There is also present a brown component pigment which could not be treated quantitatively by the methods employed. All members of the wild-type red component are found in cinnabar eyes, unaccompanied by the brown component. Conversely, brown eyes contain a pigment indistinguishable from the wild-type brown component, virtually alone. In sepia eyes, one red component and two brown component pigments can be distinguished, all three pigments differing from those of wild-type eyes. Pigments apparently identical with those found in wild-type melanogaster eyes have also been found in D. virilis.     

THE DISTRIBUTION OF STRUCTURAL COLOURS AND UNUSUAL PIGMENTS IN THE CLASS AVES.

Structural colours in birds are surveyed systematically. From this survey, the common structural configurations in feathers, producing bright colours of the iridescent and non-iridescent types respectively, are seen to exclude one another
Feather pigments of unusual shades or chemical constitutions have been included in the survey, since some of them produce colour effects similar to structural colours of the non-iridescent type     

Trichromacy in Australian marsupials

Vertebrate color vision is best developed in fish, reptiles, and birds with four distinct cone receptor visual pigments. These pigments, providing sensitivity from ultraviolet to infrared light, are thought to have been present in ancestral vertebrates. When placental mammals adopted nocturnality, they lost two visual pigments, reducing them to dichromacy; primates subsequently reevolved trichromacy. Studies of mammalian color vision have largely overlooked marsupials despite the wide variety of species and ecological niches and, most importantly, their retention of reptilian retinal features such as oil droplets and double cones. Using microspectrophotometry (MSP), we have investigated the spectral sensitivity of the photoreceptors of two Australian marsupials, the crepuscular, nectivorous honey possum (Tarsipes rostratus) and the arhythmic, insectivorous fat-tailed dunnart (Sminthopsis crassicaudata); these species are representatives of the two major taxonomic divisions of marsupials, the diprotodonts and polyprotodonts, respectively. Here, we report the presence of three spectrally distinct cone photoreceptor types in both species. It is the first evidence for the basis of trichromatic color vision in mammals other than primates. We suggest that Australian marsupials have retained an ancestral visual pigment that has been lost from placental mammals.     

Diversity in plant red pigments: anthocyanins and betacyanins

Plant pigments are of interest for research into questions of basic biology as well as for purposes of applied biology. Red colors in flowers are mainly produced by two types of pigments: anthocyanins and betacyanins. Though anthocyanins are broadly distributed among plants, betacyanins have replaced anthocyanins in the Caryophyllales. Red plant pigments are good indicator metabolites for evolutionary studies of plant diversity as well as for metabolic studies of plant cell growth and differentiation. In this review, we focus on the biosynthesis of anthocyanins and betacyanins and the possible mechanisms underlying the mutual exclusion of betalains and anthocyanins based on the regulation of the biosynthesis of these red pigments.     

Carotenoid pigments and the selectivity of psittacofulvin-based coloration systems in parrots

Carotenoid pigments are commonly used as colorants of feathers and bare parts by birds. However, parrots (Aves: Psittaciformes) use a novel class of plumage pigments (called psittacofulvins) that, like carotenoids, are lipid-soluble and red, orange, or yellow in color. To begin to understand how and why parrots use these pigments and not carotenoids in their feathers, we must first describe the distribution of these two types of pigments in the diet, tissues, and fluids of these birds. Here, we studied the carotenoid content of blood in five species of parrots with red in their plumage to see if they show the physiological ability to accumulate carotenoids in the body. Although Scarlet (Ara macao) and Greenwing Macaws (Ara chloroptera) and Eclectus (Eclectus roratus), African Gray (Psittacus erithacus) and Blue-fronted Amazon (Amazona aestiva) Parrots all use psittacofulvins to color their feathers red, we found that they also circulated high concentrations of both dietary (lutein, zeaxanthin, beta-cryptoxanthin) and metabolically derived (anhydrolutein, dehydrolutein) carotenoids through blood at the time of feather growth, at levels comparable to those found in many other carotenoid-colored birds. These results suggest that parrots have the potential to use carotenoids for plumage pigmentation, but preferentially avoid depositing them in feathers, which is likely under the control of the maturing feather follicle. As there is no evidence of psittacofulvins in parrot blood at the tune of feather growth, we presume that these pigments are locally synthesized by growing feathers within the follicular tissue.     

Raman Spectroscopy of Microbial Pigments

Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions.     

Season-, sex-, and age-specific accumulation of plasma carotenoid pigments in free-ranging white-winged crossbills Loxia leucoptera

Many birds acquire carotenoid pigments from foods and deposit these pigments into feathers and bare‐parts to become sexually attractive, but little work has been done on the interindividual and temporal variability in the types and amounts of carotenoids that free‐ranging individuals have available for use in coloration or other functions (e.g., in immunomodulation). To address this issue, we studied intra‐annual variation in plasma carotenoid profiles of juvenile and adult white‐winged crossbills Loxia leucoptera of both sexes. Adult male crossbills exhibit bright red carotenoid‐based plumage pigmentation, whereas females uniformly display drab yellow feather coloration and juvenile males only occasionally display some orange or pink color. Yellow xanthophylls (e.g., lutein, zeaxanthin) were predominant in plasma of birds from both sexes and age classes throughout the year. Plasma xanthophylls levels tended to be highest in the summer, when crossbills increase seed consumption for breeding as well as supplement their diet with insects. Blood accumulation of three other, less common plasma carotenoids‐β‐cryptoxanthin, rubixanthin, and gazaniaxanthin‐varied in a highly season‐, sex‐, and age‐dependent fashion. These carotenoids were virtually absent in juvenile or adult female plasma at all times of year and were only present in male plasma, at higher concentrations in adults than juveniles, during the period of feather growth (Sept.–Nov.). These pigments have been reported as valuable precursors of the metabolically derived red pigments (e.g., 3‐hydroxy‐echinenone, 4‐oxo‐rubixanthin, and 4‐oxo‐gazaniaxanthin, respectively) that appear in the plumage of male crossbills. These findings suggest that male crossbills either adopt a season‐specific foraging strategy to acquire foods rich in these pigments at the time they are needed to develop red coloration, or have a unique physiological ability to metabolically produce these pigments or absorb them from food during molt, in order to maximize color production.     

Antioxidant capacity of novel pigments from an Antarctic bacterium

In Antarctica microorganisms are exposed to several conditions that trigger the generation of reactive oxygen species, such as high UV radiation. Under these conditions they must have an important antioxidant defense system in order to prevent oxidative damage. One of these defenses are pigments which are part of the non-enzymatic antioxidant mechanisms. In this work we focused on the antioxidant capacity of pigments from an Antarctic microorganism belonging to Pedobacter genus. This microorganism produces different types of pigments which belong to the carotenoids group. The antioxidant capacity of a mix of pigments was analyzed by three different methods: 1,1-diphenyl-2-picrylhydrazyl, ROS detection and oxygen electrode. The results obtained from these approaches indicate that the mix of pigments has a strong antioxidant capacity. The oxidative damage induced by UVB exposure to liposomes was also analyzed. Intercalated pigments within the liposomes improved its resistance to lipid peroxidation. Based on the analysis carried out along this research we conclude that the antioxidant properties of the mix of pigments protect this bacterium against oxidative damage. These properties make this mix of pigments a powerful antioxidant mixture with potential biotechnological applications.     

A high-throughput analysis method to detect regions of interest and quantify zebrafish embryo images

Zebrafish is widely used to understand neural development and model various neurodegenerative diseases. Zebrafish embryos are optically transparent, have a short development period, and can be kept alive in microplates for days, making them amenable to high-throughput microscopic imaging. As a result of high-throughput experiments, a large number of images can be generated in a single experiment, posing a challenge to researchers to analyze them efficiently and quantitatively. In this work, we develop an image processing focused on detecting and quantifying pigments in zebrafish embryos. The algorithm automatically detects a region of interest (ROI) enclosing an area around the pigments and then segment the pigments for quantification. In this process, the algorithm identifies the head and torso at first, and then finds the boundaries corresponding to the back and abdomen by taking advantage of a priori information about the anatomy of zebrafish embryos. The method is robust in terms that it can detect and quantify pigments even when the embryos have different orientations and curvatures. We used real data to demonstrate the performance of the method to extract phenotypic information from zebrafish embryo images and compared its results with manual analysis for verification.     

Formation of water-solubleMonascus red pigments by biological and semi-synthetic processes

Summary New water-soluble red pigments were produced byMonascus sp. in a chemically defined fermentation medium containing glutamate as nitrogen source. They were isolated and characterized as glutamate derivatives of the well-known orangeMonascus pigments (monascorubrin and rubropunctatin). The new pigments have several advantages over the known redMonascus pigments (rubropunctamine and monascorubramine) including very high water-solubility, higher absorption coefficient, and greater resistance to decoloration by light. Adding glutamate, glycine or leucine to a resting-cell system led to the formation of specific water-soluble red pigments corresponding to the exogenous amino acid. The water-soluble red pigments produced by resting-cells have retention times identical to those of the corresponding red derivatives made chemically from the orange pigments in methanol-phosphate buffer at pH 7. The hydrophobicities of the amino acid sources correspond to the HPLC retention times of the red pigments derived from them.