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1.
J Phycol ; 59(1): 221-235, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36336979

RESUMO

Partial rbcL sequences from type specimens of three of the earliest described Corallina species showed that C. arbuscula (type locality: Unalaska Island, Alaska, USA) and C. pilulifera (type locality: Okhotsk Sea, Russia) are synonymous, with C. pilulifera as the taxonomically accepted name and that C. vancouveriensis (type locality: Botanical Beach, Vancouver Island, Canada) is a distinct species. To identify molecular species limits and clarify descriptions and distributions of C. pilulifera and C. vancouveriensis, we sequenced and analyzed portions of one mitochondrial and two plastid genes from historical and recent collections. The single-gene phylogenetic reconstructions support the recognition of both species as distinct, as well as two additional species, C. hakodatensis sp. nov. and C. parva sp. nov., which are sister to, and often morphologically indistinguishable from C. pilulifera and C. vancouveriensis, respectively. DNA sequence data currently illustrate that C. pilulifera is found in the cold northern Pacific waters from the Okhotsk Sea of Russia to Hokkaido, Japan, eastward across the Aleutian Islands to Knoll Head, Alaska, and as far south as Nanaimo, British Columbia. Corallina vancouveriensis is distributed as far west as Attu Island in the Aleutian Islands to Sitka, Alaska, and southeasterly at numerous sites from British Columbia to the north of Point Conception, California, USA. The cryptic species C. hakodatensis and C. parva occur sympatrically with their sister species but with narrower ranges. The complex phylogenetic relationships shown by the single gene trees recommend Corallina as a model genus to explore coralline algal biogeography, evolution, and patterns of speciation.


Assuntos
Rodófitas , Filogenia , Análise de Sequência de DNA , Colúmbia Britânica , Japão
2.
Front Plant Sci ; 13: 849476, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35720545

RESUMO

We investigated the globally distributed red algal genus Pterocladiella, comprising 24 described species, many of which are economically important sources of agar and agarose. We used DNA-based species delimitation approaches, phylogenetic, and historical biogeographical analyses to uncover cryptic diversity and infer the drivers of biogeographic patterns. We delimited 43 species in Pterocladiella, of which 19 are undescribed. Our multigene time-calibrated phylogeny and ancestral area reconstruction indicated that Pterocladiella most likely originated during the Early Cretaceous in the Tethys Sea. Ancient Tethyan vicariance and long-distance dispersal have shaped current distribution patterns. The ancestor of Eastern Pacific species likely arose before the formation of the formidable Eastern Pacific Barrier-a first confirmation using molecular data in red algae. Divergences of Northeast and Southeast Pacific species have been driven by the Central American Seaway barrier, which, paradoxically, served as a dispersal pathway for Atlantic species. Both long- and short-distance dispersal scenarios are supported by genetic relationships within cosmopolitan species based on haplotype analysis. Asymmetrical distributions and the predominance of peripatry and sympatry between sister species suggest the importance of budding speciation in Pterocladiella. Our study highlights the underestimation of global diversity in these crucial components of coastal ecosystems and provides evidence for the complex evolution of current species distributions.

3.
Microorganisms ; 10(4)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35456869

RESUMO

We have isolated a chlorophyll-d-containing cyanobacterium from the intertidal field site at Moss Beach, on the coast of Central California, USA, where Manning and Strain (1943) originally discovered this far-red chlorophyll. Here, we present the cyanobacterium's environmental description, culturing procedure, pigment composition, ultrastructure, and full genome sequence. Among cultures of far-red cyanobacteria obtained from red algae from the same site, this strain was an epiphyte on a brown macroalgae. Its Qyin vivo absorbance peak is centered at 704-705 nm, the shortest wavelength observed thus far among the various known Acaryochloris strains. Its Chl a/Chl d ratio was 0.01, with Chl d accounting for 99% of the total Chl d and Chl a mass. TEM imagery indicates the absence of phycobilisomes, corroborated by both pigment spectra and genome analysis. The Moss Beach strain codes for only a single set of genes for producing allophycocyanin. Genomic sequencing yielded a 7.25 Mbp circular chromosome and 10 circular plasmids ranging from 16 kbp to 394 kbp. We have determined that this strain shares high similarity with strain S15, an epiphyte of red algae, while its distinct gene complement and ecological niche suggest that this strain could be the closest known relative to the original Chl d source of Manning and Strain (1943). The Moss Beach strain is designated Acaryochloris sp. (marina) strain Moss Beach.

4.
Plants (Basel) ; 10(11)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34834631

RESUMO

Cosmopolitan Acrosorium species with hook-forming thalli have been merged under the name of Acrosorium ciliolatum (Harvey) Kylin through a long and complicated nomenclatural history. We examined the specimens of 'A. ciliolatum' and related taxa from the northwestern (NW) Pacific, the UK, southern Spain, Australia, New Zealand, and Chile, using morphological and molecular analyses. We confirmed that these specimens are separated into four clades based on rbcL phylogeny, and the absence or presence of terminal hook-like structures represent intraspecific variation. Our results indicated that Acrosorium flabellatum Yamada, Cryptopleura hayamensis Yamada, Cryptopleura membranacea Yamada and the entities known as 'A. ciliolatum' in the NW Pacific are conspecific; the name A. flabellatum is the oldest and has priority. This taxon exhibits extreme variations in external blade morphology. We also confirmed that the position of the tetrasporangial sori is a valuable diagnostic characteristic for distinguishing A. flabellatum in the NW Pacific. We also discussed the need for further study of European and southern hemisphere specimens from type localities, as well as the ambiguous position of California specimens.

5.
J Phycol ; 57(1): 370-378, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33179252

RESUMO

Here, we report for the first time the presence of Dictyota cyanoloma in southern California. Dictyota cyanoloma is conspicuous in harbors and bays by its distinctive bright blue-iridescent margins. This species was originally described from Europe, but subsequent studies have revealed that it represented an introduction from Australia. The current distribution of D. cyanoloma comprises southern Australia and the North East Atlantic, including the Mediterranean Sea and the Macaronesian islands. The presence of D. cyanoloma in southern California is supported by molecular cox1 and psbA gene sequences. A reconstruction of the invasive history based on nine polymorphic microsatellite markers reveals a close affinity of the Californian specimens with European populations. Dictyota cyanoloma in the United States appears to be (so far) restricted to the Californian coast from San Diego Bay in the south to Santa Catalina Island and Long Beach Harbor in the north. A correlative species distribution model suggests gradually declining habitat suitability north of the Southern Californian Bight and high suitability in Baja California, including the Gulf of California. Finally, its widespread abundance in bays and harbors suggests shipping is a likely transport mechanism.


Assuntos
Phaeophyceae , Austrália , California , Europa (Continente) , Mar Mediterrâneo , México
6.
J Phycol ; 55(6): 1319-1334, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31390066

RESUMO

The evolutionary and population demographic history of marine red algae in East Asia is poorly understood. Here, we reconstructed the phylogeographies of two upper intertidal species endemic to East Asia, Gelidiophycus divaricatus and G. freshwateri. Phylogenetic and phylogeographic inferences of 393 mitochondrial cox1, 128 plastid rbcL, and 342 nuclear ITS2 sequences were complemented with ecological niche models. Gelidiophycus divaricatus, a southern species adapted to warm water, is characterized by a high genetic diversity and a strong geographical population structure, characteristic of stable population sizes and sudden reduction to recent expansion. In contrast, G. freshwateri, a northern species adapted to cold temperate conditions, is genetically relatively homogeneous with a shallow population structure resulting from steady population growth and recent equilibrium. The overlap zone of the two species roughly matches summer and winter isotherms, indicating that surface seawater temperature is a key feature influencing species range. Unidirectional genetic introgression was detected at two sites on Jeju Island where G. divaricatus was rare while G. freshwateri was common, suggesting the occurrence of asymmetric natural hybrids, a rarely reported event for rhodophytes. Our results illustrate that Quaternary climate oscillations have left strong imprints on the current day genetic structure and highlight the importance of seawater temperature and sea level change in driving speciation in upper intertidal seaweed species.


Assuntos
Rodófitas , Ásia , DNA Mitocondrial , Estruturas Genéticas , Variação Genética , Haplótipos , Filogenia , Filogeografia
7.
J Phycol ; 55(3): 503-508, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30907438

RESUMO

Current usage of the name Ulva lactuca, the generitype of Ulva, remains uncertain. Genetic analyses were performed on the U. lactuca Linnaean holotype, the U. fasciata epitype, the U. fenestrata holotype, the U. lobata lectotype, and the U. stipitata lectotype. The U. lactuca holotype is nearly identical in rbcL sequence to the epitype of U. fasciata, a warm temperate to tropical species, rather than the cold temperate species to which the name U. lactuca has generally been applied. We hypothesize that the holotype specimen of U. lactuca came from the Indo-Pacific rather than northern Europe. Our analyses indicate that U. fasciata and U. lobata are heterotypic synonyms of U. lactuca. Ulva fenestrata is the earliest name for northern hemisphere, cold temperate Atlantic and Pacific species, with U. stipitata a junior synonym. DNA sequencing of type specimens provides an unequivocal method for applying names to Ulva species.


Assuntos
Clorófitas , Ulva , Europa (Continente) , Análise de Sequência de DNA
8.
J Phycol ; 54(2): 249-263, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29315605

RESUMO

The genus Ptilophora currently includes 16 species occurring mostly in subtidal habitats of the Indo-Pacific Ocean, but its global diversity and biogeography are poorly understood. We analyzed mitochondrial cox1, plastid rbcL and plastid psbA sequences from specimens collected in southern Madagascar during the 2010 Atimo Vatae expedition and studied their morphologies. Both morphological and molecular data sets demonstrated the presence of five species in southern Madagascar: Ptilophora hildebrandtii, P. pterocladioides, and three new species described here, P. aureolusa, P. malagasya, and P. spongiophila. Ptilophora aureolusa is distinguished by its compound pinnae with uniformly spaced pinnules. Ptilophora malagasya has an indistinct midrib and irregularly spaced pinnules. Ptilophora spongiophila, heavily coated with sponges, has cylindrical to flattened main axes, lateral and surface proliferations, and spatulate tetrasporangial sori. The species of Ptilophora found in Madagascar are endemic, except P. hildebrandtii, which also occurs in eastern Africa. Ptilophora comprises four phylogenetic groups that map to eastern Australia, Japan, western Australia/Southeast Asia/Madagascar/eastern Africa, and Madagascar/eastern Africa/Aegean Sea. Biogeographical analysis revealed that the ancestor of Ptilophora originated in Australia, but most of the species radiated from Madagascar.


Assuntos
Dispersão Vegetal , Rodófitas/classificação , Rodófitas/fisiologia , Proteínas de Algas/análise , Oceano Índico , Madagáscar , Oceano Pacífico , Filogenia , Filogeografia , Rodófitas/genética
9.
Mitochondrial DNA B Resour ; 3(2): 1302-1303, 2018 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33474501

RESUMO

An unknown species of marine sea lettuce was observed forming green tides consecutive years from 2014 to 2016 in Seaside, California. This Ulva sp. was similar in thallus size and shape to U. expansa. To confirm this identification, whole genome sequencing was performed on the bloom-forming species of Ulva and the holotype specimen of U. expansa. The complete green tide Ulva mitogenome is 64,143 bp in length, contains 65 genes, and displays high gene synteny with U. pertusa Kjellman. The mitogenome was incomplete for the holotype of U. expansa, but the analysis yielded the mitoexome, plastid, and nuclear genetic markers. These data verify that the native U. expansa is responsible for the blooms in central California.

10.
PLoS One ; 12(11): e0187104, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29095864

RESUMO

Coccophora langsdorfii (Turner) Greville (Fucales) is an intertidal brown alga that is endemic to Northeast Asia and increasingly endangered by habitat loss and climate change. We sequenced the complete circular plastid and mitochondrial genomes of C. langsdorfii. The circular plastid genome is 124,450 bp and contains 139 protein-coding, 28 tRNA and 6 rRNA genes. The circular mitochondrial genome is 35,660 bp and contains 38 protein-coding, 25 tRNA and 3 rRNA genes. The structure and gene content of the C. langsdorfii plastid genome is similar to those of other species in the Fucales. The plastid genomes of brown algae in other orders share similar gene content but exhibit large structural recombination. The large in-frame insert in the cox2 gene in the mitochondrial genome of C. langsdorfii is typical of other brown algae. We explored the effect of this insertion on the structure and function of the cox2 protein. We estimated the usefulness of 135 plastid genes and 35 mitochondrial genes for developing molecular markers. This study shows that 29 organellar genes will prove efficient for resolving brown algal phylogeny. In addition, we propose a new molecular marker suitable for the study of intraspecific genetic diversity that should be tested in a large survey of populations of C. langsdorfii.


Assuntos
Marcadores Genéticos , Genoma Mitocondrial , Phaeophyceae/genética , Plastídeos/genética , Códon , Phaeophyceae/classificação , Filogenia
11.
J Phycol ; 53(2): 368-380, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28078674

RESUMO

Morphological, anatomical, and molecular sequence data were used to assess the establishment and phylogenetic position of the genus Wilsonosiphonia gen. nov. Phylogenies based on rbcL and concatenated rbcL and cox1 loci support recognition of Wilsonosiphonia gen. nov., sister to Herposiphonia. Diagnostic features for Wilsonosiphonia are rhizoids located at distal ends of pericentral cells and taproot-shaped multicellular tips of rhizoids. Wilsonosiphonia includes three species with diagnostic rbcL and cox1 sequences, Wilsonosiphonia fujiae sp. nov. (the generitype), W. howei comb. nov., and W. indica sp. nov. These three species resemble each other in external morphology, but W. fujiae is distinguished by having two tetrasporangia per segment rather than one, W. indica by having abundant and persistent trichoblasts, and W. howei by having few and deciduous trichoblasts.


Assuntos
Rodófitas/genética , DNA Ribossômico , Filogenia , Rodófitas/classificação , Análise de Sequência de DNA
12.
J Phycol ; 53(2): 261-270, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28078742

RESUMO

We confirmed the monophyly of the Agaraceae based on phylogenetic analyses of six mitochondrial and six chloroplast gene sequences from Agarum, Costaria, Dictyoneurum, and Thalassiophyllum species, as well as representative species from other laminarialean families. However, the genus Agarum was paraphyletic, comprising two independent clades, A. clathratum/A. turneri and A. fimbriatum/A. oharaense. The latter clade was genetically most closely related to Dictyoneurum spp., and morphologically, the species shared a flattened stipe bearing fimbriae (potential secondary haptera) in the mid- to upper portion. The phylogenetic position of Thalassiophyllum differed between the two datasets: in the chloroplast gene phylogeny, Thalassiophyllum was included in the A. clathratum/A. turneri clade, but in the mitochondrial gene phylogeny, it formed an independent clade at the base of the Agaraceae, the same position it took in the phylogeny when the data from both genomes were combined despite a larger number of bp being contributed by the chloroplast gene sequences. Considering the remarkable morphological differences between Thalassiophyllum and other Agaraceae, and the molecular support, we conclude that Thalassiophyllum should be reinstated as an independent genus. Dictyoneurum reticulatum was morphologically distinguishable from D. californicum due to its midrib, but because of their close genetic relationship, further investigations are needed to clarify species-level taxonomy. In summary, we propose the establishment of a new genus Neoagarum to accommodate A. fimbriatum and A. oharanese and the reinstatement of the genus Thalassiophyllum.


Assuntos
Phaeophyceae/genética , Genes de Cloroplastos/genética , Genes Mitocondriais/genética , Phaeophyceae/classificação , Filogenia
13.
BMC Evol Biol ; 17(1): 30, 2017 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-28114901

RESUMO

BACKGROUND: Molecular markers are revealing a much more diverse and evolutionarily complex picture of marine biodiversity than previously anticipated. Cryptic and/or endemic marine species are continually being found throughout the world oceans, predominantly in inconspicuous tropical groups but also in larger, canopy-forming taxa from well studied temperate regions. Interspecific hybridization has also been found to be prevalent in many marine groups, for instance within dense congeneric assemblages, with introgressive gene-flow being the most common outcome. Here, using a congeneric phylogeographic approach, we investigated two monotypic and geographically complementary sister genera of north-east Pacific intertidal seaweeds (Hesperophycus and Pelvetiopsis), for which preliminary molecular tests revealed unexpected conflicts consistent with unrecognized cryptic diversity and hybridization. RESULTS: The three recovered mtDNA clades did not match a priori species delimitations. H. californicus was congruent, whereas widespread P. limitata encompassed two additional narrow-endemic species from California - P. arborescens (here genetically confirmed) and P. hybrida sp. nov. The congruence between the genotypic clusters and the mtDNA clades was absolute. Fixed heterozygosity was apparent in a high proportion of loci in P. limitata and P. hybrida, with genetic analyses showing that the latter was composed of both H. californicus and P. arborescens genomes. All four inferred species could be distinguished based on their general morphology. CONCLUSIONS: This study confirmed additional diversity and reticulation within NE Pacific Hesperophycus/Pelvetiopsis, including the validity of the much endangered, modern climatic relict P. arborescens, and the identification of a new, stable allopolyploid species (P. hybrida) with clearly discernable ancestry (♀ H. californicus x ♂ P. arborescens), morphology, and geographical distribution. Allopolyploid speciation is otherwise completely unknown in brown seaweeds, and its unique occurrence within this genus (P. limitata possibly representing a second example) remains enigmatic. The taxonomic separation of Hesperophycus and Pelvetiopsis is not supported and the genera should be synonymized; we retain only the latter. The transitional coastline between Point Conception and Monterey Bay represented a diversity hotspot for the genus and the likely sites of extraordinary evolutionary events of allopolyploid speciation at sympatric range contact zones. This study pinpoints how much diversity (and evolutionary processes) potentially remains undiscovered even on a conspicuous seaweed genus from the well-studied Californian intertidal shores let alone in other, less studied marine groups and regions/depths.


Assuntos
Alga Marinha/genética , Animais , Biodiversidade , Evolução Biológica , California , DNA Mitocondrial/genética , Fluxo Gênico , Oceano Pacífico , Filogenia , Filogeografia , Poliploidia , Alga Marinha/classificação , Análise de Sequência de DNA
14.
J Phycol ; 53(1): 32-43, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27690326

RESUMO

Next generation sequence data were generated and used to assemble the complete plastomes of the holotype of Membranoptera weeksiae, the neotype (designated here) of M. tenuis, and a specimen examined by Kylin in making the new combination M. platyphylla. The three plastomes were similar in gene content and length and showed high gene synteny to Calliarthron, Grateloupia, Sporolithon, and Vertebrata. Sequence variation in the plastome coding regions were 0.89% between M. weeksiae and M. tenuis, 5.14% between M. weeksiae and M. platyphylla, and 5.18% between M. tenuis and M. platyphylla. We were unable to decipher the complete mitogenomes of the three species due to low coverage and structural problems; however, we assembled and analyzed, the cytochrome oxidase I, II, and III loci and found that M. weeksiae and M. tenuis differed in sequence by 1.3%, M. weeksiae and M. platyphylla by 8.4%, and M. tenuis and M. platyphylla by 8.1%. Evaluation of standard marker genes indicated that sequences from the rbcL, RuBisCO spacer, and CO1 genes closely approximated the pair-wise genetic distances observed between the plastomes of the three species of Membranoptera. A phylogenetic tree based on rbcL sequences showed that M. tenuis and M. weeksiae were sister taxa. Short rbcL sequences were obtained from type specimens of M. dimorpha, M. multiramosa, and M. edentata and confirmed their conspecificity with M. platyphylla. The data support the recognition of three species of Membranoptera occurring south of Alaska: M. platyphylla, M. tenuis, and M. weeksiae.


Assuntos
Proteínas de Algas/genética , Genoma de Planta , Genomas de Plastídeos , Rodófitas/genética , Sequência de Bases , América do Norte , Oceano Pacífico , Filogenia , Rodófitas/classificação , Ribulose-Bifosfato Carboxilase/genética , Alinhamento de Sequência , Especificidade da Espécie
15.
Sci Rep ; 6: 35337, 2016 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-27739454

RESUMO

DNA sequences from type specimens provide independent, objective characters that enhance the value of type specimens and permit the correct application of species names to phylogenetic clades and specimens. We provide mitochondrial genomes (mitogenomes) from archival type specimens of ten species in agar-producing red algal genera Gelidium and Pterocladiella. The genomes contain 43-44 genes, ranging in size from 24,910 to 24,970 bp with highly conserved gene synteny. Low Ka/Ks ratios of apocytochrome b and cytochrome oxidase genes support their utility as markers. Phylogenies of mitogenomes and cox1+rbcL sequences clarified classification at the genus and species levels. Three species formerly in Gelidium and Pterocladia are transferred to Pterocladiella: P. media comb. nov., P. musciformis comb. nov., and P. luxurians comb. and stat. nov. Gelidium sinicola is merged with G. coulteri because they share identical cox1 and rbcL sequences. We describe a new species, Gelidium millariana sp. nov., previously identified as G. isabelae from Australia. We demonstrate that mitogenomes from type specimens provide a new tool for typifying species in the Gelidiales and that there is an urgent need for analyzing mitogenomes from type specimens of red algae and other morphologically simple organisms for insight into their nomenclature, taxonomy and evolution.


Assuntos
Genoma Mitocondrial/genética , Filogenia , Rodófitas/genética , Ágar/química , Ágar/metabolismo , Austrália , Genótipo , Rodófitas/metabolismo
16.
Mol Phylogenet Evol ; 101: 359-372, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27223999

RESUMO

Although the Gelidiales are economically important marine red algae producing agar and agarose, the phylogeny of this order remains poorly resolved. The present study provides a molecular phylogeny based on a novel marker, nuclear-encoded CesA, plus plastid-encoded psaA, psbA, rbcL, and mitochondria-encoded cox1 from subsets of 107 species from all ten genera within the Gelidiales. Analyses of individual and combined datasets support the monophyly of three currently recognized families, and reveal a new clade. On the basis of these results, the new family Orthogonacladiaceae is described to accommodate Aphanta and a new genus Orthogonacladia that includes species previously classified as Gelidium madagascariense and Pterocladia rectangularis. Acanthopeltis is merged with Gelidium, which has nomenclatural priority. Nuclear-encoded CesA was found to be useful for improving the resolution of phylogenetic relationships within the Gelidiales and is likely to be valuable for the inference of phylogenetic relationship among other red algal taxa.


Assuntos
Núcleo Celular/genética , Filogenia , Rodófitas/classificação , Rodófitas/genética , Marcadores Genéticos , Funções Verossimilhança , Rodófitas/anatomia & histologia
17.
Sci Rep ; 6: 23744, 2016 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-27030297

RESUMO

The integration of foreign DNA into algal and plant plastid genomes is a rare event, with only a few known examples of horizontal gene transfer (HGT). Plasmids, which are well-studied drivers of HGT in prokaryotes, have been reported previously in red algae (Rhodophyta). However, the distribution of these mobile DNA elements and their sites of integration into the plastid (ptDNA), mitochondrial (mtDNA), and nuclear genomes of Rhodophyta remain unknown. Here we reconstructed the complex evolutionary history of plasmid-derived DNAs in red algae. Comparative analysis of 21 rhodophyte ptDNAs, including new genome data for 5 species, turned up 22 plasmid-derived open reading frames (ORFs) that showed syntenic and copy number variation among species, but were conserved within different individuals in three lineages. Several plasmid-derived homologs were found not only in ptDNA but also in mtDNA and in the nuclear genome of green plants, stramenopiles, and rhizarians. Phylogenetic and plasmid-derived ORF analyses showed that the majority of plasmid DNAs originated within red algae, whereas others were derived from cyanobacteria, other bacteria, and viruses. Our results elucidate the evolution of plasmid DNAs in red algae and suggest that they spread as parasitic genetic elements. This hypothesis is consistent with their sporadic distribution within Rhodophyta.


Assuntos
DNA Mitocondrial/genética , DNA de Plantas/genética , Evolução Molecular , Genomas de Plastídeos , Plasmídeos/metabolismo , Rodófitas/genética , Variações do Número de Cópias de DNA , Ontologia Genética , Transferência Genética Horizontal , Anotação de Sequência Molecular , Fases de Leitura Aberta , Filogenia , Plasmídeos/química , Plastídeos/genética , Rodófitas/classificação
18.
Am J Bot ; 102(11): 1912-30, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26542846

RESUMO

PREMISE OF THE STUDY: Phenotypic plasticity and convergent evolution have long complicated traditional morphological taxonomy. Fortunately, DNA sequences provide an additional basis for comparison, independent of morphology. Most importantly, by obtaining DNA sequences from historical type specimens, we are now able to unequivocally match species names to genetic groups, often with surprising results. METHODS: We used an integrative taxonomic approach to identify and describe Northeast Pacific pinnately branched species in the red algal coralline genus Bossiella, for which traditional taxonomy recognized only one species, the generitype, Bossiella plumosa. We analyzed DNA sequences from historical type specimens and modern topotype specimens to assign species names and to identify genetic groups that were different and that required new names. Our molecular taxonomic assessment was followed by a detailed morphometric analysis of each species. KEY RESULTS: Our study of B. plumosa revealed seven pinnately branched Bossiella species. Three species, B. frondescens, B. frondifera, and B. plumosa, were assigned names based on sequences from type specimens. The remaining four species, B. hakaiensis, B. manzae, B. reptans, and B. montereyensis, were described as new to science. In most cases, there was significant overlap of morphological characteristics among species. CONCLUSIONS: This study underscores the pitfalls of relying upon morpho-anatomy alone to distinguish species and highlights our likely underestimation of species worldwide. Our integrative taxonomic approach can serve as a model for resolving the taxonomy of other plant and algal genera.


Assuntos
Rodófitas/classificação , Sequência de Bases , DNA de Plantas/química , DNA de Plantas/genética , Evolução Molecular , Dados de Sequência Molecular , Rodófitas/anatomia & histologia , Rodófitas/genética , Análise de Sequência de DNA
19.
Sci Rep ; 4: 5113, 2014 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-24894641

RESUMO

Plant species, including algae and fungi, are based on type specimens to which the name of a taxon is permanently attached. Applying a scientific name to any specimen therefore requires demonstrating correspondence between the type and that specimen. Traditionally, identifications are based on morpho-anatomical characters, but recently systematists are using DNA sequence data. These studies are flawed if the DNA is isolated from misidentified modern specimens. We propose a genome-based solution. Using 4 × 4 mm(2) of material from type specimens, we assembled 14 plastid and 15 mitochondrial genomes attributed to the red algae Pyropia perforata, Py. fucicola, and Py. kanakaensis. The chloroplast genomes were fairly conserved, but the mitochondrial genomes differed significantly among populations in content and length. Complete genomes are attainable from 19(th) and early 20(th) century type specimens; this validates the effort and cost of their curation as well as supports the practice of the type method.


Assuntos
Mapeamento Cromossômico/métodos , Genoma Mitocondrial/genética , Genoma de Planta/genética , Genomas de Plastídeos/genética , Rodófitas/genética , Manejo de Espécimes/métodos , Sequência de Bases , Dados de Sequência Molecular
20.
J Phycol ; 50(5): 885-96, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26988642

RESUMO

The red alga Pachymeniopsis lanceolata, formerly known as Grateloupia lanceolata, is a component of the native algal flora of northeast Asia and has been introduced to European and North American waters. It has been confused with a cryptic species collected from Korea and Italy. Our analyses of rbcL, cox3 and ITS from P. lanceolata and this cryptic species has revealed two distinct entities, forming a clade, which were clearly separated from its congeners and positioned with other Asian species. Here, we describe the cryptic species as P. gargiuli sp. nov., a species that differs from others by molecular sequence and subtle anatomical characters. We hypothesize that P. gargiuli may have been recently dispersed by anthropogenic vectors, possibly at or near the same time as was P. lanceolata. Our cox3 data set revealed that one haplotype of P. gargiuli, shared between Korea and Italy, and two haplotypes of P. lanceolata, commonly occurring in Korea and USA, are invasive haplotypes. This is the first report of the utility of the mitochondrial coding cox3 sequences in red algae.

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