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1.
Mol Phylogenet Evol ; 195: 108057, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38471598

RESUMO

Previous efforts to reconstruct evolutionary history of Palearctic ground squirrels within the genus Spermophilus have primarily relied on a single mitochondrial marker for phylogenetic data. In this study, we present the first phylogeny with comprehensive taxon sampling of Spermophilus via a conventional multilocus approach utilizing five mitochondrial and five nuclear markers. Through application of the multispecies coalescent model, we constructed a species tree revealing four distinct clades that diverged during the Late Miocene. These clades are 1) S. alaschanicus and S. dauricus from East Asia; 2) S. musicus and S. pygmaeus from East Europe and northwestern Central Asia; 3) the subgenus Colobotis found across Central Asia and its adjacent regions and encompassing S. brevicauda, S. erythrogenys, S. fulvus, S. major, S. pallidicauda, S. ralli, S. relictus, S. selevini, and S. vorontsovi sp. nov.; and 4) a Central/Eastern Europe and Asia Minor clade comprising S. citellus, S. taurensis, S. xanthoprymnus, S. suslicus, and S. odessanus. The latter clade lacked strong support owing to uncertainty of taxonomic placement of S. odessanus and S. suslicus. Resolving relationships within the subgenus Colobotis, which radiated rapidly, remains challenging likely because of incomplete lineage sorting and introgressive hybridization. Most of modern Spermophilus species diversified during the Early-Middle Pleistocene (2.2-1.0 million years ago). We propose a revised taxonomic classification for the genus Spermophilus by recognizing 18 species including a newly identified one (S. vorontsovi sp. nov.), which is found only in a limited area in the southeast of West Siberia. Employing genome-wide single-nucleotide polymorphism genotyping, we substantiated the role of the Ob River as a major barrier ensuring robust isolation of this taxon from S. erythrogenys. Despite its inherent limitations, the traditional multilocus approach remains a valuable tool for resolving relationships and can provide important insights into otherwise poorly understood groups. It is imperative to recognize that additional efforts are needed to definitively determine phylogenetic relationships between certain species of Palearctic ground squirrels.


Assuntos
Introgressão Genética , Sciuridae , Animais , Sibéria , Filogenia , Sciuridae/genética , Ásia
2.
Biol Direct ; 18(1): 45, 2023 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-37568147

RESUMO

BACKGROUND: It is generally accepted that most evolutionary transformations at the phenotype level are associated either with rearrangements of genomic regulatory elements, which control the activity of gene networks, or with changes in the amino acid contents of proteins. Recently, evidence has accumulated that significant evolutionary transformations could also be associated with the loss/emergence of whole genes. The targeted identification of such genes is a challenging problem for both bioinformatics and evo-devo research. RESULTS: To solve this problem we propose the WINEGRET method, named after the first letters of the title. Its main idea is to search for genes that satisfy two requirements: first, the desired genes were lost/emerged at the same evolutionary stage at which the phenotypic trait of interest was lost/emerged, and second, the expression of these genes changes significantly during the development of the trait of interest in the model organism. To verify the first requirement, we do not use existing databases of orthologs, but rely purely on gene homology and local synteny by using some novel quickly computable conditions. Genes satisfying the second requirement are found by deep RNA sequencing. As a proof of principle, we used our method to find genes absent in extant amniotes (reptiles, birds, mammals) but present in anamniotes (fish and amphibians), in which these genes are involved in the regeneration of large body appendages. As a result, 57 genes were identified. For three of them, c-c motif chemokine 4, eotaxin-like, and a previously unknown gene called here sod4, essential roles for tail regeneration were demonstrated. Noteworthy, we established that the latter gene belongs to a novel family of Cu/Zn-superoxide dismutases lost by amniotes, SOD4. CONCLUSIONS: We present a method for targeted identification of genes whose loss/emergence in evolution could be associated with the loss/emergence of a phenotypic trait of interest. In a proof-of-principle study, we identified genes absent in amniotes that participate in body appendage regeneration in anamniotes. Our method provides a wide range of opportunities for studying the relationship between the loss/emergence of phenotypic traits and the loss/emergence of specific genes in evolution.


Assuntos
Mamíferos , Animais
3.
Int J Mol Sci ; 24(13)2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37445647

RESUMO

We explored the relationship between the copy number of mitochondrial DNA (mtDNA-CN) and all-cause natural mortality. We examined a random population sample in 2003/2005 (n = 9360, men/women, 45-69, the HAPIEE project) and followed up for 15 years. Using a nested case-control design, we selected non-external deaths among those free from baseline cardiovascular diseases (CVD) and cancer (n = 371), and a sex- and age-stratified control (n = 785). The odds ratios (ORs) of death were 1.06 (95%CI 1.01-1.11) per one-decile decrease in mtDNA-CN independent of age, sex, metabolic factors, smoking, alcohol intake and education. The age-sex-adjusted ORs of death in the second and first tertiles of mtDNA-CN vs. the top tertile were 2.35 (95% CI 1.70-3.26) and 1.59 (1.16-2.17); an increased risk was confined to the second tertile after controlling for smoking and metabolic factors. The multivariable-adjusted OR of CVD death was 1.92 (95% CI 1.18-3.15) in tertile 2 vs. the top tertile of mtDNA-CN, and for cancer-related death the ORs were 3.66 (95% CI 2.21-6.05) and 2.29 (95% CI 1.43-3.68) in tertiles 2 and 1 vs. the top tertile. In the Siberian population cohort, the mtDNA-CN was an inverse predictor of the 15-year risk of natural mortality, due to the greatest impact of CVD and cancer-related death. The findings merit attention for exploring further the role of mtDNA in human ageing and the diversity of mortality.


Assuntos
Doenças Cardiovasculares , DNA Mitocondrial , Masculino , Humanos , Feminino , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Seguimentos , Variações do Número de Cópias de DNA , Fatores de Risco , Estudos Prospectivos , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/epidemiologia
4.
Biodivers Data J ; 11: e115477, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38161489

RESUMO

Staphylinidae, or rove beetles, are one of the mega-diverse and abundant families of the ground-living terrestrial arthropods that is taxonomically poorly known even in the regions adjacent to Europe where the fauna has been investigated for the longest time. Since DNA barcoding is a tool to accelerate biodiversity research, here we explored if the currently-available COI barcode libraries are representative enough for the study of rove beetles of West Siberia. This is a vast region adjacent to Europe with poorly-known fauna of rove beetles and from where not a single DNA barcode has hitherto been produced for Staphylinidae. First, we investigated the faunal similarity between the rove beetle faunas of the climatically compatible West Siberia in Asia, Fennoscandia in Europe and Canada and Alaska in North America. Second, we investigated barcodes available for Staphylinidae from the latter two regions in BOLD and GenBank, the world's largest DNA barcode libraries. We conclude that the rather different rove beetle faunas of Fennoscandia, on the one hand and Canada and Alaska on the other hand, are well covered in both barcode libraries that complement each other. We also find that even without any barcodes originating from specimens collected in West Siberia, this coverage is helpful for the study of rove beetles there due to the significant number of widespread species shared between West Siberia and Fennoscandia and due to the even larger number of shared genera amongst all three investigated regions. For the first time, we compiled a literature-based checklist for 726 species of the West Siberian Staphylinidae supplemented by their occurrence dataset submitted to GBIF. Our script written for mining unique (i.e. not redundant) barcodes for a given geographic area across global libraries is made available here and can be adopted for any other regions.

5.
Folia Microbiol (Praha) ; 67(4): 591-604, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35318574

RESUMO

One of the most frequently used methods for elimination of oil pollution is the use of biological preparations based on oil-degrading microorganisms. Such microorganisms often relate to bacteria of the genus Pseudomonas. Pseudomonads are ubiquitous microorganisms that often have the ability to oxidize various pollutants, including oil hydrocarbons. To date, individual biochemical pathways of hydrocarbon degradation and the organization of the corresponding genes have been studied in detail. Almost all studies of this kind have been performed on degraders of individual hydrocarbons belonging to a single particular class. Microorganisms capable of simultaneous degradation of aliphatic and aromatic hydrocarbons are very poorly studied. Most of the works on such objects have been devoted only to phenotype characteristic and some to genetic studies. To identify the patterns of interaction of several metabolic systems depending on the growth conditions, the most promising are such approaches as transcriptomics and proteomics, which make it possible to obtain a comprehensive assessment of changes in the expression of hundreds of genes and proteins at the same time. This review summarizes the existing data on bacteria of the genus Pseudomonas capable of the simultaneous oxidation of hydrocarbons of different classes (alkanes, monoaromatics, and polyaromatics) and presents the most important results obtained in the studies on the biodegradation of hydrocarbons by representatives of this genus using methods of transcriptomic and proteomic analyses.


Assuntos
Hidrocarbonetos Aromáticos , Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Bactérias , Biodegradação Ambiental , Hidrocarbonetos/metabolismo , Hidrocarbonetos Aromáticos/metabolismo , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Proteômica , Pseudomonas/genética , Pseudomonas/metabolismo
6.
Pharmaceutics ; 14(1)2022 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-35057100

RESUMO

A new hydrophilic polymeric nanocomposite containing AgNPs was synthesized by chemical reduction of metal ions in an aqueous medium in the presence of the copolymer. A new water-soluble copolymer of 1-vinyl-1,2,4-triazole and vinylsulfonic acid sodium salt (poly(VT-co-Na-VSA)) was obtained by free-radical copolymerization and was used as a stabilizing precursor agent. The structural, dimensional, and morphological properties of the nanocomposite were studied by UV-Vis, FTIR, X-ray diffraction, atomic absorption, transmission and scanning electron microscopy, dynamic and electrophoretic light scattering, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry. Hydrodynamic diameter of macroclubs for the copolymer was 171 nm, and for the nanocomposite it was 694 nm. Zeta potential for the copolymer was -63.8 mV, and for the nanocomposite it was -70.4 mV. The nanocomposite had strong antimicrobial activity towards Gram-negative and Gram-positive microorganisms: MIC and MBC values were in the range of 0.25-4.0 and 0.5-8.0 µg/mL, respectively.

7.
Front Cell Dev Biol ; 9: 738940, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34676214

RESUMO

Warm-blooded vertebrates regenerate lost limbs and their parts in general much worse than fishes and amphibians. We previously hypothesized that this reduction in regenerative capability could be explained in part by the loss of some genes important for the regeneration in ancestors of warm-blooded vertebrates. One of such genes could be ag1, which encodes secreted protein disulfide isomerase of the Agr family. Ag1 is activated during limb and tail regeneration in the frog Xenopus laevis tadpoles and is absent in warm-blooded animals. The essential role of another agr family gene, agr2, in limb regeneration was demonstrated previously in newts. However, agr2, as well as the third member of agr family, agr3, are present in all vertebrates. Therefore, it is important to verify if the activity of ag1 lost by warm-blooded vertebrates is also essential for regeneration in amphibians, which could be a further argument in favor of our hypothesis. Here, we show that in the Xenopus laevis tadpoles in which the expression of ag1 or agr2 was artificially suppressed, regeneration of amputated tail tips was also significantly reduced. Importantly, overexpression of any of these agrs or treatment of tadpoles with any of their recombinant proteins resulted in the restoration of tail regeneration in the refractory period when these processes are severely inhibited in normal development. These findings demonstrate the critical roles of ag1 and agr2 in regeneration in frogs and present indirect evidence that the loss of ag1 in evolution could be one of the prerequisites for the reduction of regenerative ability in warm-blooded vertebrates.

8.
Molecules ; 26(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203966

RESUMO

Nanoparticle-reinforced polymer-based materials effectively combine the functional properties of polymers and unique characteristic features of NPs. Biopolymers have attained great attention, with perspective multifunctional and high-performance nanocomposites exhibiting a low environmental impact with unique properties, being abundantly available, renewable, and eco-friendly. Nanocomposites of biopolymers are termed green biocomposites. Different biocomposites are reported with numerous inorganic nanofillers, which include selenium. Selenium is a micronutrient that can potentially be used in the prevention and treatment of diseases and has been extensively studied for its biological activity. SeNPs have attracted increasing attention due to their high bioavailability, low toxicity, and novel therapeutic properties. One of the best routes to take advantage of SeNPs' properties is by mixing these NPs with polymers to obtain nanocomposites with functionalities associated with the NPs together with the main characteristics of the polymer matrix. These nanocomposite materials have markedly improved properties achieved at low SeNP concentrations. Composites based on polysaccharides, including fungal beta-glucans, are bioactive, biocompatible, biodegradable, and have exhibited an innovative potential. Mushrooms meet certain obvious requirements for the green entity applied to the SeNP manufacturing. Fungal-matrixed selenium nanoparticles are a new promising biocomposite material. This review aims to give a summary of what is known by now about the mycosynthesized selenium polymeric nanocomposites with the impact on fungal-assisted manufactured ones, the mechanisms of the involved processes at the chemical reaction level, and problems and challenges posed in this area.


Assuntos
Biopolímeros/química , Nanopartículas Metálicas/química , Selênio/química , Materiais Biocompatíveis/química , Disponibilidade Biológica , Fungos , Nanocompostos/química , Nanopartículas/química , Selênio/metabolismo
9.
Int J Mol Sci ; 21(12)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580466

RESUMO

Multipotent stromal cells (MSC) demonstrate remarkable functional heterogeneity; however, its molecular mechanisms remain largely obscure. In this study, we explored MSC response to hormones, which activate Gs-protein / cyclic AMP (cAMP) / protein kinase A (PKA) dependent signaling, at the single cell level using genetically encoded biosensor PKA-Spark. For the first time, we demonstrated that about half of cultured MSCs are not able to activate the cAMP/PKA pathway, possibly due to the limited availability of adenylyl cyclases. Using this approach, we showed that MSC subpopulations responding to various hormones largely overlapped, and the share of responding cells did not exceed 40%. Using clonal analysis, we showed that signaling heterogeneity of MSC could be formed de novo within 2 weeks.


Assuntos
Adenilil Ciclases/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/classificação , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hormônios/farmacologia , Células-Tronco Mesenquimais/metabolismo , Adenilil Ciclases/genética , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/genética , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Transdução de Sinais
10.
Genesis ; 57(5): e23293, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30912273

RESUMO

The Agr family genes, Ag1, Agr2, and Agr3, encode for the thioredoxin domain containing secreted proteins and are specific only for vertebrates. These proteins are attracting increasing attention due to their involvement in many physiological and pathological processes, including exocrine secretion, cancer, regeneration of the body appendages, and the early brain development. At the same time, the mode by which Agrs regulate intracellular processes are poorly understood. Despite that the receptor to Agr2, the membrane anchored protein Prod1, has been firstly discovered in Urodeles, and it has been shown to interact with Agr2 in the regenerating limb, no functional homologs of Prod1 were identified in other vertebrates. This raises the question of the mechanisms by which Agrs can regulate regeneration in other lower vertebrates. Recently, we have identified that Tfp4 (three-fingers Protein 4), the structural and functional homolog of Prod1 in Anurans, interacts with Agr2 in Xenopus laevis embryos. In the present work we show by several methods that the activity of Tfp4 is essential for the tadpole tail regeneration as well as for the early eye and forebrain development during embryogenesis. These data show for the first time the common molecular mechanism of regeneration regulation in amphibians by interaction of Prod1 and Agr2 proteins.


Assuntos
Arginase/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Regeneração/fisiologia , Proteínas de Xenopus/metabolismo , Animais , Proteínas de Transporte/metabolismo , Desenvolvimento Embrionário , Extremidades/embriologia , Larva/genética , Larva/metabolismo , Organogênese , Ligação Proteica/fisiologia , Regeneração/genética , Tiorredoxinas/metabolismo , Proteínas de Xenopus/genética , Xenopus laevis/metabolismo
11.
Int J Mol Sci ; 19(12)2018 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-30469522

RESUMO

Primary adipose tissue-derived multipotent stem/stromal cells (adMSCs) demonstrate unusual signaling regulatory mechanisms, i.e., increased of sensitivity to catecholamines in response to noradrenaline. This phenomenon is called "heterologous sensitization", and was previously found only in embryonic cells. Since further elucidation of the molecular mechanisms that are responsible for such sensitization in primary adMSCs was difficult due to the high heterogeneity in adrenergic receptor expression, we employed immortalized adipose-derived mesenchymal stem cell lines (hTERT-MSCs). Using flow cytometry and immunofluorescence microscopy, we demonstrated that the proportion of cells expressing adrenergic receptor isoforms does not differ significantly in hTERT-MSCs cells compared to the primary adMSCs culture. However, using analysis of Ca2+-mobilization in single cells, we found that these cells did not demonstrate the sensitization seen in primary adMSCs. Consistently, these cells did not activate cAMP synthesis in response to noradrenaline. These data indicate that immortalized adipose-derived mesenchymal stem cell lines demonstrated impaired ability to respond to noradrenaline compared to primary adMSCs. These data draw attention to the usage of immortalized cells for MSCs-based regenerative medicine, especially in the field of pharmacology.


Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Norepinefrina/farmacologia , Tecido Adiposo/citologia , Sinalização do Cálcio , Linhagem Celular , Células Cultivadas , AMP Cíclico/metabolismo , Humanos , Células-Tronco Mesenquimais/metabolismo
12.
Sci Rep ; 8(1): 13035, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30158598

RESUMO

In contrast to amniotes (reptiles, birds and mammals), anamniotes (fishes and amphibians) can effectively regenerate body appendages such as fins, limbs and tails. Why such a useful capability was progressively lost in amniotes remains unknown. As we have hypothesized recently, one of the reasons for this could be loss of some genes regulating the regeneration in evolution of amniotes. Here, we demonstrate the validity of this hypothesis by showing that genes of small GTPases Ras-dva1 and Ras-dva2, that had been lost in a stepwise manner during evolution of amniotes and disappeared completely in placental mammals, are important for regeneration in anamniotes. Both Ras-dva genes are quickly activated in regenerative wound epithelium and blastema forming in the amputated adult Danio rerio fins and Xenopus laevis tadpoles' tails and hindlimb buds. Down-regulation of any of two Ras-dva genes in fish and frog resulted in a retardation of regeneration accompanied by down-regulation of the regeneration marker genes. On the other hand, Ras-dva over-expression in tadpoles' tails restores regeneration capacity during the refractory period when regeneration is blocked due to natural reasons. Thus our data on Ras-dva genes, which were eliminated in amniotes but play role in anamniotes regeneration regulation, satisfy our hypothesis.


Assuntos
Evolução Molecular , Regulação da Expressão Gênica , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Regeneração , Animais , Xenopus laevis , Peixe-Zebra
13.
Indian Heart J ; 69 Suppl 1: S8-S11, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28400043

RESUMO

OBJECTIVE: Investigate the association of rs17465637 gene MIAF3 (1q41), rs1376251 gene TAS2R50 (12p13), rs4804611 gene ZNF627 (19p13), rs619203 gene ROS1 (6q22), rs1333049 (9p21), rs10757278 (9p21), rs2549513 (16q23), rs499818 (6p24) associated with myocardial infarction available from the international genome-wide studies with sudden cardiac death (SCD) in a case-control study. METHODS: A sample of SCD cases (n=285) was formed using the WHO criteria; the control sample (n=421) was selected according to sex and age. DNA was isolated by phenol-chloroform extraction from the myocardial tissue of SCD cases and blood of control cases. The groups were genotyped for the selected SNPs by real-time PCR using TaqMan probes (Applied Biosystems, United States). RESULTS: No statistically significant differences in the genotype and allelic frequencies of studied single nucleotide polymorphisms between sudden cardiac death cases and control were detectable in general group. By separating the groups of sex and age differences in the genotype frequencies of rs1333049, rs10757278 and rs499818 are statistical significance. Genotypes CC of rs1333049 and GG of rs10757278 are associated with an increased sudden cardiac death risk in men (p=0.019, OR=1.7, 95% CI 1.1-2.8; p=0.011, OR=1.8, 95% CI 1.2-2.8, respectively). Genotype AG of rs499818 is associated with an increased sudden cardiac death risk in the women over 50 years old (p=0.009, OR=2.4, 95% CI 1.3-4.6). CONCLUSION: Polymorphisms rs1333049 and rs10757278 are associated with SCD in men and rs499818 in the women aged over 50 years.


Assuntos
DNA/genética , Morte Súbita Cardíaca/etiologia , Estudo de Associação Genômica Ampla/métodos , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Medição de Risco , Morte Súbita Cardíaca/epidemiologia , Feminino , Marcadores Genéticos , Predisposição Genética para Doença , Genótipo , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Infarto do Miocárdio/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Fatores de Risco , Federação Russa/epidemiologia , Taxa de Sobrevida/tendências
14.
Sci Rep ; 5: 8123, 2015 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-25630240

RESUMO

Agr family includes three groups of genes, Ag1, Agr2 and Agr3, which encode the thioredoxin domain-containing secreted proteins and have been shown recently to participate in regeneration of the amputated body appendages in amphibians. By contrast, higher vertebrates have only Agr2 and Agr3, but lack Ag1, and have low ability to regenerate the body appendages. Thus, one may hypothesize that loss of Ag1 in evolution could be an important event that led to a decline of the regenerative capacity in higher vertebrates. To test this, we have studied now the expression and role of Ag1 in the regeneration of fins of a representative of another large group of lower vertebrates, the fish Danio rerio. As a result, we have demonstrated that amputation of the Danio fins, like amputation of the body appendages in amphibians, elicits an increase of Ag1 expression in cells of the stump. Furthermore, down-regulation of DAg1 by injections of Vivo-morpholino antisense oligonucleotides resulted in a retardation of the fin regeneration. These data are in a good agreement with the assumption that the loss of Ag1 in higher vertebrates ancestors could lead to the reduction of the regenerative capacity in their modern descendants.


Assuntos
Nadadeiras de Animais/fisiologia , Isomerases de Dissulfetos de Proteínas/metabolismo , Regeneração , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Apoptose/efeitos dos fármacos , DNA Complementar/genética , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Hibridização In Situ , Marcação In Situ das Extremidades Cortadas , Injeções , Morfolinos/administração & dosagem , Morfolinos/farmacologia , Reação em Cadeia da Polimerase , Biossíntese de Proteínas , Isomerases de Dissulfetos de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regeneração/genética , Fatores de Tempo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
15.
Biol Open ; 3(3): 192-203, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24570397

RESUMO

We previously found that the small GTPase Ras-dva1 is essential for the telencephalic development in Xenopus laevis because Ras-dva1 controls the Fgf8-mediated induction of FoxG1 expression, a key telencephalic regulator. In this report, we show, however, that Ras-dva1 and FoxG1 are expressed in different groups of cells; whereas Ras-dva1 is expressed in the outer layer of the anterior neural fold, FoxG1 and Fgf8 are activated in the inner layer from which the telencephalon is derived. We resolve this paradox by demonstrating that Ras-dva1 is involved in the transduction of Fgf8 signal received by cells in the outer layer, which in turn send a feedback signal that stimulates FoxG1 expression in the inner layer. We show that this feedback signal is transmitted by secreted Agr proteins, the expression of which is activated in the outer layer by mediation of Ras-dva1 and the homeodomain transcription factor Otx2. In turn, Agrs are essential for maintaining Fgf8 and FoxG1 expression in cells at the anterior neural plate border. Our finding reveals a novel feedback loop mechanism based on the exchange of Fgf8 and Agr signaling between neural and non-neural compartments at the anterior margin of the neural plate and demonstrates a key role of Ras-dva1 in this mechanism.

16.
Sci Rep ; 3: 1279, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23412115

RESUMO

Previous studies have shown that Agr genes, which encode thioredoxin domain-containing secreted proteins, play a critical role in limb regeneration in salamanders. To determine the evolutionary conservation of Agr function, it is important to examine whether Agrs play a similar role in species with a different type of regeneration. Here, we refined the phylogeny of Agrs, revealing three subfamilies: Ag1, Agr2 and Agr3. Importantly, we established that Ag1 was lost in higher vertebrates, which correlates with their decreased regeneration ability. In Xenopus laevis tadpoles (anamniotes), which have all three Agr subfamilies and a high regenerating capacity, Agrs were activated in the stumps of tails and hindlimb buds that were amputated at stage 52. However, Agrs were not up-regulated when the hindlimb buds were amputated at stage 57, the stage at which their regeneration capacity is lost. Our findings indicate the general importance of Agrs for body appendages regeneration in amphibians.


Assuntos
Regeneração/genética , Proteínas de Xenopus/genética , Animais , Genes , Membro Posterior/fisiologia , Larva , Filogenia , Isomerases de Dissulfetos de Proteínas/genética , Isomerases de Dissulfetos de Proteínas/fisiologia , Proteínas de Xenopus/fisiologia , Xenopus laevis
17.
J Org Chem ; 77(13): 5770-4, 2012 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-22734883

RESUMO

A series of hitherto unknown hetaryl-substituted (in phosphonium part) phosphonium-iodonium ylides were synthesized. The reaction of these mixed phosphonium-iodonium ylides with acetylenes opens a way to new furyl annelated phosphinolines or unusually substituted phosphininofurans.


Assuntos
Furanos/síntese química , Compostos Heterocíclicos/síntese química , Hidrocarbonetos Iodados/síntese química , Compostos Organofosforados/síntese química , Furanos/química , Compostos Heterocíclicos/química , Hidrocarbonetos Iodados/química , Estrutura Molecular , Compostos Organofosforados/química
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