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1.
Multivariate Behav Res ; 58(2): 441-465, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35001769

RESUMO

Analytical methods derived from nonlinear dynamical systems, complexity, and chaos theories offer researchers a framework for in-depth analysis of time series data. However, relatively few studies involving time series data obtained from psychological and behavioral research employ such methods. This paucity of application is due to a lack of general analysis frameworks for modeling time series data with strong nonlinear components. In this article, we describe the potential of Hankel alternative view of Koopman (HAVOK) analysis for solving this issue. HAVOK analysis is a unified framework for nonlinear dynamical systems analysis of time series data. By utilizing HAVOK analysis, researchers may model nonlinear time series data in a linear framework while simultaneously reconstructing attractor manifolds and obtaining a secondary time series representing the amount of nonlinear forcing occurring in a system at any given time. We begin by showing the mathematical underpinnings of HAVOK analysis and then show example applications of HAVOK analysis for modeling time series data derived from real psychological and behavioral studies.


Assuntos
Dinâmica não Linear , Fatores de Tempo , Matemática
2.
BMC Genomics ; 22(1): 505, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34225652

RESUMO

BACKGROUND: Sunflower is an important oilseed crop domesticated in North America approximately 4000 years ago. During the last century, oil content in sunflower was under strong selection. Further improvement of oil properties achieved by modulating its fatty acid composition is one of the main directions in modern oilseed crop breeding. RESULTS: We searched for the genetic basis of fatty acid content variation by genotyping 601 inbred sunflower lines and assessing their lipid and fatty acid composition. Our genome-wide association analysis based on the genotypes for 15,483 SNPs and the concentrations of 23 fatty acids, including minor fatty acids, revealed significant genetic associations for eleven of them. Identified genomic regions included the loci involved in rare fatty acids variation on chromosomes 3 and 14, explaining up to 34.5% of the total variation of docosanoic acid (22:0) in sunflower oil. CONCLUSIONS: This is the first large scale implementation of high-throughput lipidomic profiling to sunflower germplasm characterization. This study contributes to the genetic characterization of Russian sunflower collections, which made a substantial contribution to the development of sunflower as the oilseed crop worldwide, and provides new insights into the genetic control of oil composition that can be implemented in future studies.


Assuntos
Ácidos Graxos/análise , Helianthus , Óleos de Plantas/análise , Estudos de Associação Genética , Genótipo , Helianthus/genética , América do Norte , Melhoramento Vegetal , Federação Russa
3.
Chromosoma ; 129(3-4): 275-283, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33123817

RESUMO

Darevskia rostombekowi, the most outstanding of the seven known parthenogenetic species in the genus Darevskia, is the result of an ancestral cross between two bisexual species Darevskia raddei and Darevskia portschinskii. The chromosomal set of this species includes a unique submetacentric autosomal chromosome; the origin of this chromosome was unresolved as only acrocentric chromosomes are described in the karyotypes of Darevskia genus normally. Here, we applied a suite of molecular cytogenetic techniques, including the mapping of telomeric (TTAGGG) n repeats using fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and whole-chromosome painting (WCP) in both D. rostombekowi and parental (D. portschinskii and D. raddei) species. The obtained results in total suggest that a de novo chromosomal rearrangement via Robertsonian translocation (centric fusion) between two maternal (D. raddei) acrocentric chromosomes of different size was involved in the formation of this unique submetacentric chromosome present in the parthenogenetic species D. rostombekowi. Our findings provide new data in specific and rapid evolutional processes of a unisexual reptile species karyotype.


Assuntos
Evolução Molecular , Hibridização Genética , Cariótipo , Lagartos/genética , Partenogênese/genética , Translocação Genética , Animais , Mapeamento Cromossômico , Hibridização Genômica Comparativa , Feminino , Hibridização in Situ Fluorescente , Herança Materna , Cromossomos Sexuais , Telômero
4.
Mol Reprod Dev ; 88(2): 119-127, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33438277

RESUMO

Parthenogenetic species of Caucasian rock lizards of the genus Darevksia are important evidence for reticulate evolution and speciation by hybridization in vertebrates. Female-only lineages formed through interspecific hybridization have been discovered in many groups. Nevertheless, critical mechanisms of oogenesis and specifics of meiosis that provide long-term stability of parthenogenetic species are still unknown. Here we report cytogenetic characteristics of somatic karyotypes and meiotic prophase I nuclei in the diploid parthenogenetic species Darevskia unisexualis from the new population "Keti" in Armenia which contains an odd number of chromosomes 2n = 37, instead of the usual 2n = 38. We revealed 36 acrocentric chromosomes and a single metacentric autosomal chromosome, resulting from Robertsonian translocation. Comparative genomic hybridization revealed that chromosome fusion occurred between two chromosomes inherited from the maternal species, similar to another parthenogenetic species D. rostombekowi. To trace the chromosome behaviour in meiosis, we performed an immunocytochemical study of primary oocytes' spread nuclei and studied chromosome synapsis during meiotic prophase I in D. unisexualis based on analysis of synaptonemal complexes (SCs). We found meiotic SC-trivalent composed of one metacentric and two acrocentric chromosomes. We confirmed that the SC was assembled between homeologous chromosomes inherited from two parental species. Immunostaining of the pachytene and diplotene nuclei revealed a mismatch repair protein MLH1 loaded to all autosomal SC bivalents. Possible mechanisms of meiotic recombination between homeologous chromosomes are discussed.


Assuntos
Lagartos/genética , Prófase Meiótica I/genética , Proteína 1 Homóloga a MutL/genética , Animais , Células Cultivadas , Reparo de Erro de Pareamento de DNA , Rearranjo Gênico , Lagartos/fisiologia , Partenogênese , Complexo Sinaptonêmico
5.
Dev Dyn ; 247(11): 1186-1198, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30295986

RESUMO

BACKGROUND: The tissue-specific transcriptional programs during normal development require tight control by distal cis-regulatory elements, such as enhancers, with specific DNA sequences recognized by transcription factors, coactivators, and chromatin remodeling enzymes. Gata3 is a sequence-specific DNA-binding transcription factor that regulates formation of multiple tissues and organs, including inner ear, lens, mammary gland, T-cells, urogenital system, and thyroid gland. In the eye, Gata3 has a highly restricted expression domain in the posterior part of the lens vesicle; however, the underlying regulatory mechanisms are unknown. RESULTS: Here we describe the identification of a novel bipartite Gata3 lens-specific enhancer located ∼18 kb upstream from its transcriptional start site. We also found that a 5-kb Gata3 promoter possesses low activity in the lens. The bipartite enhancer contains arrays of AP-1, Ets-, and Smad1/5-binding sites as well as binding sites for lens-associated DNA-binding factors. Transient transfection studies of the promoter with the bipartite enhancer showed enhanced activation by BMP4 and FGF2. CONCLUSIONS: These studies identify a novel distal enhancer of Gata3 with high activity in lens and indicate that BMP and FGF signaling can up-regulate expression of Gata3 in differentiating lens fiber cells through the identified Gata3 enhancer and promoter elements. Developmental Dynamics 247:1186-1198, 2018. © 2018 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.


Assuntos
Elementos Facilitadores Genéticos , Fator de Transcrição GATA3/genética , Cristalino/embriologia , Animais , Sítios de Ligação , Proteína Morfogenética Óssea 4/fisiologia , Proteínas de Ligação a DNA , Fator 2 de Crescimento de Fibroblastos/fisiologia , Fator de Transcrição GATA3/química , Fator de Transcrição GATA3/metabolismo , Camundongos , Regiões Promotoras Genéticas , Ativação Transcricional
6.
Medicina (Kaunas) ; 55(6)2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31163661

RESUMO

Background and objectives: Diagnostic delay causes unfavorable outcomes among cancer patients. It has been widely analyzed in solid tumors. However, data regarding hematological malignancies diagnostic delay are scarce. We aimed to evaluate diagnostic intervals, their influencing factors, and the negative effect on clinical outcomes among multiple myeloma and lymphoma patients. Materials and methods: One hundred patients diagnosed with multiple myeloma (n = 53) or lymphoma (n = 47) (ICD codes-C90, C81-C84) were asked to participate during their scheduled hematology consultations. Interval durations and the majority of influencing factors were assessed based on a face-to-face questionnaire. Data of disease characteristics were collected from medical records. Results: The median interval from symptom onset to registration for medical consultation was 30 (0-730) days, from registration to consultation 2 (0-30) days, from first consultation to diagnosis 73 (6-1779) days, and from diagnosis to treatment 5 (0-97) days. Overall time to diagnosis median was 151 (23-1800) days. Factors significantly prolonging diagnostic intervals in multivariate linear regression were living in big cities (p = 0.008), anxiety and depression (p = 0.002), self-medication (p = 0.019), and more specialists seen before diagnosis (p = 0.022). Longer diagnostic intervals resulted in higher incidences of multiple myeloma complications (p = 0.024) and more advanced Durie-Salmon stage (p = 0.049), but not ISS stage and Ann-Arbor staging systems for lymphomas. Conclusion: Median overall diagnostic delay was nearly 5 months, indicating that there is room for improvement. The most important factors causing delays were living in big cities, anxiety and depression, self-medication, and more specialists seen before diagnosis. Diagnostic delay may have a negative influence on clinical outcomes for multiple myeloma patients.


Assuntos
Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/terapia , Fatores de Tempo , Idoso , Diagnóstico Tardio/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Inquéritos e Questionários
8.
Arch Virol ; 161(1): 63-75, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26475154

RESUMO

Densoviruses are a group of arthropod-infecting viruses with a small single-stranded linear DNA genome. These viruses constitute the subfamily Densovirinae of the family Parvoviridae. While recombination in between vertebrate-infecting parvoviruses has been investigated, to date, no systematic analysis of recombination has been carried out for densoviruses. The aim of the present work was to study possible recombination events in the evolutionary history of densoviruses and to assess possible effects of recombination on phylogenies inferred using amino acid sequences of nonstructural (NS) and capsid (viral protein, VP) proteins. For this purpose, the complete or nearly complete genome nucleotide sequences of 40 densoviruses from the GenBank database were used to construct a phylogenetic cladogram. The viruses under study clustered into five distinct groups corresponding to the five currently accepted genera. Recombination within each group was studied independently. The RDP4 software revealed three statistically highly credible recombination events, two of which involved viruses of the genus Ambidensovirus, and the other, viruses from the genus Iteradensovirus. These recombination events led to mismatches between phylogenetic trees constructed using comparison of amino acid sequences of proteins encoded by genome regions of recombinant and non-recombinant origin (regulatory NS1 and NS3 proteins and capsid VP protein).


Assuntos
Densovirus/classificação , Densovirus/genética , Filogenia , Recombinação Genética , Densovirus/isolamento & purificação , Evolução Molecular , Fases de Leitura Aberta , Proteínas Virais/genética
9.
Res Sq ; 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37163047

RESUMO

Trump supporting Twitter posting activity from right-wing Russian trolls active during the 2016 United States presidential election was analyzed at multiple timescales using a recently developed procedure for separating linear and nonlinear components of time series. Trump supporting topics were extracted with DynEGA (Dynamic Exploratory Graph Analysis) and analyzed with Hankel Alternative View of Koopman (HAVOK) procedure. HAVOK is an exploratory and predictive technique that extracts a linear model for the time series and a corresponding nonlinear time series that is used as a forcing term for the linear model. Together, this forced linear model can produce surprisingly accurate reconstructions of nonlinear and chaotic dynamics. Using the R package havok, Russian troll data yielded well-fitting models at several timescales, not producing well-fitting models at others, suggesting that only a few timescales were important for representing the dynamics of the troll factory. We identified system features that were timescale-universal versus timescale-specific. Timescale-universal features included cycles inherent to troll factory governance, which identified their work-day and work-week organization, later confirmed from published insider interviews. Cycles were captured by eigen-vector basis components resembling Fourier modes, rather than Legendre polynomials typical for HAVOK. This may be interpreted as the troll factory having intrinsic dynamics that are highly coupled to nearly stationary cycles. Forcing terms were timescale-specific. They represented external events that precipitated major changes in the time series and aligned with major events during the political campaign. HAVOK models specified interactions between the discovered components allowing to reverse-engineer the operation of Russian troll factory. Steps and decision points in the HAVOK analysis are presented and the results are described in detail.

10.
PLoS One ; 18(10): e0288772, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37792750

RESUMO

Oleic acid is a monounsaturated fatty acid increasing oil oxidative stability. High content of oleic acid is thus a valuable trait in oilseed crops. Sunflower (Helianthus annuus L.) normally accumulates linoleic acid as a major fatty acid, but a mutant expressing a high oleic phenotype form was previously obtained by chemical mutagenesis and mapped on the sunflower genome. Several studies suggest the presence of additional genes involved in the control of the high content of oleic acid, with their expression possibly depending on the genetic background. To test this hypothesis, we performed a QTL mapping of the high oleic acid trait within two independent F2 crosses involving lines with contrasting oleic acid content from the Pustovoit All-Russia Research Institute of Oil Crops (VNIIMK) collection. We applied genotyping-by-sequencing (GBS) to construct single nucleotide polymorphism-based genetic maps and performed QTL mapping using quantitative and qualitative encoding for oleic acid content. Our results support the finding that the oleic acid content in the assessed crosses is controlled by one major effect locus. However, different dominant/recessive effects of the major locus were reported for both crosses. Additionally, a possible translocation between chromosome 7 and 14 was reported in one assessed cross. We defined a set of single nucleotide polymorphism markers for each cross which could be used for marker-assisted selection.


Assuntos
Helianthus , Helianthus/genética , Ácido Oleico , Mapeamento Cromossômico , Fenótipo , Ácidos Graxos/genética , Polimorfismo de Nucleotídeo Único
11.
J Virol ; 85(22): 11855-70, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21900160

RESUMO

Blattella germanica densovirus (BgDNV) is an autonomous parvovirus that infects the German cockroach. BgDNV possesses three mRNAs for NS proteins, two of which are splice variants of the unspliced transcript. The unspliced variant encodes open reading frame 5 (ORF5) (NS3), while NSspl1 encodes ORF3 (NS1) and ORF4 (NS2) and NSspl2 encodes the C-proximal half of NS1. BgDNV possesses three VP transcripts, one of which (VP) is unspliced, while the other two (VPspl1 and VPspl2) are generated by alternative splicing. The unspliced VP transcript contains both ORF1 and ORF2, while in VPspl1, ORF1 and ORF2 are joined in frame. The transcription of NS genes begins at an earlier stage of the virus life cycle than the transcription of VP genes. NS and VP transcripts overlap by 48 nucleotides (nt). BgDNV is characterized by two additional NS transcripts overlapping by more than 1,650 nt with VP-coding transcripts. Four different bands (97, 85, 80, and 57 kDa) corresponding to three BgDNV capsid proteins were detected on SDS-PAGE. Mass spectrometry analysis showed that the amino acid composition of the 85-kDa and 80-kDa proteins is the same. Moreover, both of these proteins are ubiquitinated. The BgDNV PLA(2) domain, which is critical for cellular uptake of the virus, is located in ORF2 and is present only in VP1. In contrast to all of the parvoviruses studied in this respect, VP2 has a unique N terminus that is not contained within VP1 and VP3. In situ recognition with NS1- and VP-specific antibodies revealed an uneven pattern of NS1 expression resembling a halo within the nuclear membrane.


Assuntos
Baratas/virologia , Densovirus/fisiologia , Regulação Viral da Expressão Gênica , Animais , Densovirus/crescimento & desenvolvimento , Eletroforese em Gel de Poliacrilamida , Espectrometria de Massas , Peso Molecular , Biossíntese de Proteínas , Splicing de RNA , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Transcrição Gênica , Proteínas Virais/biossíntese , Proteínas Virais/química
12.
Animals (Basel) ; 12(13)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35804591

RESUMO

Changes in the accuracy of the genomic estimates obtained by the ssGBLUP and wssGBLUP methods were evaluated using different reference groups. The weighting procedure's reasonableness of application Pwas considered to improve the accuracy of genomic predictions for meat, fattening and reproduction traits in pigs. Six reference groups were formed to assess the genomic data quantity impact on the accuracy of predicted values (groups of genotyped animals). The datasets included 62,927 records of meat and fattening productivity (fat thickness over 6-7 ribs (BF1, mm)), muscle depth (MD, mm) and precocity up to 100 kg (age, days) and 16,070 observations of reproductive qualities (the number of all born piglets (TNB) and the number of live-born piglets (NBA), according to the results of the first farrowing). The wssGBLUP method has an advantage over ssGBLUP in terms of estimation reliability. When using a small reference group, the difference in the accuracy of ssGBLUP over BLUP AM is from -1.9 to +7.3 percent points, while for wssGBLUP, the change in accuracy varies from +18.2 to +87.3 percent points. Furthermore, the superiority of the wssGBLUP is also maintained for the largest group of genotyped animals: from +4.7 to +15.9 percent points for ssGBLUP and from +21.1 to +90.5 percent points for wssGBLUP. However, for all analyzed traits, the number of markers explaining 5% of genetic variability varied from 71 to 108, and the number of such SNPs varied depending on the size of the reference group (79-88 for BF1, 72-81 for MD, 71-108 for age). The results of the genetic variation distribution have the greatest similarity between groups of about 1000 and about 1500 individuals. Thus, the size of the reference group of more than 1000 individuals gives more stable results for the estimation based on the wssGBLUP method, while using the reference group of 500 individuals can lead to distorted results of GEBV.

13.
G3 (Bethesda) ; 12(4)2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35150257

RESUMO

Tocopherols are antioxidants that preserve oil lipids against oxidation and serve as a natural source of vitamin E in the human diet. Compared with other major oilseeds like rapeseed and soybean, sunflower (Helianthus annuus L.) exhibits low phenotypic diversity of tocopherol composition, both in wild and cultivated accessions from germplasm collections. Two major mutations that alter tocopherol composition were identified in genetic collections, and several studies suggested additional loci controlling tocopherol composition, with their expression possibly depending on the genetic background. In the present study, we performed QTL mapping of tocopherol composition in two independent F2 crosses between lines with contrasting tocopherol composition from the Pustovoit All-Russia Research Institute of Oil Crops (VNIIMK) collection. We used genotyping-bysequencing (GBS) to construct single nucleotide polymorphism-based genetic maps, and performed QTL mapping using quantitative and qualitative encoding for phenotypic traits. Our results support the notion that the tocopherol composition in the assessed crosses is controlled by two loci. We additionally selected and validated two single nucleotide polymorphism markers for each cross which could be used for marker-assisted selection.


Assuntos
Helianthus , Óleos de Plantas , Tocoferóis , Mapeamento Cromossômico , Helianthus/genética , Fenótipo , Óleos de Plantas/química , Tocoferóis/química
14.
Animals (Basel) ; 11(6)2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34071766

RESUMO

Replacement pigs' genomic prediction for reproduction (total number and born alive piglets in the first parity), meat, fatness and growth traits (muscle depth, days to 100 kg and backfat thickness over 6-7 rib) was tested using single-step genomic best linear unbiased prediction ssGBLUP methodology. These traits were selected as the most economically significant and different in terms of heritability. The heritability for meat, fatness and growth traits varied from 0.17 to 0.39 and for reproduction traits from 0.12 to 0.14. We confirm from our data that ssGBLUP is the most appropriate method of genomic evaluation. The validation of genomic predictions was performed by calculating the correlation between preliminary GEBV (based on pedigree and genomic data only) with high reliable conventional estimates (EBV) (based on pedigree, own phenotype and offspring records) of validating animals. Validation datasets include 151 and 110 individuals for reproduction, meat and fattening traits, respectively. The level of correlation (r) between EBV and GEBV scores varied from +0.44 to +0.55 for meat and fatness traits, and from +0.75 to +0.77 for reproduction traits. Average breeding value (EBV) of group selected on genomic evaluation basis exceeded the group selected on parental average estimates by 22, 24 and 66% for muscle depth, days to 100 kg and backfat thickness over 6-7 rib, respectively. Prediction based on SNP markers data and parental estimates showed a significant increase in the reliability of low heritable reproduction traits (about 40%), which is equivalent to including information about 10 additional descendants for sows and 20 additional descendants for boars in the evaluation dataset.

15.
Genes (Basel) ; 11(8)2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32806588

RESUMO

Rapeseed is the second most common oilseed crop worldwide. While the start of rapeseed breeding in Russia dates back to the middle of the 20th century, its widespread cultivation began only recently. In contrast to the world's rapeseed genetic variation, the genetic composition of Russian rapeseed lines remained unexplored. We have addressed this question by performing genome-wide genotyping of 90 advanced rapeseed accessions provided by the All-Russian Research Institute of Oil Crops (VNIIMK). Genome-wide genetic analysis demonstrated a clear difference between Russian rapeseed varieties and the rapeseed varieties from the rest of the world, including the European ones, indicating that rapeseed breeding in Russia proceeded in its own independent direction. Hence, genetic determinants of agronomical traits might also be different in Russian rapeseed lines. To assess it, we collected the glucosinolate content data for the same 90 genotyped accessions obtained during three years and performed an association mapping of this trait. We indeed found that the loci significantly associated with glucosinolate content variation in the Russian rapeseed collection differ from those previously reported for the non-Russian rapeseed lines.


Assuntos
Brassica napus/genética , Brassica napus/metabolismo , Mapeamento Cromossômico , Glucosinolatos/metabolismo , Locos de Características Quantitativas , Característica Quantitativa Herdável , Biologia Computacional/métodos , Estudos de Associação Genética , Variação Genética , Genética Populacional , Genótipo , Anotação de Sequência Molecular , Fenótipo , Melhoramento Vegetal , Polimorfismo de Nucleotídeo Único , Sementes
16.
Transl Anim Sci ; 4(1): 264-274, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32704985

RESUMO

Genomic selection is routinely used worldwide in agricultural breeding. However, in Russia, it is still not used to its full potential partially due to high genotyping costs. The use of genotypes imputed from the low-density chips (LD-chip) provides a valuable opportunity for reducing the genotyping costs. Pork production in Russia is based on the conventional 3-tier pyramid involving 3 breeds; therefore, the best option would be the development of a single LD-chip that could be used for all of them. Here, we for the first time have analyzed genomic variability in 3 breeds of Russian pigs, namely, Landrace, Duroc, and Large White and generated the LD-chip that can be used in pig breeding with the negligible loss in genotyping quality. We have demonstrated that out of the 3 methods commonly used for LD-chip construction, the block method shows the best results. The imputation quality depends strongly on the presence of close ancestors in the reference population. We have demonstrated that for the animals with both parents genotyped using high-density panels high-quality genotypes (allelic discordance rate < 0.05) could be obtained using a 300 single nucleotide polymorphism (SNP) chip, while in the absence of genotyped ancestors at least 2,000 SNP markers are required. We have shown that imputation quality varies between chromosomes, and it is lower near the chromosome ends and drops with the increase in minor allele frequency. Imputation quality of the individual SNPs correlated well across breeds. Using the same LD-chip, we were able to obtain comparable imputation quality in all 3 breeds, so it may be suggested that a single chip could be used for all of them. Our findings also suggest that the presence of markers with extremely low imputation quality is likely to be explained by wrong mapping of the markers to the chromosomal positions.

17.
Sci Rep ; 10(1): 8697, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32457493

RESUMO

Darevskia rock lizards is a unique complex taxa, including more than thirty species, seven of which are parthenogenetic. In mixed populations of Darevskia lizards, tri- and tetraploid forms can be found. The most important issues in the theory of reticulate evolution of Darevskia lizards are the origin of parthenogenetic species and their taxonomic position. However, there is little data on how meiosis proceeds in these species. The present work reports the complex results of cytogenetics in a diploid parthenogenetic species - D. unisexualis. Here we detail the meiotic prophase I progression and the specific features оf mitotic chromosomes organization. The stages of meiosis prophase I were investigated by immunocytochemical analysis of preparations obtained from isolated primary oocytes of D. unisexualis in comparison with maternal species D. raddei nairensis. It has been shown that in D. unisexualis at the leptotene-zygotene stages the axial elements and the synaptonemal complex (SC) form typical "bouquets". At the pachytene-diplotene stage, 18 autosomal SC-bivalents and thickened asynapted sex Z and w univalents were observed. The presence of SYCP1 protein between the lateral elements of autosomal chromosomes proved the formation of assembled SCs. Comparative genomic hybridization (CGH) on the mitotic metaphase chromosomes of D. unisexualis was carried out using the genomic DNA isolated from the parental species D. raddei nairensis and D. valentini. In the pericentromeric regions of half of the mitotic chromosomes of D. unisexualis, specific regions inherited from maternal species have been found. Following our results, we suggest a model for diploid germ cells formation from diploid oocytes without premeiotic duplication of chromosomes in the oogenesis of diploid parthenogenetic lizards D. unisexualis. Taken as a whole, our findings confirm the hybrid nature of D. unisexualis and shed light on heterozygosity and automixis in diploid parthenogenetic forms.


Assuntos
Hibridização Genômica Comparativa/métodos , Lagartos/genética , Animais , Cromossomos , Hibridização in Situ Fluorescente , Cariótipo , Lagartos/crescimento & desenvolvimento , Meiose , Oócitos/metabolismo , Oogênese
18.
Open Biol ; 9(12): 190220, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31847788

RESUMO

Gata3 is a DNA-binding transcription factor involved in cellular differentiation in a variety of tissues including inner ear, hair follicle, kidney, mammary gland and T-cells. In a previous study in 2009, Maeda et al. (Dev. Dyn.238, 2280-2291; doi:10.1002/dvdy.22035) found that Gata3 mutants could be rescued from midgestational lethality by the expression of a Gata3 transgene in sympathoadrenal neuroendocrine cells. The rescued embryos clearly showed multiple defects in lens fibre cell differentiation. To determine whether these defects were truly due to the loss of Gata3 expression in the lens, we generated a lens-specific Gata3 loss-of-function model. Analogous to the previous findings, our Gata3 null embryos showed abnormal regulation of cell cycle exit during lens fibre cell differentiation, marked by reduction in the expression of the cyclin-dependent kinase inhibitors Cdkn1b/p27 and Cdkn1c/p57, and the retention of nuclei accompanied by downregulation of Dnase IIß. Comparisons of transcriptomes between control and mutated lenses by RNA-Seq revealed dysregulation of lens-specific crystallin genes and intermediate filament protein Bfsp2. Both Cdkn1b/p27 and Cdkn1c/p57 loci are occupied in vivo by Gata3, as well as Prox1 and c-Jun, in lens chromatin. Collectively, our studies suggest that Gata3 regulates lens differentiation through the direct regulation of the Cdkn1b/p27and Cdkn1c/p57 expression, and the direct/or indirect transcriptional control of Bfsp2 and Dnase IIß.


Assuntos
Diferenciação Celular/genética , Fator de Transcrição GATA3/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Cristalino/citologia , Transcriptoma , Alelos , Animais , Inibidor de Quinase Dependente de Ciclina p27/genética , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Inibidor de Quinase Dependente de Ciclina p57/genética , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Fator de Transcrição GATA3/genética , Imuno-Histoquímica , Cristalino/embriologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Modelos Biológicos , Mutação
19.
PeerJ ; 7: e6547, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30863679

RESUMO

Oilseed crops are one of the most important sources of vegetable oils for food and industry. Nutritional and technical properties of vegetable oil are primarily determined by its fatty acid (FA) composition. The content and composition of FAs in plants are commonly determined using gas chromatography-mass spectrometry (GS-MS) or gas chromatography-flame ionization detection (GC-FID) techniques. In the present work, we applied ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) technique to FA profiling of sunflower and rapeseed seeds and compared this method with the GC-FID technique. GC-FID detected 11 FAs in sunflower and 13 FAs in rapeseed, while UPLC-MS appeared to be more sensitive, detecting about 2.5 times higher numbers of FAs in both plants. In addition to even-chain FAs, UPLC-MS was able to detect odd-chain FAs. The longest FA detected using GC-FID was an FA with 24 carbon atoms, whereas UPLC-MS could reveal the presence of longer FAs with the tails of up to 28 carbon atoms. Based on our results, we may conclude that UPLC-MS has great potential to be used for the assessment of FA profiles of oil crops.

20.
Viruses ; 10(7)2018 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-30011943

RESUMO

Densovirus genome replication and capsid assembly take place in the nucleus of the infected cells. However, the mechanisms underlying such processes as the delivery of virus proteins to the nucleus and the export of progeny virus from the nucleus remain elusive. It is evident that nuclear transport signals should be involved in these processes. We performed an in silico search for the putative nuclear localization signal (NLS) and nuclear export signal (NES) motifs in the capsid proteins of the Blattella germanica Densovirus 1 (BgDV1) densovirus. A high probability NLS motif was found in the common C-terminal of capsid proteins together with a NES motif in the unique N-terminal of VP2. We also performed a global search for the nuclear traffic signals in the densoviruses belonging to five Densovirinae genera, which revealed high diversity in the patterns of NLSs and NESs. Using a heterologous system, the HeLa mammalian cell line expressing GFP-fused BgDV1 capsid proteins, we demonstrated that both signals are functionally active. We suggest that the NLS shared by all three BgDV1 capsid proteins drives the trafficking of the newly-synthesized proteins into the nucleus, while the NES may play a role in the export of the newly-assembled BgDV1 particles into the cytoplasm through nuclear pore complexes.


Assuntos
Proteínas do Capsídeo/química , Núcleo Celular/virologia , Citoplasma/química , Densovirus/química , Motivos de Aminoácidos , Capsídeo/química , Proteínas do Capsídeo/genética , Densovirus/genética , Genoma Viral , Células HeLa , Humanos , Mutagênese Sítio-Dirigida , Sinais de Exportação Nuclear , Sinais de Localização Nuclear , Transporte Proteico , Proteínas Virais
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