Read by QxMD icon Read

Journal of Phycology

Masakazu Hoshino, Tatsufumi Okino, Kazuhiro Kogame
In isogamous brown algae, the sexuality of populations needs to be tested by laboratory crossing experiments, as the sexes of gametophytes are morphologically indistinguishable. In some cases, gamete fusion is not observed and the precise reproductive mode of the populations is unknown. In the isogamous brown alga Scytosiphon lomentaria in Japan, both asexual (gamete fusion is unobservable) and sexual populations (gamete fusion is observable) have been reported. In order to elucidate the reproductive mode of asexual populations in this species, we used PCR-based sex markers to investigate the sex ratio of three asexual and two sexual field populations...
November 9, 2018: Journal of Phycology
Dongseok Kim, JunMo Lee, Ji Won Choi, Ji Hyun Yang, Il-Ki Hwang, Hwan Su Yoon
To better understand organelle genome evolution of the ulvophycean green alga Capsosiphon fulvescens, we sequenced and characterized its complete chloroplast genome. The circular chloroplast genome was 111,561 bp in length with 31.3% GC content that contained 108 genes including 77 protein-coding genes, two copies of rRNA operons, and 27 tRNAs. In this analysis, we found the two types of isoform, called heteroplasmy, were likely caused by a flip-flop organization. The flip-flop mechanism may have caused structural variation and gene conversion in the chloroplast genome of C...
November 7, 2018: Journal of Phycology
Maxim Kulikovskiy, Yevhen Maltsev, Svetlana Andreeva, Anton Glushchenko, Evgeniy Gusev, Yulia Podunay, Thelma Veiga Ludwig, Eduardo Tusset, John Patrick Kociolek
Type material of Navicula kotschyi was studied, and this species was transferred to Dorofeyukea gen. nov. as D. kotschyi comb. nov. Dorofeyukea was described on the basis of DNA sequence and morphological data. Additional species assigned to this genus that were previously included in Navicula include: D. ancisa comb. nov., D. grimmei comb. nov., D. ivatoensis comb. nov., D. orangiana comb. nov., D. rostellata comb. nov. & stat. nov., D. savannahiana comb. nov., D. tenuipunctata comb. nov. and D. texana comb...
October 31, 2018: Journal of Phycology
Poh-Kheng Ng, Yu-Shan Chiou, Li-Chia Liu, Zhongmin Sun, Hiromori Shimabukuro, Showe-Mei Lin
The evolutionary influences of historical and contemporary factors on the population connectivity and phylogeographic structure of a brown seaweed, Sargassum ilicifolium, were elucidated using the nuclear ITS2 and mitochondrial COI markers for the collections newly sampled within its distribution range in the northwestern Pacific (NWP). Significant genetic structure at variable levels was identified between populations (pairwise FST ) and among populations grouped by geographical proximity (ΦCT among regions)...
October 29, 2018: Journal of Phycology
Xiao Jing Xu, Zuo Yi Chen, Nina Lundholm, Yang Li
Monoclonal strains of Chaetoceros species were established from Chinese warm waters. Vegetative cells and resting spores were examined using light microscopy, as well as scanning and transmission electron microscopy. Combined morphological and DNA sequence data from the hypervariable D1-D3 region of the nuclear ribosomal large subunit showed the presence of two new species within the section Compressa, herein described as Chaetoceros bifurcatus sp. nov. and C. millipedarius sp. nov. Both species possessed features typical of the section Compressa, but C...
October 28, 2018: Journal of Phycology
Sophie Steinhagen, Andrea Barco, Thomas Wichard, Florian Weinberger
As one of the most abundant and ubiquitous representatives of marine and brackish coastal macrophytobenthos communities, the genus Ulva is not only an important primary producer but also of ecological and morphogenetic interest to many scientists. Ulva mutabilis became an important model organism to study morphogenesis and mutualistic interactions of macroalgae and microorganisms. Here we report that our collections of Ulva compressa Linnaeus (1753) from Germany are conspecific with the type strains of the model organism Ulva mutabilis Føyn (1958), which were originally collected at Olhão on the south coast of Portugal and have from that time on been maintained in culture as gametophytic and parthenogenetic lab strains...
October 26, 2018: Journal of Phycology
Mariéllen Dornelles Martins, Náthali Maria Machado-de-Lima, Luis Henrique Zanini Branco
A new Phormidium-like genus was found during an investigation of Oscillatoriales diversity in Brazil. Eight aerophytic populations from south and southeastern regions were isolated in monospecific cultures and submitted to polyphasic evaluation. The populations presented homogeneous morphology with straight trichomes, not attenuated, and apical cell with thickened cell wall. Phylogenetic analyses based on 16S rRNA gene sequences showed that these populations, plus the Brazilian strain Phomidium sp. B-Tom from GenBank, formed a highly supported and distinctive clade, which corresponds to the new genus Pycnacronema, comprising six new species: P...
October 26, 2018: Journal of Phycology
Benwen Liu, Qian Xiong, Xudong Liu, Guoxiang Liu, Zhengyu Hu
The broadly defined genus Chaetophora consisted of species with minute, uniseriate branching filaments enveloped in soft or firm mucilage forming macroscopic growths that are spherical, hemispherical, tubercular or arbuscular, growing epiphytically on freshwater aquatic plants and other submerged surfaces in standing or fast-flowing water. Recent molecular analyses clearly showed that this genus was polyphyletic. In this study, eight strains of Chaetophora and three strains of Stigeoclonium were identified and successfully cultured...
October 22, 2018: Journal of Phycology
Ga Hun Boo, Jeffery R Hughey
Molecular surveys are leading to the discovery of many new cryptic species of marine algae. This is particularly true for red algal intertidal species, which exhibit a high degree of morphological convergence. DNA sequencing of recent collections of Gelidium along the coast of California, USA, identified two morphologically similar entities that differed in DNA sequence from existing species. To characterize the two new species of Gelidium and to determine their evolutionary relationships to other known taxa, phylogenomic, multigene analyses, and morphological observations were performed...
October 19, 2018: Journal of Phycology
Nour Ayache, Fabienne Hervé, Véronique Martin-Jézéquel, Zouher Amzil, Amandine M N Caruana
Several coastal countries including France have experienced serious and increasing problems related to Pseudo-nitzschia toxic blooms. These toxic blooms occur in estuarine and coastal waters potentially subject to fluctuations in salinity. In this study, we document for the first time the viability, growth, photosynthetic efficiency and toxin production of two strains of Pseudo-nitzschia australis grown under conditions with sudden salinity changes. Following salinity variation, the two strains survived over a restricted salinity range of 30 to 35, with favorable physiological responses, as the growth, effective quantum yield and toxin content were high compared to the other conditions...
October 17, 2018: Journal of Phycology
Kazumasa Yamada, Hirotaka Katsura, Mary-Hélène Noël, Mutsuo Ichinomiya, Akira Kuwata, Shinya Sato, Shinya Yoshikawa
Triparma laevis f. inornata is a unicellular alga belonging to the Bolidophyceae, which is most closely related to diatoms. Like diatoms, T. laevis f. inornata has a siliceous cell wall. The cell wall of T. laevis f. inornata consists of four round plates (three shields and one ventral plate) and one dorsal and three girdle plates. But, unlike diatoms, T. laevis f. inornata cells can grow when concentrations of silica are depleted. We took advantage of this ability, using TEM to study the ontogeny of the siliceous plate, pattern center formation and development...
October 15, 2018: Journal of Phycology
Viviana Peña, Line Le Gall, Anja Rösler, Claude E Payri, Juan Carlos Braga
Adeylithon gen. nov. with one species, A. bosencei sp. nov., belonging to the subfamily Hydrolithoideae is described from Pacific coral reefs based on psbA sequences and morpho-anatomy. In contrast with Hydrolithon, A. bosencei showed layers of large polygonal "cells", which resulted from extensive lateral fusions of perithallial cells, interspersed among layers of vegetative cells. This anatomical feature is shared with the fossil Aethesolithon, but lacking DNA sequences from the fossils and the fragmentary nature of Aethesolithon type material, we cannot ascertain if Adeylithon and Aethesolithon are congeneric...
October 13, 2018: Journal of Phycology
Luca Rugiu, Iita Manninen, Eva Rothäusler, Veijo Jormalainen
To predict the effects of climate change, we first need information on both the current tolerance ranges of species and their future adaptive potential. Adaptive responses may originate either in genetic variation or in phenotypic plasticity, but the relative importance of these factors is poorly understood. Here, we tested the tolerance of Fucus radicans to the combination of hyposalinity and warming projected by climate models for 2070-2099. We measured the growth and survival responses of thalli in both current and future conditions, focusing on variations in tolerance among and within different clonal lineages...
October 13, 2018: Journal of Phycology
Dwiyantari Widyaningrum, Daisuke Iida, Yuma Tanabe, Yasuko Hayashi, Sari Dewi Kurniasih, Takeshi Ohama
Nanoparticles have unique properties that make them attractive for use in industrial and medical technology industries but can also be harmful to living organisms, making an understanding of their molecular mechanisms of action essential. We examined the effect of three different sized poly(isobutyl-cyanoacrylate) nanoparticles (iBCA-NPs) on the unicellular green alga Chlamydomonas reinhardtii. We found that exposure to iBCA-NPs immediately caused C. reinhardtii to display abnormal swimming behaviors. Furthermore, after one hour, most of the cells had stopped swimming and 10-30% of cells were stained with trypan blue, suggesting that these cells had severely impaired plasma membranes...
October 10, 2018: Journal of Phycology
María García-Portela, Pilar Riobó, Beatriz Reguera, José Luis Garrido, Juan Blanco, Francisco Rodríguez
Dinoflagellates of the genus Dinophysis are the most persistent producers of lipophilic shellfish toxins in Western Europe. Their mixotrophic nutrition requires a food chain of cryptophytes and plastid-bearing ciliates for sustained growth and photosynthesis. In this study, cultures of D. acuminata and D. acuta, their ciliate prey Mesodinium rubrum and the cryptophyte, Teleaulax amphioxeia, were subject to three experimental settings to study their physiological response to different combinations of light intensity and quality...
October 8, 2018: Journal of Phycology
John W Stiller, Chunlin Yang, Jonas Collén, Nathalie Kowalczyk, Beth E Thompson
Red algae are the oldest identifiable multicellular eukaryotes, with a fossil record dating back more than a billion years. During that time two major rhodophyte lineages, bangiophytes and florideophytes, have evolved varied levels of morphological complexity. These two groups are distinguished, in part, by different patterns of multicellular development, with florideophytes exhibiting a far greater diversity of morphologies. Interestingly, during their long evolutionary history, there is no record of a rhodophyte achieving the kinds of cellular and tissue-specific differentiation present in other multicellular algal lineages...
October 4, 2018: Journal of Phycology
An Suk Lim, Hae Jin Jeong, Ji Eun Kwon, Sung Yeon Lee, Ji Hye Kim
The planktonic phototrophic dinoflagellate Gonyaulax whaseongensis sp. nov., isolated from coastal waters of western Korea, was described from living and fixed cells under light and scanning electron microscopy, and its rDNA was sequenced. Gonyaulax whaseongensis had a plate formula of 2pr, 4', 6'', 6c, 6''', 1p, and 1'''' with S-type ventral organization like the other species in the genus. However, this dinoflagellate had a narrow cingulum (ca. 2.6 μm), small displacement of the cingulum, slight overhang and steep angle between the ends of the cingulum, quadrangular sixth precingular plate, reticulated cell surface without longitudinal lines or ridges, and two unequal antapical spines, together which distinguish this from all other reported Gonyaulax species...
October 1, 2018: Journal of Phycology
Marianne Kreusch, Elisa Poltronieri, Fernanda Bouvie, Deonir Batista, Débora T Pereira, Fernanda Ramlov, Marcelo Maraschin, Zenilda L Bouzon, Éder Carlos Schmidt, Carmen Simioni
Ocean warming is increasing and scientific predictions suggest a rise of up to 4°C in sea water temperatures. The combination of a polluted and warmer environment may be detrimental for aquatic species, especially for primary producers such as seaweeds. This study investigated the potential for interactive effects of an increased seawater temperature in a copper-rich environment on the photosynthetic pigments and metabolic compounds of the red seaweed Gelidium floridanum. Seaweed samples were cultivated in a factorial design with temperature (24°C and 30°C), copper (0 and 3 μM), and time (7 and 14 d)...
October 1, 2018: Journal of Phycology
Yang Li, Huan Chang Dong, Sing Tung Teng, Stephen S Bates, Po Teen Lim
Pseudo-nitzschia nanaoensis sp. nov. is described from waters around Nan'ao Island (South China Sea), using morphological data and molecular evidence. This species is morphologically most similar to P. brasiliana, but differs by a denser arrangement of fibulae, interstriae, and poroids, as well as by the structure of the valvocopula and the narrow second band. Pseudo-nitzschia nanaoensis constitutes a monophyletic lineage and is well differentiated from other species on the LSU and ITS2 sequence-structure trees...
October 1, 2018: Journal of Phycology
Linda E Graham
Known Proterozoic algal fossils raise compelling questions about the origin and diversification of cyanobacteria and eukaryotic algae, and their ecological influence in deep time. This Perspectives article describes particular examples of persistent evolutionary and biogeochemical issues whose resolution would be aided by additional algal fossil evidence from Proterozoic deposits, which have been the subjects of recent intensive study. New Proterozoic geosciences literature relevant to the early diversification of algae is surveyed...
October 1, 2018: Journal of Phycology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"