RESUMO
Transposable elements exert a significant effect on the size and structure of eukaryotic genomes. Tc1/mariner superfamily elements represent the widely distributed and highly variable group of DNA transposons. Tc1/mariner elements include TLE/DD34-38E, MLE/DD34D, maT/DD37D, Visitor/DD41D, Guest/DD39D, mosquito/DD37E, and L18/DD37E families, all of which are well or less scarcely studied. However, more detailed research into the patterns of prevalence and diversity of Tc1/mariner transposons enables one to better understand the coevolution of the TEs and the eukaryotic genomes. We performed a detailed analysis of the maT/DD37D family in Cnidaria. The study of 77 genomic assemblies demonstrated that maT transposons are found in a limited number of cnidarian species belonging to classes Cubozoa (1 species), Hydrozoa (3 species) и Scyphozoa (5 species) only. The identified TEs were classified into 5 clades, with the representatives from Pelagiidae (class Scyphozoa) forming a separate clade of maT transposons, which has never been described previously. The potentially functional copies of maT transposons were identified in the hydrae. The phylogenetic analysis and the studies of distribution among the taxons and the evolutionary dynamics of the elements suggest that maT transposons of the cnidarians are the descendants of several independent invasion events occurring at different periods of time. We also established that the TEs of mosquito/DD37E family are found in Hydridae (class Hydrozoa) only. A comparison of maT and mosquito prevalence in two genomic assemblies of Hydra viridissima revealed obvious differences, thus demonstrating that each individual organism might carry a unique mobilome pattern. The results of the presented research make us better understand the diversity and evolution of Tc1/mariner transposons and their effect on the eukaryotic genomes.
Assuntos
Cnidários , Culicidae , Humanos , Animais , Culicidae/genética , Cnidários/genética , Filogenia , Elementos de DNA Transponíveis , Evolução MolecularRESUMO
The zebrafish is a promising model species in biomedical research, including neurotoxicology and neuroactive drug screening. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) evokes degeneration of dopaminergic neurons and is commonly used to model Parkinson's disease (PD) in laboratory animals, including zebrafish. However, cognitive phenotypes in MPTP-evoked experimental PD models remain poorly understood. Here, we established an LD50 (292 mg/kg) for intraperitoneal MPTP administration in adult zebrafish, and report impaired spatial working memory (poorer spontaneous alternation in the Y-maze) in a PD model utilizing fish treated with 200 µg of this agent. In addition to conventional behavioral analyses, we also employed artificial intelligence (AI)-based approaches to independently and without bias characterize MPTP effects on zebrafish behavior during the Y-maze test. These analyses yielded a distinct cluster for 200-µg MPTP (vs. other) groups, suggesting that high-dose MPTP produced distinct, computationally detectable patterns of zebrafish swimming. Collectively, these findings support MPTP treatment in adult zebrafish as a late-stage experimental PD model with overt cognitive phenotypes.
RESUMO
Transposable elements (TEs) exert a significant effect on the structure and functioning of the genomes and also serve as a source of the new genes. The study of the TE diversity and evolution in different taxa is indispensable for the fundamental understanding of their roles in the genomes. IS630/Tc1/mariner (ITm) transposable elements represent the most prevalent and diverse group of DNA transposons. In this work, we studied the diversity, evolutionary dynamics and the phylogenetic relationships of the ITm transposons found in three ctenophore species: Mnemiopsis leidyi, Pleurobrachia bachei, Beroe ovata. We identified 29 ITm transposons, seven of which possess the terminal inverted repeats (TIRs) and an intact transposase, and, thus, are, presumably, active. Four other ITm transposons have the features of domesticated TEs. According to the results of the phylogenetic analysis, the ITm transposons of the ctenophores represent five groups - MLE/DD34D, TLE/DD34-38E, mosquito/DD37E, Visiror/DD41D and pogo/DDxD. Pogo/DDxD superfamily turnes out to be the most diverse and prevalent, since it accounts for more than 40% of the TEs identified. The data obtained in this research will fill the gap of knowledge of the diversity and evolution of the ITm transposons in the multicellular genomes and will lay the ground for the study of the TE effects on the evolution of the ctenophores.
Assuntos
Ctenóforos , Culicidae , Animais , Ctenóforos/genética , Elementos de DNA Transponíveis/genética , Filogenia , Transposases/genéticaRESUMO
Due to its fully sequenced genome, high genetic homology to humans, external fertilization, fast development, transparency of embryos, low cost and active reproduction, the zebrafish (Danio rerio) has become a novel promising model organism in biomedicine. Zebrafish are a useful tool in genetic and neuroscience research, including linking various genetic mutations to brain mechanisms using forward and reverse genetics. These approaches have produced novel models of rare genetic CNS disorders and common brain illnesses, such as addiction, aggression, anxiety and depression. Genetically modified zebrafish also foster neuroanatomical studies, manipulating neural circuits and linking them to different behaviors. Here, we discuss recent advances in neurogenetics of zebrafish, and evaluate their unique strengths, inherent limitations and the rapidly growing potential for elucidating the conserved roles of genes in neuropsychiatric disorders.
Assuntos
Genética Comportamental/métodos , Neurociências/métodos , Peixe-Zebra/genética , Animais , Animais Geneticamente Modificados , Comportamento Animal , Sistemas CRISPR-Cas , Linhagem da Célula , Doenças do Sistema Nervoso Central/genética , Edição de Genes/métodos , Marcação de Genes/métodos , Modelos Animais , Locos de Características Quantitativas , RNA Bacteriano , RNA Interferente Pequeno/genética , Genética Reversa/métodos , Especificidade da Espécie , Peixe-Zebra/classificação , Proteínas de Peixe-Zebra/biossíntese , Proteínas de Peixe-Zebra/genéticaRESUMO
Herein, for the first time the complexation ability of a homological series of triphenylphosphonium surfactants (TPPB-n) toward DNA decamers has been explored. Formation of lipoplexes was confirmed by alternative techniques, including dynamic light scattering, indicating the occurrence of nanosized complexes (ca. 100-150 nm), and monitoring the charge neutralization of nucleotide phosphate groups and the fluorescence quenching of dye-intercalator ethidium bromide. The complexation efficacy of TPPB-surfactants toward an oligonucleotide (ONu) is compared with that of reference cationic surfactants. Strong effects of the alkyl chain length and the structure of the head group on the surfactant/ONu interaction are revealed, which probably occur via different mechanisms, with electrostatic and hydrophobic forces or intercalation imbedding involved. Phosphonium surfactants are shown to be capable of disordering lipid bilayers, which is supported by a decrease in the temperature of the main phase transition, Tm. This effect enhances with an increase in the alkyl chain length, indicating the integration of TPPB-n with lipid membranes. This markedly differs from the behavior of typical cationic surfactant cetyltrimethylammonium bromide, which induces an increase in the Tm value. It was demonstrated that the cytotoxicity of TPPB-n in terms of the MTT-test on a human cell line 293T nonmonotonically changes within the homological series, with the highest cytotoxicity exhibited by the dodecyl and tetradecyl homologs.
Assuntos
DNA/química , Bicamadas Lipídicas/química , Ácidos Nucleicos/química , Tensoativos/química , Membrana Celular/efeitos dos fármacos , Células HEK293 , Humanos , Tensoativos/toxicidadeRESUMO
Gemini surfactants with hexadecyl tails and hydroxyethylated head groups bridged with tetramethylene (G4), hexamethylene (G6) and dodecamethylene (G12) spacers were shown to self-assemble at the lower critical micelle concentration compared to their conventional m-s-m analogs. The lipoplex formation and the plasmid DNA transfer into different kinds of host cells were studied. In the case of eukaryotic cells, high transfection efficacy has been demonstrated for DNA-gemini complexes, which increased as follows: G6Assuntos
Técnicas de Transferência de Genes
, Compostos de Amônio Quaternário/química
, Tensoativos/química
, Transfecção/métodos
, DNA/química
, DNA/genética
, Eletroporação
, Proteínas de Fluorescência Verde/genética
, Proteínas de Fluorescência Verde/metabolismo
, Células HEK293
, Humanos
, Microscopia de Força Atômica
, Estrutura Molecular
, Conformação de Ácido Nucleico
, Plasmídeos/química
, Plasmídeos/genética
, Reprodutibilidade dos Testes
, Relação Estrutura-Atividade
, Termodinâmica