Phycological Research最新文献

{"title":"Evolutionary analysis of MID homologs during the transition from homothallic species to heterothallic species in Volvox sect. Volvox (Chlorophyceae)","authors":"Shion Yamagishi, Kayoko Yamamoto, Kohei Takahashi, Hiroko Kawai-Toyooka, Shigekatsu Suzuki, Ryo Matsuzaki, Haruyo Yamaguchi, Masanobu Kawachi, Tetsuya Higashiyama, Hisayoshi Nozaki","doi":"10.1111/pre.12538","DOIUrl":"https://doi.org/10.1111/pre.12538","url":null,"abstract":"The diversity and the evolution of mating systems have been studied in various eukaryotes. <i>Volvox</i> sect. <i>Volvox</i> of the volvocine green algae is suitable for evolutionary studies of the transition from homothallic to heterothallic mating systems because this transition is recognized in distal lineages within <i>Volvox</i> sect. <i>Volvox</i>. <i>MID</i> homologs are important in determining the mating type minus and male in heterothallic species of the volvocine algae. However, <i>MID</i> homologs have not been studied within the entire <i>Volvox</i> sect. <i>Volvox</i>. Here, we analyzed <i>MID</i> homologs from almost all taxa of <i>Volvox</i> sect. <i>Volvox</i> and found no significant differences in <i>MID</i> sequences between homothallic species and males of heterothallic species. Furthermore, <i>MID</i> of the male genotype of the heterothallic <i>Volvox rousseletii</i> showed an expression pattern that was almost identical to that of a closely related homothallic species, <i>Volvox ferrisii</i>. Therefore, the function of <i>MID</i> might have been conserved within the ancestral homothallic lineage of <i>Volvox</i> sect. <i>Volvox</i> and during the evolutionary transition of the heterothallic male genotype from the ancestral homothallic species, possibly related to male gametogenesis.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"122 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138507448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trentepohlia brevicellulis comb. et stat. nov. (Trentepohliaceae, Ulvophyceae) found in Japan","authors":"Shinji Handa, Miho Nakahara-Tsubota, Izumi Shoda, Aya Mizobuchi, Taketo Nakano, Hiromi Tsubota","doi":"10.1111/pre.12537","DOIUrl":"https://doi.org/10.1111/pre.12537","url":null,"abstract":"The family Trentepohliaceae contains many common aerial algae, most widely distributed, particularly in tropical and subtropical regions. Eight species of the genus <i>Trentepohlia</i> have been reported in Japan. We report another taxon, <i>Trentepohlia brevicellulis</i> (Cribb) S. Handa and H. Tsubota comb. et stat. nov., growing on bark in western Honshu, Japan. This alga was previously described as <i>Trentepohlia bosseae</i> var. <i>brevicellulis</i> Cribb. However, the relationship between the <i>bosseae</i> and <i>brevicellulis</i> varieties of <i>T. bosseae</i> could not be ascertained owing to the lack of genetic information for <i>brevicellulis</i>. Therefore, we aimed to examine the detailed morphological characteristics of <i>brevicellulis</i> in wild samples and cultured strains and to review the taxonomy, including systematic information obtained by genetic analysis. Its phylogenetic position was resolved based on 18S rDNA sequence data. It differs from <i>T. bosseae</i> and its variety <i>samoensis</i> in exhibiting a warty zoosporangium surface, an unthickened septum with no central pit field, and a non-rusty-brown cell wall. The four key characteristics of <i>T. brevicellulis</i> include a warty layer on the inner surface of the non-bent side of the suffultory cell wall, an ostiole located near the base of the zoosporangium, curved tapering filaments with thickened cell walls, and globular vegetative spores in the basal portion of the filament. Transmission electron microscopy revealed a pit field wherein simple plasmodesmata were present in the septum. Phylogenetic analysis suggested that this alga and <i>T. bosseae</i> form distinct clades and that <i>T. brevicellulis</i> is separate from <i>T. bosseae</i>. Thus, our study helped redefine the accurate taxonomic position of the species under study as <i>Trentepohlia brevicellulis</i> (Cribb) S. Handa and H. Tsubota comb. et stat. nov., a clade distinct from <i>T. bosseae</i> and reported for the first time in Japan.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"116 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138507454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Swimming zygote formation mediated by symmetrically arranged cell fusion sites in the gametes of <i>Chlamydomonas eugametos</i> (<scp>Chlorophyceae, Chlorophyta</scp>)","authors":"Shinichi Miyamura","doi":"10.1111/pre.12535","DOIUrl":"https://doi.org/10.1111/pre.12535","url":null,"abstract":"SUMMARY The spatial arrangement of cell fusion sites and eyespots of the gametes in vis‐à‐vis mating pairs of Chlamydomonas eugametos , corresponding to the swimming zygote of Chlamydomonas reinhardtii , were studied using field emission scanning electron microscopy and light microscopy, respectively. After the adhesion of mt + and mt − gametes, each of which has one eyespot and two flagella elongated from the cell anterior, gamete–gamete fusion occurred at the anterior papilla on the cell apex of each gamete, leading to the formation of a vis‐à‐vis mating pair, indicating that the cell fusion site is arranged symmetrically relative to the flagellar beat plane. In vis‐à‐vis mating pairs, two eyespots could be seen on the same or on opposite sides of the cell. As only the mt + flagella and eyespot are functional for swimming and phototaxis in the vis‐à‐vis mating pair of C. eugametos , it is suggested that coordinated alignment of the parental gamete flagella and eyespots in the swimming zygote and asymmetric positioning of the gamete mating structure/cell fusion sites, which is prevalent in C. reinhardtii and other chlorophytes, is not necessary for C. eugametos .","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"81 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135634959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular and morphological characterization of three novel <i>Minorisa</i> species (Chlorarachnea) and proposal for an emended description of the <i>Minorisa minuta</i>","authors":"Takashi Shiratori, Yuta Kato, Ken‐ichiro Ishida","doi":"10.1111/pre.12533","DOIUrl":"https://doi.org/10.1111/pre.12533","url":null,"abstract":"SUMMARY Minorisa is a group of tiny uniflagellates belonging to the Cercozoa. These flagellates are the closest heterotrophic relatives of photosynthetic chlorarachniophytes and are one of the most abundant bacterivorous eukaryotes in coastal marine environments. Despite their evolutionary and ecological importance, taxonomic studies on Minorisa have not been conducted since the original description. In the present study, we isolated five Minorisa strains and performed molecular phylogenetic and microscopic analyses. Molecular phylogenetic analysis using small subunit ribosomal RNA gene sequences indicated that the strains form four different subclades in Minorisa . Microscopic observations revealed that these Minorisa strains possess an amoeboid stage that lacks a flagellum. In the amoeboid stage, cells possess lobose and/or extrusive pseudopodia. Based on the phylogenetic analysis and morphological observations, we revised the description of Minorisa and described the following three novel Minorisa species: Minorisa fusiformis sp. nov., Minorisa magna sp. nov. and Minorisa megafusiformis sp. nov.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135944117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular study of the rare genus <scp><i>Neoabbottiella</i></scp> (Rhodophyta) reveals its assignment to the Halymeniaceae is incorrect","authors":"Anna V. Skriptsova, Oksana S. Belous, Svetlana Yu. Shibneva, Alexander A. Semenchenko","doi":"10.1111/pre.12534","DOIUrl":"https://doi.org/10.1111/pre.12534","url":null,"abstract":"SUMMARY The rare red algal genus Neoabbottiella from the Russian Pacific coast was taxonomically re‐examined. Currently, Neoabbottiella is assigned to the Halymeniales; however, some features of the reproductive anatomy cast doubt on the correctness of assigning the genus to Halymeniaceae sensu lato . We investigated the phylogenetic affinities of Neoabbottiella using four DNA markers (nuclear LSU and SSU rDNA, rbc L and COI‐5P). Neoabbottiella failed to group with any families of the Halymeniales, but it was nested in a highly supported clade containing representatives of the genus Schmitzia (Calosiphoniaceae incertae sedis ). Reproductive anatomy and post‐fertilization development also separate Neoabbottiella from the Halymeniaceae. The main characteristics distinguishing Neoabbottiella from the Halymeniales include the intercalary position of the auxiliary cell, the contact of the connecting filament with the auxiliary cell via the lateral process, the origin of the initial gonimoblast cell from the connecting filament at a distance from the auxiliary cell and a lack of a pericarp of branched ampullar filaments. These traits bring Neoabbottiella close to its genetic sister genus Schmitzia , making the classification of Neoabbottiella at the family and order levels difficult. The eventual taxonomic classification of Neoabbottiella awaits the input of data of other species of Schmitzia as well as Calosiphonia , the type genus of the Calosiphoniaceae; thus, Neoabbottiella should be provisionally excluded from the Halymeniales and considered as incertae sedis in the Rhodymeniophycidae. Further, the results of the present study showed that Neoabbottiella is monotypic; Neoabbottiella decipiens should be recognized as a synonym of the generitype Neoabbottiella araneosa .","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136079047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Referees","authors":"","doi":"10.1111/pre.12532","DOIUrl":"https://doi.org/10.1111/pre.12532","url":null,"abstract":"","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134934393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of cell wall polysaccharide from Cladosiphon okamuranus cultivated in different locations","authors":"M. Awanthi, Natsuki Nakasone, H. Oku, K. Kitahara, Michihiro Ito, Atsuko Tanaka, Yoichi Sato, Yuichiro Numata, T. Konishi","doi":"10.1111/pre.12531","DOIUrl":"https://doi.org/10.1111/pre.12531","url":null,"abstract":"Cladosiphon okamuranus is an excellent source of fucoidan among any brown algae spp. However, the structure of polysaccharide varies significantly depending on the species, harvesting season and geographical location. To understand how geographic location affects the structure of cell wall polysaccharide, C. okamuranus cultivated in eight places (Bise, Katsuren, Yonashiro, Shikiya, Karimata, Nishihara, Hisamatsu and Ishigaki) in Ryukyu archipelago were collected during the peak harvesting time and the cell wall polysaccharide was analyzed physiochemically. The cell wall was sequentially fractionated into five fractions and its 80% was consisted of hot water fraction (HW) (60–70%) and hemicellulose‐I fraction (HC‐I) (15–20%), which mainly contained fucoidan composed of fucose (Fuc), glucuronic acid (GlcA) and sulfate (SO3−). Although the chemical composition and molecular weight of fucoidan in HW was slightly different at different places, the composition of Fuc, GlcA and SO3− was constant in the molar ratio of 1.0:0.5:0.7–1.0 respectively, suggesting that relatively similar structural fucoidan from C. okamuranus can be obtained from any geographical location in Okinawa Prefecture during peak time. However, considerable variation in the sugar composition in HC‐I was observed, despite the uniform molecular weight and SO3−. Particularly, HC‐I from Bise, where is the northern part of Okinawa Island, is composed of significantly higher amounts of Glc, Gal, Man, Xyl and morphologically thicker lateral branches compared to algae from the other parts of the island.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41862042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composition of galactolipids, betaine lipids and triglyceride‐associated fatty acids of the symbiotic dinoflagellate Zooxanthella (Brandtodinium) nutricula: A glimpse into polyunsaturated fatty acids available to its polycystine radiolarian host","authors":"Jori E. Graeff, Jeffrey D. Leblond","doi":"10.1111/pre.12530","DOIUrl":"https://doi.org/10.1111/pre.12530","url":null,"abstract":"Zooxanthella nutricula is a photosynthetic dinoflagellate symbiont of polycystine radiolarians. As such, it is hypothesized to provide fixed organic carbon, including in the form of acylglycerolipids and sterols, to its non‐photosynthetic host. We have previously characterized the sterols of Z. nutricula that may be transferred to its host and, in the present study, have turned our attention to three classes of fatty acid‐containing lipids, chloroplast‐associated galactolipids, betaine lipids, which are non‐phosphorylated phospholipid analogs present in many eukaryotes, and triglycerides. Zooxanthella nutricula was observed using positive‐ion electrospray/mass spectrometry (ESI/MS) and ESI/MS/MS to produce the galactolipids mono‐ and digalactosyldiacylglycerol (MGDG and DGDG, respectively) enriched in octadecapentaenoic (18:5(n‐3)) and octadecatetraenoic (18:4(n‐3)) acid to place it within a group of peridinin‐containing dinoflagellates in a C18/C18 (sn‐1/sn‐2 fatty acid regiochemistry) cluster, as opposed to another cluster with C20/C18 MGDG and DGDG, where the C20 fatty acid is eicosapentaenoic acid (20:5(n‐3)) and the C18 fatty acid is either 18:5(n‐3) or 18:4(n‐3). Zooxanthella nutricula was also observed to produce 38:10 (total number of fatty acid carbons:total number of double bonds), 38:6, and 44:7 diacylglycerylcarboxyhydroxymethylcholine (DGCC) as the sole type of betaine lipid. Although it is more difficult to determine which fatty acids are present in the sn‐1 and sn‐2 positions on the glycerol backbone of DGCC using ESI/MS/MS, gas chromatography/mass spectrometry (GC/MS)‐based examination indicated the putatively DGCC‐associated polyunsaturated fatty acid (PUFA) docosahexaenoic acid (22:6(n‐3)). Coupled with the C18 PUFAs of MGDG and DGDG, and fatty acids associated with triglycerides (also examined via GC/MS), Z. nutricula could serve as a rich source of PUFAs for its radiolarian host. These data demonstrate that Z. nutricula produces a similar set of PUFA‐containing lipids as Symbiodinium microadriaticum, a photosynthetic dinoflagellate symbiont of cnidarians, indicating a metabolic commonality in these phylogenetically discrete dinoflagellate symbionts with unrelated host organisms.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43717201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat shock and iron limitation modulate the metabolic profile of the cyanobacterium Microcystis aeruginosa NIES‐88","authors":"Nandani Balloo, Jakia Jerin Mehjabin, Chin-Soon Phan, T. Okino","doi":"10.1111/pre.12529","DOIUrl":"https://doi.org/10.1111/pre.12529","url":null,"abstract":"The freshwater cyanobacterium Microcystis aeruginosa NIES‐88, which can produce microcystins, micropeptins, and argicyclamides, was subjected to a one strain many compounds (OSMAC) analysis. We report its response to two environmental stressors, temperature and iron limitation, by means of untargeted and targeted metabolomics. The results demonstrated a slower specific growth rate of 0.20 per day and 0.16 per day in adverse conditions of 37°C and iron limitation, respectively. The metabolic signature of M. aeruginosa was highly dependent on incubation temperatures. Production of microcystins LR and RR was severely downregulated while that of argicyclamide B was significantly upregulated, with a highest 10‐fold increase on day 14 of heat shock treatment. M. aeruginosa NIES‐88 was found to produce a new compound, argicyclamide D (1), in iron limited medium, which has the same macrocyclic structure as the previously reported analogs. Hence, it is proposed that acclimation of M. aeruginosa to environmental stressors might be mediated by a change in the metabolic pathways as well as modulation of the levels of their expressed metabolites.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43229916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Betaine lipids of Symbiodiniaceae hosted by Indo‐Pacific corals","authors":"T. V. Sikorskaya, E. Ermolenko, P. Long","doi":"10.1111/pre.12528","DOIUrl":"https://doi.org/10.1111/pre.12528","url":null,"abstract":"The total pool of coral lipids consists of lipids produced by both the coral host and its symbiotic dinoflagellates of the family Symbiodiniaceae. Betaine lipids (BL) are characteristic of plasma membranes of microalgae. Composition of such BL as 1,2‐diacylglyceryl‐3‐O‐carboxy‐(hydroxymethyl)‐choline (DGCC) that occur in coral symbionts may depend on either Symbiodiniaceae species or coral species. Membrane‐forming lipids DGCC have a zwitterion structure similar to that of phosphatidylcholine (PC). They can substitute for each other to a substantial extent, certainly in relation to membrane functions. In the present study, the profiles of DGCC and diacyl PC molecular species of symbiotic dinoflagellates from Acropora sp., Millepora platyphylla and Sinularia flexibilis were determined by high‐performance liquid chromatography with high‐resolution mass‐spectrometry. Colonies of Acropora sp. were characterized by higher contents of DGCC with eicosapentaenoic acid (20:5n‐3) and C28 polyunsaturated fatty acids; S. flexibilis, by a higher content of DGCC with palmitic acid (16:0); and M. platyphylla, by a higher content of DGCC with docosahexaenoic acid (22:6n‐3). Although the DGCC profile of the corals under study has distinctive features, it shows both similarities with and differences from the DGCC profiles of previously studied corals. Probably, each coral symbiont species has its own specific DGCC molecular species profile that is additionally modified in a certain way depending on environmental conditions created by the coral host. Molecular species DGCC and PC profiles were different. The most abundant PC molecular species were 16:0/22:5 and 38:4 in Acropora sp.; 39:5 and 38:4 in S. flexibilis; and 38:6, 16:0/22:5 and 18:0/22:6 in M. platyphylla. Thus, there is no clear evidence for any compensation or interchangeability between PC and DGCC.","PeriodicalId":20544,"journal":{"name":"Phycological Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46736297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}