86 research outputs found

    Land plant molecular Phylogenetics: a review with comments on evaluating incongruence among Phylogenies

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    Land plants evolved from freshwater charophyte algal ancestors during a single transition to the terrestrial environment. The six major lineages of land plants are divided into two groups, the bryophytes (liverworts, mosses, and hornworts) and the tracheophytes (lycophytes, ferns, and seed plants), but while the tracheophytes are thought to be monophyletic, the bryophytes have typically been considered as the direct ancestors of tracheophytes and therefore an artificial, nonmonophyletic, group. Here the molecular phylogenetic evidence for relationships is reviewed and evaluated especially in-light of large genome-level studies that have been completed in the last few years. Consideration is given to how to evaluate competing hypotheses with respect to the underlying evolutionary assumptions of the models used to analyse the molecular data, and the degrees of support for particular hypotheses. It is concluded that currently the two most-favourable hypotheses are that the bryophytes are a monophyletic group, or that a lineage consisting of liverworts and mosses branched first among land plants with the hornworts the most-closely related lineage to tracheophytes. Although hitherto rarely considered, the possible monophyly of bryophytes has important implications for the morphological reconstruction of the last common ancestor of all land plants. Indeed, it might suggest that the ancestor of land plants was vascularised and had alternating generations that were more isomorphic than is found in extant taxa. The evolution of the bryophytes might then have proceeded through elaboration of the gametophyte and reduction of the sporophyte, while the opposite being true of the tracheophyte lineage.Portuguese Foundation for Science and Technology PTDC/BIA-EVF/1499/2014, CCMAR/Multi/04326/2013info:eu-repo/semantics/publishedVersio

    The chloroplast land plant phylogeny: analyses employing better-fitting tree- and site-heterogeneous composition models

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    The colonization of land by descendants of charophyte green algae marked a turning point in Earth history that enabled the development of the diverse terrestrial ecosystems we see today. Early land plants diversified into three gametophyte-dominant lineages, namely the hornworts, liverworts, and mosses, collectively known as bryophytes, and a sporophyte-dominant lineage, the vascular plants, or tracheophytes. In recent decades, the prevailing view of evolutionary relationships among these four lineages has been that the tracheophytes were derived from a bryophyte ancestor. However, recent phylogenetic evidence has suggested that bryophytes are monophyletic, and thus that the first split among land plants gave rise to the lineages that today we recognize as the bryophytes and tracheophytes. We present a phylogenetic analysis of chloroplast protein-coding data that also supports the monophyly of bryophytes. This newly compiled data set consists of 83 chloroplast genes sampled across 30 taxa that include chlorophytes and charophytes, including four members of the Zygnematophyceae, and land plants, that were sampled following a balanced representation of the main bryophyte and tracheophyte lineages. Analyses of non-synonymous site nucleotide data and amino acid translation data result in congruent phylogenetic trees showing the monophyly of bryophytes, with the Zygnematophyceae as the charophyte group most closely related to land plants. Analyses showing that bryophytes and tracheophytes evolved separately from a common terrestrial ancestor have profound implications for the way we understand the evolution of plant life cycles on land and how we interpret the early land plant fossil record.This work was supported by FCT (Portuguese Foundation for Science and Technology) through project grant PTDC/BIA-EVF/1499/2014 to CC and national funds through project UIDB/04326/2020, and from the operational programs CRESC Algarve 2020 and COMPETE 2020 through projects EMBRC.PT ALG-01-0145-FEDER-022121 and BIODATA.PT ALG-01-0145-FEDER-022231.info:eu-repo/semantics/publishedVersio

    A haplotype-resolved draft genome of the European sardine (Sardina pilchardus)

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    The European sardine (Sardina pilchardus Walbaum, 1792) is culturally and economically important throughout its distribution. Monitoring studies of sardine populations report an alarming decrease in stocks due to overfishing and environmental change, which has resulted in historically low captures along the Iberian Atlantic coast. Important biological and ecological features such as population diversity, structure, and migratory patterns can be addressed with the development and use of genomics resources.Agência financiadora Portuguese national funds from FCT-Foundation for Science and Technology: UID/Multi/04326/2016; European Regional Development Fund (FEDER): 22153-01/SAICT/2016; ALG-01-0145-FEDER-022121; ALG-01-0145-FEDER-022231; MAR2020 operational programme of the European Maritime and Fisheries Fund (project SARDI-NOMICS): MAR-01.04.02-FEAMP-0024; European Union's Horizon 2020 research and innovation programme: 654008info:eu-repo/semantics/publishedVersio

    The mitochondrial phylogeny of land plants shows support for Setaphyta under composition-heterogeneous substitution models

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    Congruence among analyses of plant genomic data partitions (nuclear, chloroplast and mitochondrial) is a strong indicator of accuracy in plant molecular phylogenetics. Recent analyses of both nuclear and chloroplast genome data of land plants (embryophytes) have, controversially, been shown to support monophyly of both bryophytes (mosses, liverworts, and hornworts) and tracheophytes (lycopods, ferns, and seed plants), with mosses and liverworts forming the clade Setaphyta. However, relationships inferred from mitochondria are incongruent with these results, and typically indicate paraphyly of bryophytes with liverworts alone resolved as the earliest-branching land plant group. Here, we reconstruct the mitochondrial land plant phylogeny from a newly compiled data set. When among-lineage composition heterogeneity is accounted for in analyses of codon-degenerate nucleotide and amino acid data, the clade Setaphyta is recovered with high support, and hornworts are supported as the earliest-branching lineage of land plants. These new mitochondrial analyses demonstrate partial congruence with current hypotheses based on nuclear and chloroplast genome data, and provide further incentive for revision of how plants arose on land.UIDB/04326/2020, PTDC/BIA-EVF/1499/2014, EMBRC.PT ALG-01-0145-FEDER-022121, BIODATA.PT ALG-01-0145-FEDER-022231info:eu-repo/semantics/publishedVersio

    Genomic blueprints of sponge-prokaryote symbiosis are shared by low abundant and cultivatable Alphaproteobacteria

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    Marine sponges are early-branching, filter-feeding metazoans that usually host complex microbiomes comprised of several, currently uncultivatable symbiotic lineages. Here, we use a low-carbon based strategy to cultivate low-abundance bacteria from Spongia officinalis. This approach favoured the growth of Alphaproteobacteria strains in the genera Anderseniella, Erythrobacter, Labrenzia, Loktanella, Ruegeria, Sphingorhabdus, Tateyamaria and Pseudovibrio, besides two likely new genera in the Rhodobacteraceae family. Mapping of complete genomes against the metagenomes of S. officinalis, seawater, and sediments confirmed the rare status of all the above-mentioned lineages in the marine realm. Remarkably, this community of low-abundance Alphaproteobacteria possesses several genomic attributes common to dominant, presently uncultivatable sponge symbionts, potentially contributing to host fitness through detoxification mechanisms (e.g. heavy metal and metabolic waste removal, degradation of aromatic compounds), provision of essential vitamins (e.g. B6 and B12 biosynthesis), nutritional exchange (especially regarding the processing of organic sulphur and nitrogen) and chemical defence (e.g. polyketide and terpenoid biosynthesis). None of the studied taxa displayed signs of genome reduction, indicative of obligate mutualism. Instead, versatile nutrient metabolisms along with motility, chemotaxis, and tight-adherence capacities - also known to confer environmental hardiness - were inferred, underlying dual host-associated and free-living life strategies adopted by these diverse sponge-associated Alphaproteobacteria.PTDC/MAR-BIO/1547/2014; full PhD scholarship from the Erasmus Mundus Programme/SALAM EMA2 lot7/SALA1206422info:eu-repo/semantics/publishedVersio

    Prokaryotic diversity in stream sediments affected by acid mine drainage

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    The microbial communities in mining impacted areas rely on a variety of mechanisms to survive in such extreme environments. In this work, a meta-taxonomic approach using 16S rRNA gene sequences was used to investigate the prokaryotic diversity of sediment samples from water bodies affected by acid mine drainage at the Sao Domingos mining area in the south of Portugal. Samples were collected in summer and winter from the most contaminated sites from where the water flows downstream to the freshwater of Chanca's river reservoir. The prokaryotic diversity on water bodies' sediments allowed us to distinguish the highly contaminated sites (pH approximate to 2) from sites with intermediate levels of contamination (pH approximate to 3-6.5), and from sites without contamination (pH approximate to 7.5). The abundances of acidophiles of generaAcidiphilium, Acidibacter, Acidobacterium and Acidocellain the sediments were correlated with the level of acid mine drainage contamination. The two first genera were among the 30 most abundant prokaryotes in all contaminated samples, including one (SS2w), where the contamination was very diluted, thereby emphasizing the impact that such type of pollution can have in the microbial communities of sediments. In addition, the high abundances of archaeal taxa from classThermoplasmataand of bacteria from family RCP1-48 in the sediments from the most contaminated site corroborate their importance in such ecosystems and a putative role in the generation of acid mine drainage.Portuguese national funds from the Foundation for Science and Technology (FCT) [UIDB/04326/2020]FCTPortuguese Foundation for Science and TechnologyEuropean Commission [29251]Algarve's Regional Operational Program (CRESC Algarve 2020), through Portugal 2020European Regional Development Fund (FEDER)European CommissionEuropean Regional Development Fund ERDFEuropean Commission [0483_PROBIOMA_5_E]info:eu-repo/semantics/publishedVersio

    Comparative mitogenomic analyses and gene rearrangements reject the alleged polyphyly of a bivalve genus

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    Background: The order and orientation of genes encoded by animal mitogenomes are typically conserved, although there is increasing evidence of multiple rearrangements among mollusks. The mitogenome from a Brazilian brown mussel (hereafter named B1) classified as Perna perna Linnaeus, 1758 and assembled from Illumina short-length reads revealed an unusual gene order very different from other congeneric species. Previous mitogenomic analyses based on the Brazilian specimen and other Mytilidae suggested the polyphyly of the genus Perna. Methods: To confirm the proposed gene rearrangements, we sequenced a second Brazilian P. perna specimen using the "primer-walking" method and performed the assembly using as reference Perna canaliculus. This time-consuming sequencing method is highly effective when assessing gene order because it relies on sequentially-determined, overlapping fragments. We also sequenced the mitogenomes of eastern and southwestern South African P. perna lineages to analyze the existence of putative intraspecific gene order changes as the two lineages show overlapping distributions but do not exhibit a sister relationship. Results: The three P. perna mitogenomes sequenced in this study exhibit the same gene order as the reference. CREx, a software that heuristically determines rearrangement scenarios, identified numerous gene order changes between B1 and our P. perna mitogenomes, rejecting the previously proposed gene order for the species. Our results validate the monophyly of the genus Perna and indicate a misidentification of B1.info:eu-repo/semantics/publishedVersio

    Improved phylogeny of brown algae Cystoseira (Fucales) from the Atlantic- Mediterranean region based on mitochondrial sequences

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    Cystoseira is a common brown algal genus widely distributed throughout the Atlantic and Mediterranean regions whose taxonomical assignment of specimens is often hampered by intra- and interspecific morphological variability. In this study, three mitochondrial regions, namely cytochrome oxidase subunit 1 (COI), 23S rDNA (23S), and 23S-tRNAVal intergenic spacer (mt-spacer) were used to analyse the phylogenetic relationships of 22 Cystoseira taxa (n = 93 samples). A total of 135 sequences (48 from COI, 43 from 23S and 44 from mtspacer) were newly generated and analysed together with Cystoseira sequences (9 COI, 31 23S and 35 mt-spacer) from other authors. Phylogenetic analysis of these three markers identified 3 well-resolved clades and also corroborated the polyphyletic nature of the genus. The resolution of Cystoseira taxa within the three clades improves significantly when the inclusion of specimens of related genera was minimized. COI and mt-spacer markers resolved the phylogeny of some of the Cystoseira taxa, such as the C. baccata, C. foeniculacea and C. usneoides. Furthermore, trends between phylogeny, embryonic development and available chemotaxonomic classifications were identified, showing that phylogenetic, chemical and morphological data should be taken into account to study the evolutionary relationships among the algae currently classified as Cystoseira. The resolution of Cystoseira macroalgae into three well supported clades achieved here is relevant for a more accurate isolation and identification of natural compounds and the implementation of conservation measures for target species. PLOS ON
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