共查询到20条相似文献,搜索用时 31 毫秒
1.
Background
The Streptophyta comprise all land plants and six monophyletic groups of charophycean green algae. Phylogenetic analyses of four genes from three cellular compartments support the following branching order for these algal lineages: Mesostigmatales, Chlorokybales, Klebsormidiales, Zygnematales, Coleochaetales and Charales, with the last lineage being sister to land plants. Comparative analyses of the Mesostigma viride (Mesostigmatales) and land plant chloroplast genome sequences revealed that this genome experienced many gene losses, intron insertions and gene rearrangements during the evolution of charophyceans. On the other hand, the chloroplast genome of Chaetosphaeridium globosum (Coleochaetales) is highly similar to its land plant counterparts in terms of gene content, intron composition and gene order, indicating that most of the features characteristic of land plant chloroplast DNA (cpDNA) were acquired from charophycean green algae. To gain further insight into when the highly conservative pattern displayed by land plant cpDNAs originated in the Streptophyta, we have determined the cpDNA sequences of the distantly related zygnematalean algae Staurastrum punctulatum and Zygnema circumcarinatum. 相似文献2.
A metabarcoding comparison of windward and leeward airborne algal diversity across the Ko‘olau mountain range on the island of O'ahu,Hawai‘i1
下载免费PDF全文
![点击此处可从《Journal of phycology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alison R. Sherwood Monica N. Dittbern Emily T. Johnston Kimberly Y. Conklin 《Journal of phycology》2017,53(2):437-445
Airborne algae from sites on the windward (n = 3) and leeward (n = 3) sides of the Ko‘olau Mountain range of O‘ahu, Hawai‘i, were sampled for a 16 d period during January and February 2015 using passive collection devices and were characterized using Illumina MiSeq sequencing of the universal plastid amplicon marker. Amplicons were assigned to 3,023 operational taxonomic units (OTUs), which included 1,189 cyanobacteria, 1,009 heterotrophic bacteria, and 304 Eukaryota (of which 284 were algae and land plants). Analyses demonstrated substantially more OTUs at windward than leeward O‘ahu sites during the sampling period. Removal of nonalgal OTUs revealed a greater number of algal reads recovered from windward (839,853) than leeward sites (355,387), with the majority of these being cyanobacteria. The 1,234 total algal OTUs included cyanobacteria, diatoms, cryptophytes, brown algae, chlorophyte green algae, and charophyte green algae. A total of 208 algal OTUs were identified from leeward side samplers (including OTUs in common among samplers) and 1,995 algal OTUs were identified from windward samplers. Barcoding analyses of the most abundant algal OTUs indicated that very few were shared between the windward and leeward sides of the Ko‘olau Mountains, highlighting the localized scale at which these airborne algae communities differ. Back trajectories of air masses arriving on O‘ahu during the sampling period were calculated using the NOAA HY‐SPLIT model and suggested that the sampling period was composed of three large‐scale meteorological events, indicating a diversity of potential sources of airborne algae outside of the Hawaiian Islands. 相似文献
3.
4.
5.
Xiujun Xie Guangce Wang Guanghua Pan Shan Gao Pu Xu Jianyi Zhu 《BMC developmental biology》2010,10(1):43
Background
Red algae are primitive photosynthetic eukaryotes, whose spores are ideal subjects for studies of photosynthesis and development. Although the development of red alga spores has received considerable research attention, few studies have focused on the detailed morphological and photosynthetic changes that occur during the early development of tetraspores of Gracilaria vermiculophylla (Ohmi) Papenfuss (Gracilariales, Rhodophyta). Herein, we documented these changes in this species of red algae. 相似文献6.
7.
Estelle Deniaud-Bou?t Nelly Kervarec Gurvan Michel Thierry Tonon Bernard Kloareg Cécile Hervé 《Annals of botany》2014,114(6):1203-1216
Background and Aims
Brown algae are photosynthetic multicellular marine organisms evolutionarily distant from land plants, with a distinctive cell wall. They feature carbohydrates shared with plants (cellulose), animals (fucose-containing sulfated polysaccharides, FCSPs) or bacteria (alginates). How these components are organized into a three-dimensional extracellular matrix (ECM) still remains unclear. Recent molecular analysis of the corresponding biosynthetic routes points toward a complex evolutionary history that shaped the ECM structure in brown algae.Methods
Exhaustive sequential extractions and composition analyses of cell wall material from various brown algae of the order Fucales were performed. Dedicated enzymatic degradations were used to release and identify cell wall partners. This approach was complemented by systematic chromatographic analysis to study polymer interlinks further. An additional structural assessment of the sulfated fucan extracted from Himanthalia elongata was made.Key Results
The data indicate that FCSPs are tightly associated with proteins and cellulose within the walls. Alginates are associated with most phenolic compounds. The sulfated fucans from H. elongata were shown to have a regular α-(1→3) backbone structure, while an alternating α-(1→3), (1→4) structure has been described in some brown algae from the order Fucales.Conclusions
The data provide a global snapshot of the cell wall architecture in brown algae, and contribute to the understanding of the structure–function relationships of the main cell wall components. Enzymatic cross-linking of alginates by phenols may regulate the strengthening of the wall, and sulfated polysaccharides may play a key role in the adaptation to osmotic stress. The emergence and evolution of ECM components is further discussed in relation to the evolution of multicellularity in brown algae. 相似文献8.
Elaine M Forbes Siân R Nieduszynska Fiona K Brunton Joanne Gibson L Anne Glover Ian Stansfield 《BMC molecular biology》2007,8(1):94
Background
In the C. albicans retrotransposon Tca2, the gag and pol ORFs are separated by a UGA stop codon, 3' of which is a potential RNA pseudoknot. It is unclear how the Tca2 gag UGA codon is bypassed to allow pol expression. However, in other retroelements, translational readthrough of the gag stop codon can be directed by its flanking sequence, including a 3' pseudoknot. 相似文献9.
10.
Hana Bandouchova Miroslav Pohanka Kristina Vlckova Veronika Damkova Lucie Peckova Jana Sedlackova Frantisek Treml Frantisek Vitula Jiri Pikula 《Acta veterinaria Scandinavica》2011,53(1):2
Background
The aim of the present study was to investigate biochemical and oxidative stress responses to experimental F. tularensis infection in European brown hares, an important source of human tularemia infections. 相似文献11.
Jiu-Cun Wang Syeling Lai Xinjian Guo Xuefeng Zhang Benoit de Crombrugghe Sonali Sonnylal Frank C Arnett Xiaodong Zhou 《Arthritis research & therapy》2010,12(2):R60
Introduction
SPARC is a matricellular protein, which, along with other extracellular matrix components including collagens, is commonly over-expressed in fibrotic diseases. The purpose of this study was to examine whether inhibition of SPARC can regulate collagen expression in vitro and in vivo, and subsequently attenuate fibrotic stimulation by bleomycin in mouse skin and lungs. 相似文献12.
Background
Burkholderia pseudomallei is the causative agent for melioidosis, a disease with significant mortality and morbidity in endemic regions. Its versatility as a pathogen is reflected in its relatively huge 7.24 Mb genome and the presence of many virulence factors including three Type Three Secretion Systems known as T3SS1, T3SS2 and T3SS3. Besides being a human pathogen, it is able to infect and cause disease in many different animals and alternative hosts such as C. elegans. 相似文献13.
Gene expression variation in African and European populations of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>
下载免费PDF全文
![点击此处可从《Genome biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Background
Differences in levels of gene expression among individuals are an important source of phenotypic variation within populations. Recent microarray studies have revealed that expression variation is abundant in many species, including Drosophila melanogaster. However, previous expression surveys in this species generally focused on a small number of laboratory strains established from derived populations. Thus, these studies were not ideal for population genetic analyses. 相似文献14.
15.
Background
Evolutionary analyses of the largest subunit of RNA polymerase II (RPB1) have yielded important and at times provocative results. One particularly troublesome outcome is the consistent inference of independent origins of red algae and green plants, at odds with the more widely accepted view of a monophyletic Plantae comprising all eukaryotes with primary plastids. If the hypothesis of a broader kingdom Plantae is correct, then RPB1 trees likely reflect a persistent phylogenetic artifact. To gain a better understanding of RNAP II evolution, and the presumed artifact relating to green plants and red algae, we isolated and analyzed RPB 1 from representatives of Glaucocystophyta, the third eukaryotic group with primary plastids. 相似文献16.
Background
Chitosanases are enzymes hydrolysing chitosan, a β-1,4 linked D-glucosamine bio-polymer. Chitosan oligosaccharides have numerous emerging applications and chitosanases can be used for industrial enzymatic hydrolysis of chitosan. These extracellular enzymes, produced by many organisms including fungi and bacteria, are well studied at the biochemical and enzymatic level but very few works were dedicated to the regulation of their gene expression. This is the first study on the genetic regulation of a heterologous chitosanase gene (csnN106) in Streptomyces lividans. 相似文献17.
Kung Ahn Jae-Won Huh Sang-Je Park Dae-Soo Kim Hong-Seok Ha Yun-Ji Kim Ja-Rang Lee Kyu-Tae Chang Heui-Soo Kim 《BMC molecular biology》2008,9(1):78
Background
The rhesus monkey (Macaca mulatta) is a valuable and widely used model animal for biomedical research. However, quantitative analyses of rhesus gene expression profiles under diverse experimental conditions are limited by a shortage of suitable internal controls for the normalization of mRNA levels. In this study, we used a systematic approach for the selection of potential reference genes in the rhesus monkey and compared their suitability to that of the corresponding genes in humans. 相似文献18.
19.
Megan K Townsend Nathan J Carr Jyoti G Iyer Shelley M Horne Penelope S Gibbs Birgit M Prüß 《BMC microbiology》2008,8(1):12