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1.
Mol Ecol ; 31(11): 3210-3227, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35364623

RESUMO

The microbial communities of sandy beaches are poorly described despite the biogeochemical importance and ubiquity of these ecosystems. Using metabarcoding of the 16S and 18S rRNA genes, we investigated the diversity, microhabitats (with or between sand grains) and intertidal distributions of microorganisms (including meiofauna) from pristine sandy beaches in British Columbia, Canada, and hypothesized that abiotic variations due to microhabitat or intertidal gradients influence the distribution of microorganisms on local scales. Bacterial, archaeal and protistan communities of the sand were clearly distinct from interstitial communities, and from planktonic communities of the overlying seawater, which correlated with differences in function and lifestyle (e.g., sulphur reduction and gliding motility). In contrast, meiofaunal communities could not be distinguished by sample type, suggesting that they are more frequently mobilized between these microhabitats. Across intertidal zones, high intertidal, mid intertidal and low intertidal/swash communities were distinct and correlated with moisture, organic carbon and phosphate content, implying that the distribution of microorganisms is influenced by intertidal abiotic gradients. However, few taxa at the genus or species level individually contributed to this zonation pattern; rather, a unique combination of multiple microbial taxa was probably responsible. Although significant differences in microbial community composition on sandy beaches can be attributed to microhabitat and intertidal gradients, further investigations are needed to assess community assembly processes, the consistency of these distributions, and the functions of the majority of the microorganisms observed in the sand and their effects on the biogeochemistry and ecology of sandy beaches.


Assuntos
Ecossistema , Microbiota , Praias , Colúmbia Britânica , Microbiota/genética , Areia , Água do Mar
2.
AIDS Behav ; 26(5): 1633-1651, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34870772

RESUMO

We examined satisfaction and perceived challenges with antiretroviral therapy (ART) among people living with HIV (PLHIV) in Japan vs three other Asian countries (China, Taiwan, South Korea), and 21 non-Asian countries, using data from the 2019 Positive Perspectives Study (pooled sample size from all 25 countries = 2389). Participants in other Asian countries were more likely than those in Japan to report they missed ART ≥ 1 time in the past month because they were depressed/overwhelmed (57.4%[89/155] vs 32.0%[24/75]), had privacy concerns (56.8%[88/155] vs 30.7%[23/75]), were concerned about the potential long-term negative impacts of ART (46.5%[72/155] vs 26.7%[20/75]), or just wanted to forget about HIV (45.8%[71/155] vs 22.7%[17/75]). ART satisfaction however did not differ significantly between surveyed PLHIV in Japan (54.7%[41/75]) vs those in other Asian countries (47.7%[74/155]). The percentage who felt that daily ART dosing limited their lives was 36.0%[27/75] among participants from Japan, 48.4%[75/155] among participants from other Asian countries, and 27.3%[589/2159] among those from non-Asian countries. Within a structural equation model using pooled data from all 25 countries, positive correlations were seen between ART satisfaction and "provider engagement" (ß = 0.35), high perceived control over ART dosing schedule (ß = 0.28), and the belief that ART prevents HIV transmission (ß = 0.16). Conversely, negative correlations were seen between ART satisfaction and experience of ART side-effects (ß = - 0.24), high "ART anxiety" (ß = - 0.20); and being on multi-tablet regimens (ß = - 0.13). Those ART-satisfied reported higher self-rated health and greater ART adherence. These findings underscore the need for patient-centered care to enhance treatment satisfaction and improve ART adherence.


Assuntos
Infecções por HIV , Satisfação Pessoal , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Humanos , Japão/epidemiologia , Adesão à Medicação , Satisfação do Paciente
3.
J Eukaryot Microbiol ; : e12852, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33768669

RESUMO

Corals (Metazoa; Cnidaria; Anthozoa) have recently been shown to play host to a widespread and diverse group of intracellular symbionts of the phylum Apicomplexa. These symbionts, colloquially called "corallicolids", are mostly known through molecular analyses, and no formal taxonomy has been proposed. Another apicomplexan, Gemmocystis cylindrus (described from the coral Dendrogyra cylindrus), may be related to corallicolids, but lacks molecular data. Here, we isolate and describe motile trophozoite (feeding) corallicolids cells using microscopic (light, SEM, and TEM) and molecular phylogenetic analysis to provide the basis for a formal description. Phylogenetic analyses using nuclear and plastid rRNA operons, and three mitochondrial protein sequences derived from single cell transcriptomes, all confirm that these organisms fall into a discrete deep-branching clade within the Apicomplexa not closely related to any known species or major subgroup. As a result, we assign this clade to a new order, Corallicolida ord. nov., and family, Corallicolidae fam. nov. We describe a type species, Corallicola aquarius gen. nov. sp. nov. from its Rhodactis sp. host, and also describe a second species, Anthozoaphila gnarlus gen. nov. sp. nov., from the coral host Madracis mirabilis. Finally, we propose reassigning the incertae sedis taxon G. cylindrus from the order Agamococcidiorida to the Corallicolida, based on similarities in morphology and host localization to that of the corallicolids.

4.
Nihon Ronen Igakkai Zasshi ; 57(4): 458-466, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-33268631

RESUMO

AIM: Alcohol consumption is high in the colder regions of Russia, and it is related to poor sleep quality, mental and physical health problems. Little known on the actual situation, and no appropriate amount of drinking has been shown as a health guidance. The purpose of this study is to examine the relationship between alcohol consumption (in pure alcohol) and sleep among older people living in the Russian Siberian region, and the factors related to alcohol consumption. METHODS: A self-reported questionnaire survey was administered to 422 elderly over the age of 60 living in Novosibirsk, the central city of Siberia. Question items were basic attributes, health status, drinking habits, Short Form-8 Health Survey, Geriatric Depression Scale, and Pittsburgh Sleep Quality Index. For drinking elderly, daily amount of alcohol converted in pure alcohol was calculated, and logistic regression analysis among the two groups was compared based on the median value (32 g). RESULTS: The valid responses from the survey was 416 (98.9%). Of these, 293 with drinking habits were subjected to logistic regression analysis using pure alcohol (≥32 g/day) as the dependent variable. Significant relationships were found with gender (OR=0.586; 95%CI: 0.345-0.995), years of education (OR=1.538; 95%CI: 1.239-1.910), insomnia (OR=2.442; 95%CI: 1.185-5.032), alcohol intake, due to better sleep (OR=4.120; 95%CI: 1.044-16.258), effects of drinking, arousal during the night (OR=2.586; 95%CI: 1.317-5.077), effects of drinking, from family (OR=26.938; 95%CI: 3.368-215.431). CONCLUSIONS: Among the elderly people in colder regions of Russia, high alcohol consumption reduces sleep quality, suggesting the need for appropriate standards for pure alcohol and health education.


Assuntos
Consumo de Bebidas Alcoólicas , Sono , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/epidemiologia , Clima , Temperatura Baixa , Estudos Transversais , Humanos , Federação Russa/epidemiologia
5.
EMBO J ; 34(21): 2703-19, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26438722

RESUMO

Degradation of mitochondria via selective autophagy, termed mitophagy, contributes to mitochondrial quality and quantity control whose defects have been implicated in oxidative phosphorylation deficiency, aberrant cell differentiation, and neurodegeneration. How mitophagy is regulated in response to cellular physiology remains obscure. Here, we show that mitophagy in yeast is linked to the phospholipid biosynthesis pathway for conversion of phosphatidylethanolamine to phosphatidylcholine by the two methyltransferases Cho2 and Opi3. Under mitophagy-inducing conditions, cells lacking Opi3 exhibit retardation of Cho2 repression that causes an anomalous increase in glutathione levels, leading to suppression of Atg32, a mitochondria-anchored protein essential for mitophagy. In addition, loss of Opi3 results in accumulation of phosphatidylmonomethylethanolamine (PMME) and, surprisingly, generation of Atg8-PMME, a mitophagy-incompetent lipid conjugate of the autophagy-related ubiquitin-like modifier. Amelioration of Atg32 expression and attenuation of Atg8-PMME conjugation markedly rescue mitophagy in opi3-null cells. We propose that proper regulation of phospholipid methylation is crucial for Atg32-mediated mitophagy.


Assuntos
Proteínas Associadas aos Microtúbulos/metabolismo , Mitofagia , Fosfolipídeos/metabolismo , Receptores Citoplasmáticos e Nucleares/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomyces cerevisiae/metabolismo , Família da Proteína 8 Relacionada à Autofagia , Proteínas Relacionadas à Autofagia , Regulação Fúngica da Expressão Gênica , Humanos , Metilação , Mitocôndrias/metabolismo , Transporte Proteico , Saccharomyces cerevisiae/genética , Ativação Transcricional
6.
J Eukaryot Microbiol ; 66(4): 574-581, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30444565

RESUMO

Spores of the dinoflagellate Chytriodinium are known to infest copepod eggs causing their lethality. Despite the potential to control the population of such an ecologically important host, knowledge about Chytriodinium parasites is limited: we know little about phylogeny, parasitism, abundance, or geographical distribution. We carried out genome sequence surveys on four manually isolated sporocytes from the same sporangium, which seemed to be attached to a copepod nauplius, to analyze the phylogenetic position of Chytriodinium based on SSU and concatenated SSU/LSU rRNA gene sequences, and also characterize two genes related to the plastidial heme pathway, hemL and hemY. The results suggest the presence of a cryptic plastid in Chytriodinium and a photosynthetic ancestral state of the parasitic Chytriodinium/Dissodinium clade. Finally, by mapping Tara Oceans V9 SSU amplicon data to the recovered SSU rRNA gene sequences from the sporocytes, we show that globally, Chytriodinium parasites are most abundant within the pico/nano- and mesoplankton of the surface ocean and almost absent within microplankton, a distribution indicating that they generally exist either as free-living spores or host-associated sporangia.


Assuntos
Copépodes/parasitologia , Dinoflagellida/fisiologia , Genoma de Protozoário , Interações Hospedeiro-Parasita , Animais , Dinoflagellida/classificação , Dinoflagellida/genética , Genes de Protozoários , Genes de RNAr , Filogenia , Plastídeos/fisiologia
7.
J Eukaryot Microbiol ; 66(3): 519-524, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30080299

RESUMO

Recent surveys of marine microbial diversity have identified a previously unrecognized lineage of diplonemid protists as being among the most diverse heterotrophic eukaryotes in global oceans. Despite their monophyly (and assumed importance), they lack a formal taxonomic description, and are informally known as deep-sea pelagic diplonemids (DSPDs) or marine diplonemids. Recently, we documented morphology and molecular sequences from several DSPDs, one of which is particularly widespread and abundant in environmental sequence data. To simplify the communication of future work on this important group, here we formally propose to erect the family Eupelagonemidae to encompass this clade, as well as a formal genus and species description for the apparently most abundant phylotype, Eupelagonema oceanica, for which morphological information and single-cell amplified genome data are currently available.


Assuntos
Euglenozoários/classificação , Euglenozoários/citologia , Euglenozoários/genética , Filogenia , RNA de Protozoário/análise
8.
J Am Chem Soc ; 138(16): 5234-7, 2016 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-27052660

RESUMO

A catalytic, enantioselective γ-alkylation of α,ß-unsaturated malonates and ketoesters is reported. This strategy entails a highly regio- and enantioselective iridium-catalyzed α-alkylation of an extended enolate, and a subsequent translocation of chirality to the γ-position via a Cope rearrangement.


Assuntos
Ésteres/química , Malonatos/química , Alquilação , Compostos Alílicos/química , Catálise , Cristalografia por Raios X , Irídio , Espectroscopia de Ressonância Magnética , Estereoisomerismo
9.
J Org Chem ; 81(13): 5745-51, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27243751

RESUMO

Selective carbophilic monoaddition on N-alkynyl phthalimides was performed with organometallic reagents to afford 3-substituted N-alkynyl-3-hydroxyisoindolin-1-ones (α-hydroxy ynamides) as a new subgroup of ynamides. Owing to the alkynyl motif on the nitrogen atom, α-hydroxy ynamides were easily isomerized to the corresponding ortho-(2-oxazolyl)phenyl ketones in a CuCl-catalyzed tandem decyclization-cyclization reaction under mild conditions.

10.
Chem Pharm Bull (Tokyo) ; 64(7): 941-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27373650

RESUMO

Deacetylation of enynyl acetates under basic conditions allows convenient access to reactive allenyl ketones, which can then undergo 1,4-addition of nucleophiles to furnish ß,γ-unsaturated ketones. Benzofuran and indole derivatives have also been obtained from enynyl acetates with an o-hetero-atom-substituted aryl group via intramolecular 1,4-addition.


Assuntos
Acetatos/química , Cetonas/síntese química , Acetilação , Cetonas/química , Estrutura Molecular
11.
J Eukaryot Microbiol ; 62(4): 494-504, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25600410

RESUMO

Macrotrichomonas (Cristamonadea: Parabasalia) is an anaerobic, amitochondriate flagellate symbiont of termite hindguts. It is noteworthy for being large but not structurally complex compared with other large parabasalians, and for retaining a structure similar in appearance to the undulating membrane (UM) of small flagellates closely related to cristamonads, e.g. Tritrichomonas. Here, we have characterised the SSU rDNA from two species described as Macrotrichomonas: M. restis Kirby 1942 from Neotermes jouteli and M. lighti Connell 1932 from Paraneotermes simplicicornis. These species do not form a clade: M. lighti branches with previously characterised Macrotrichomonas sequences from Glyptotermes, while M. restis branches with the genus Metadevescovina. We examined the M. restis UM by light microscopy, scanning electron microscopy, and transmission electron microscopy, and we find common characteristics with the proximal portion of the robust recurrent flagellum of devescovinids. Altogether, we show the genus Macrotrichomonas to be polyphyletic and propose transferring M. restis to a new genus, Macrotrichomonoides. We also hypothesise that the macrotrichomonad body plan represents the ancestral state of cristamonads, from which other major forms evolved.


Assuntos
DNA de Protozoário/genética , Isópteros/parasitologia , Parabasalídeos/classificação , Parabasalídeos/genética , Animais , DNA Ribossômico/genética , Genes de RNAr , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Parabasalídeos/citologia , Filogenia , Simbiose
12.
Tetrahedron ; 71(37): 6349-6353, 2015 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-26273114

RESUMO

The palladium-catalyzed decarboxylative allylic alkylation of enol carbonates derived from lactams and ketones is described. Employing these substrates with an electronically tuned Pd catalyst system trisubstituted chiral centers are produced. These stereocenters have been previously challenging to achieve using Pd complex/chiral P-N ligand systems.

13.
J Org Chem ; 79(20): 9854-9, 2014 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-25247829

RESUMO

Bi(OTf)3-catalyzed Meyer-Schuster rearrangement of electron-rich propargyl alcohols, followed by 1,4-addition of the resulting vinyl ketone, proceeded smoothly though Meyer-Schuster rearrangement of primary propargyl alcohols is rare. This tandem reaction can be extended to an intramolecular version, featuring a one-pot dihydroquinolone synthesis.


Assuntos
Alcinos/química , Hidroquinonas/síntese química , Cetonas/química , Mesilatos/química , Propanóis/química , Compostos de Vinila/química , Catálise , Hidroquinonas/química , Estrutura Molecular
14.
Int J Urol ; 21(11): 1151-4, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24942904

RESUMO

OBJECTIVES: To analyze the reliability and validity of the Japanese version of the core lower urinary symptom score questionnaire with psychometric methods. METHOD: The present study included 140 women and 125 men who filled in a core lower urinary symptom score questionnaire while attending two lectures on lower urinary tract symptoms. Missing response rates to individual questions were 1.5-5.3%. After the descriptive analyses including box plot, Cronbach's α coefficients and Spearman's ρ were calculated for reliability and validity assessment, respectively. Factor analysis was also carried out to explore the underlying structure. RESULTS: Of the scores for 10 core symptoms, the interquartile range for pain in the bladder and urethra was 0 in both sexes, and that for stress incontinence was 0 in men. Cronbach's α of the core lower urinary symptom score was 0.733 in women and 0.721 in men. Questions regarding daytime frequency, nocturia, urgency and urgency urinary incontinence, and those on slow stream, straining and feeling of incomplete emptying were significantly correlated with each other in both sexes. Pain in the urethra and bladder showed more extensive associations in women than in men. Factor analysis showed four components in both sexes: the first was storage symptoms, second was voiding symptoms, third was pain and the fourth was urinary incontinence. CONCLUSIONS: The core lower urinary symptom score questionnaire shows good reliability and validity for both sexes, and it could be used as screening tool for lower urinary tract symptoms in any clinical setting or epidemiological investigation.


Assuntos
Sintomas do Trato Urinário Inferior/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Análise Fatorial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Inquéritos e Questionários
15.
ISME J ; 18(1)2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38457644

RESUMO

Eupelagonemids, formerly known as Deep Sea Pelagic Diplonemids I (DSPD I), are among the most abundant and diverse heterotrophic protists in the deep ocean, but little else is known about their ecology, evolution, or biology in general. Originally recognized solely as a large clade of environmental ribosomal subunit RNA gene sequences (SSU rRNA), branching with a smaller sister group DSPD II, they were postulated to be diplonemids, a poorly studied branch of Euglenozoa. Although new diplonemids have been cultivated and studied in depth in recent years, the lack of cultured eupelagonemids has limited data to a handful of light micrographs, partial SSU rRNA gene sequences, a small number of genes from single amplified genomes, and only a single formal described species, Eupelagonema oceanica. To determine exactly where this clade goes in the tree of eukaryotes and begin to address the overall absence of biological information about this apparently ecologically important group, we conducted single-cell transcriptomics from two eupelagonemid cells. A SSU rRNA gene phylogeny shows that these two cells represent distinct subclades within eupelagonemids, each different from E. oceanica. Phylogenomic analysis based on a 125-gene matrix contrasts with the findings based on ecological survey data and shows eupelagonemids branch sister to the diplonemid subgroup Hemistasiidae.


Assuntos
Euglenozoários , Eucariotos , Filogenia , Eucariotos/genética , Euglenozoários/genética , RNA Ribossômico , Oceanos e Mares
16.
J Biol Chem ; 287(13): 10631-10638, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22308029

RESUMO

Autophagy-related degradation selective for mitochondria (mitophagy) is an evolutionarily conserved process that is thought to be critical for mitochondrial quality and quantity control. In budding yeast, autophagy-related protein 32 (Atg32) is inserted into the outer membrane of mitochondria with its N- and C-terminal domains exposed to the cytosol and mitochondrial intermembrane space, respectively, and plays an essential role in mitophagy. Atg32 interacts with Atg8, a ubiquitin-like protein localized to the autophagosome, and Atg11, a scaffold protein required for selective autophagy-related pathways, although the significance of these interactions remains elusive. In addition, whether Atg32 is the sole protein necessary and sufficient for initiation of autophagosome formation has not been addressed. Here we show that the Atg32 IMS domain is dispensable for mitophagy. Notably, when anchored to peroxisomes, the Atg32 cytosol domain promoted autophagy-dependent peroxisome degradation, suggesting that Atg32 contains a module compatible for other organelle autophagy. X-ray crystallography reveals that the Atg32 Atg8 family-interacting motif peptide binds Atg8 in a conserved manner. Mutations in this binding interface impair association of Atg32 with the free form of Atg8 and mitophagy. Moreover, Atg32 variants, which do not stably interact with Atg11, are strongly defective in mitochondrial degradation. Finally, we demonstrate that Atg32 forms a complex with Atg8 and Atg11 prior to and independent of isolation membrane generation and subsequent autophagosome formation. Taken together, our data implicate Atg32 as a bipartite platform recruiting Atg8 and Atg11 to the mitochondrial surface and forming an initiator complex crucial for mitophagy.


Assuntos
Autofagia/fisiologia , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Proteínas Mitocondriais/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Família da Proteína 8 Relacionada à Autofagia , Proteínas Relacionadas à Autofagia , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Mutação , Fagossomos/genética , Fagossomos/metabolismo , Estrutura Terciária de Proteína , Receptores Citoplasmáticos e Nucleares/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
17.
Biochim Biophys Acta ; 1820(5): 595-600, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21846491

RESUMO

BACKGROUND: Mitochondria are dynamic organelles that frequently change their number, size, shape, and distribution in response to intra- and extracellular cues. After proliferated from pre-existing ones, fresh mitochondria enter constant cycles of fission and fusion that organize them into two distinct states - "individual state" and "network state". When compromised with various injuries, solitary mitochondria are subjected to organelle degradation. This clearance pathway relies on autophagy, a self-eating process that plays key roles in manifold cell activities. Recent studies reveal that defects in autophagic degradation selective for mitochondria (mitophagy) are associated with neurodegenerative diseases, highlighting the physiological relevance to cellular functions. SCOPE OF REVIEW: Here we review recent progress regarding a link between mitochondria and autophagy in yeast and multicellular eukaryotes. In particular, fundamental principles underlying mitophagy, and mitochondrial quality control are emphasized. Accumulating evidence also implicates nonselective autophagy in the management of mitochondrial fitness. Conversely, mitochondria are suggested to serve as signaling platforms vital for regulating autophagy. These interdependent relationships are likely to coordinate metabolic plasticity in the cell. MAJOR CONCLUSIONS: Mitochondria and autophagy are elaborately linked homeostatic elements that act in response to changes in cellular environment such as energy, nutrient, and stress. How cells integrate these double membrane-bound systems still remains elusive. GENERAL SIGNIFICANCE: Interplay between mitochondria and autophagy seems to be evolutionarily conserved. Defects in one of these elements could simultaneously impair the other, resulting in risk increments for various human diseases. This article is part of a Special Issue entitled Biochemistry of Mitochondria.


Assuntos
Autofagia , Mitocôndrias/patologia , Doenças Neurodegenerativas/patologia , Animais , Humanos , Transdução de Sinais
18.
Nat Commun ; 14(1): 7049, 2023 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-37923716

RESUMO

Microbial eukaryotes are important components of marine ecosystems, and the Marine Alveolates (MALVs) are consistently both abundant and diverse in global environmental sequencing surveys. MALVs are dinoflagellates that are thought to be parasites of other protists and animals, but the lack of data beyond ribosomal RNA gene sequences from all but a few described species means much of their biology and evolution remain unknown. Using single-cell transcriptomes from several MALVs and their free-living relatives, we show that MALVs evolved independently from two distinct, free-living ancestors and that their parasitism evolved in parallel. Phylogenomics shows one subgroup (MALV-II and -IV, or Syndiniales) is related to a novel lineage of free-living, eukaryovorous predators, the eleftherids, while the other (MALV-I, or Ichthyodinida) is related to the free-living predator Oxyrrhis and retains proteins targeted to a non-photosynthetic plastid. Reconstructing the evolution of photosynthesis, plastids, and parasitism in early-diverging dinoflagellates shows a number of parallels with the evolution of their apicomplexan sisters. In both groups, similar forms of parasitism evolved multiple times and photosynthesis was lost many times. By contrast, complete loss of the plastid organelle is infrequent and, when this does happen, leaves no residual genes.


Assuntos
Dinoflagellida , Parasitos , Animais , Parasitos/genética , Ecossistema , Filogenia , Plastídeos/genética , Fotossíntese/genética , Dinoflagellida/genética
19.
Proc Biol Sci ; 279(1736): 2246-54, 2012 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-22298847

RESUMO

An important missing piece in the puzzle of how plastids spread across the eukaryotic tree of life is a robust evolutionary framework for the host lineages. Four assemblages are known to harbour plastids derived from red algae and, according to the controversial chromalveolate hypothesis, these all share a common ancestry. Phylogenomic analyses have consistently shown that stramenopiles and alveolates are closely related, but haptophytes and cryptophytes remain contentious; they have been proposed to branch together with several heterotrophic groups in the newly erected Hacrobia. Here, we tested this question by producing a large expressed sequence tag dataset for the katablepharid Roombia truncata, one of the last hacrobian lineages for which genome-level data are unavailable, and combined this dataset with the recently completed genome of the cryptophyte Guillardia theta to build an alignment composed of 258 genes. Our analyses strongly support haptophytes as sister to the SAR group, possibly together with telonemids and centrohelids. We also confirmed the common origin of katablepharids and cryptophytes, but these lineages were not related to other hacrobians; instead, they branch with plants. Our study resolves the evolutionary position of haptophytes, an ecologically critical component of the oceans, and proposes a new hypothesis for the origin of cryptophytes.


Assuntos
Evolução Biológica , Criptófitas/genética , Haptófitas/fisiologia , Filogenia , Criptófitas/fisiologia , Eucariotos , Etiquetas de Sequências Expressas , Genoma , Haptófitas/genética , Plastídeos/genética
20.
J Org Chem ; 77(8): 3944-51, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22439794

RESUMO

Multisubstituted furans were readily prepared from (Z)- or (E)-conjugated enynyl acetates with NXS under metal-free conditions at room temperature via the same haloallenyl ketone intermediates. This tandem haloallenyl ketone formation-furan formation reaction sequence was accelerated by electron-donating groups on the aromatic rings.


Assuntos
Acetatos/química , Alcadienos/química , Furanos/química , Cetonas/química , Elétrons , Estrutura Molecular , Estereoisomerismo
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