The diversity and the evolution of mating systems have been studied in various eukaryotes. Volvox sect. Volvox 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 Volvox sect. Volvox. MID homologs are important in determining the mating type minus and male in heterothallic species of the volvocine algae. However, MID homologs have not been studied within the entire Volvox sect. Volvox. Here, we analyzed MID homologs from almost all taxa of Volvox sect. Volvox and found no significant differences in MID sequences between homothallic species and males of heterothallic species. Furthermore, MID of the male genotype of the heterothallic Volvox rousseletii showed an expression pattern that was almost identical to that of a closely related homothallic species, Volvox ferrisii. Therefore, the function of MID might have been conserved within the ancestral homothallic lineage of Volvox sect. Volvox and during the evolutionary transition of the heterothallic male genotype from the ancestral homothallic species, possibly related to male gametogenesis.
人们对各种真核生物交配系统的多样性和进化进行了研究。volvoline green algae的Volvox节。volvoline green algae的Volvox节适合于从同属到异属交配系统过渡的进化研究，因为这种过渡在Volvox节的远端谱系中被认可。MID同系物在确定异源藻种的交配类型中具有重要意义。然而，在整个Volvox组中尚未研究MID同源物。在此，我们分析了几乎所有涡旋科分类群的MID同源性，发现同属种和异属种的雄性在MID序列上没有显著差异。此外，异thalic Volvox rousseletii雄性基因型的MID表达模式几乎与近亲同源物种Volvox ferrisii相同。因此，MID的功能可能在涡旋组的祖先同源谱系中以及在从祖先同源物种向异源雄性基因型的进化过渡过程中被保存下来，可能与雄性配子体发生有关。
{"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}
The family Trentepohliaceae contains many common aerial algae, most widely distributed, particularly in tropical and subtropical regions. Eight species of the genus Trentepohlia have been reported in Japan. We report another taxon, Trentepohlia brevicellulis (Cribb) S. Handa and H. Tsubota comb. et stat. nov., growing on bark in western Honshu, Japan. This alga was previously described as Trentepohlia bosseae var. brevicellulis Cribb. However, the relationship between the bosseae and brevicellulis varieties of T. bosseae could not be ascertained owing to the lack of genetic information for brevicellulis. Therefore, we aimed to examine the detailed morphological characteristics of brevicellulis 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 T. bosseae and its variety samoensis 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 T. brevicellulis 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 T. bosseae form distinct clades and that T. brevicellulis is separate from T. bosseae. Thus, our study helped redefine the accurate taxonomic position of the species under study as Trentepohlia brevicellulis (Cribb) S. Handa and H. Tsubota comb. et stat. nov., a clade distinct from T. bosseae and reported for the first time in Japan.
苔藻科包含许多常见的气生藻类，分布最广泛，特别是在热带和亚热带地区。在日本已报道了八种Trentepohlia属。我们报道了另一个分类群，Trentepohlia brevicellulis (Cribb) S. Handa和H. Tsubota comb。11月1日，生长在日本本州西部的树皮上。这种藻类以前被描述为Trentepohlia bosseae var. brevicellulis Cribb。然而，由于缺乏短细胞的遗传信息，一直无法确定其与短细胞品种之间的关系。因此，本研究旨在研究野生和培养菌株短微囊菌的详细形态特征，并对其分类进行综述，包括通过遗传分析获得的系统信息。根据18S rDNA序列数据确定其系统发育位置。它与T. bosseae及其变种samoensis的不同之处在于表现出有疣状的动物孢子囊表面，没有增厚的中隔，没有中央坑区，和非锈棕色的细胞壁。短毛霉的四个主要特征包括:在丰满细胞壁非弯曲侧的内表面有疣状层，位于虫孢子囊基部附近的气孔，弯曲的逐渐变细的细胞壁增厚的花丝，以及在花丝基部的球形营养孢子。透射电镜显示，在鼻中隔有一个凹陷区，其中有简单的胞间连丝。系统发育分析表明，该藻与波氏藻形成了不同的分支，短细胞藻与波氏藻是分离的。因此，我们的研究有助于重新确定所研究物种的准确分类位置，即Trentepohlia brevicellulis (Cribb) S. Handa和H. Tsubota comb。et stat.nov .，在日本首次报道的与T. bosseae不同的一个分支。
{"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}
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 .
{"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}
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.
小鞭毛纲是一组微小的单鞭毛纲动物，属于尾虫纲。这些鞭毛虫是光合绿蛛纲植物最近的异养亲戚，是沿海海洋环境中最丰富的细菌真核生物之一。尽管它们在进化和生态学上具有重要意义，但从最初的描述开始，对米诺瑞沙的分类研究就没有进行过。在本研究中，我们分离了5株Minorisa菌株并进行了分子系统发育和显微分析。利用小亚基核糖体RNA基因序列进行的分子系统发育分析表明，该菌株在Minorisa中形成了四个不同的亚支系。显微镜观察显示，这些Minorisa菌株具有一个变形虫阶段，缺乏鞭毛。在变形虫阶段，细胞具有叶状和/或挤压的假足。在系统发育分析和形态学观察的基础上，我们对该属植物的描述进行了修正，确定了3个新种:Minorisa fusiformis sp. nov.、Minorisa magna sp. nov.和Minorisa megafusiformis sp. nov.。
{"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}
Anna V. Skriptsova, Oksana S. Belous, Svetlana Yu. Shibneva, Alexander A. Semenchenko
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 .
对俄罗斯太平洋沿岸罕见的红藻属Neoabbottiella进行了分类学研究。目前，Neoabbottiella被分配给Halymeniales;然而，生殖解剖学上的一些特征使人怀疑将该属划归到Halymeniaceae sensu lato的正确性。我们利用四种DNA标记(核LSU和SSU rDNA，红细胞L和COI - 5P)研究了Neoabbottiella的系统进化亲缘性。Neoabbottiella没有归属于Halymeniales的任何科，但它被嵌套在一个高度支持的分支中，其中包括Schmitzia属(Calosiphoniaceae incertae sedis)的代表。生殖解剖和受精后发育也将Neoabbottiella与Halymeniaceae区分开来。Neoabbottiella与Halymeniales的主要区别在于辅助细胞的间质位置，连接丝与辅助细胞通过侧突接触，初始的成性腺细胞起源于距离辅助细胞一定距离的连接丝，以及缺乏壶腹分枝丝的果皮。这些特征使新阿伯提亚与其遗传姊妹属Schmitzia接近，使得新阿伯提亚在科和目水平上的分类变得困难。Neoabbottiella的最终分类有待于Schmitzia其他种以及Calosiphonia (Calosiphoniaceae的模式属)的资料输入;因此，Neoabbottiella应暂时排除在halymenicidae之外，并将其视为Rhodymeniophycidae中的incertae sesis。此外，本研究结果表明，新阿博特菌是单型的;新阿伯蒂菌应被认为是属型新阿伯蒂菌的同义词。
{"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}
M. Awanthi, Natsuki Nakasone, H. Oku, K. Kitahara, Michihiro Ito, Atsuko Tanaka, Yoichi Sato, Yuichiro Numata, T. Konishi
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.
{"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}
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.
{"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}
Nandani Balloo, Jakia Jerin Mehjabin, Chin-Soon Phan, T. Okino
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.
{"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}
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.
{"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}
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