31 results on '"Pasentsis, Konstantinos"'
Search Results
2. Comparison of different strategies for the triage to colposcopy of women tested high-risk HPV positive on self-collected cervicovaginal samples
- Author
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Chatzistamatiou, Kimon, Tsertanidou, Athena, Moysiadis, Theodoros, Mouchtaropoulou, Evangelia, Pasentsis, Konstantinos, Skenderi, Alkmini, Stamatopoulos, Kostas, and Agorastos, Theodoros
- Published
- 2021
- Full Text
- View/download PDF
3. A meta-barcoding approach to assess and compare the storage temperature-dependent bacterial diversity of gilt-head sea bream (Sparus aurata) originating from fish farms from two geographically distinct areas of Greece
- Author
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Parlapani, Foteini F., Michailidou, Sofia, Pasentsis, Konstantinos, Argiriou, Anagnostis, Krey, Grigorios, and Boziaris, Ioannis S.
- Published
- 2018
- Full Text
- View/download PDF
4. High risk HPV-positive women cervicovaginal microbial profiles in a Greek cohort: a retrospective analysis of the GRECOSELF study.
- Author
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Sofou, Electra, Gkoliou, Glykeria, Pechlivanis, Nikolaos, Pasentsis, Konstantinos, Chatzistamatiou, Kimon, Psomopoulos, Fotis, Agorastos, Theodoros, and Stamatopoulos, Kostas
- Subjects
NUCLEOTIDE sequencing ,HUMAN papillomavirus ,CERVICAL intraepithelial neoplasia ,COHORT analysis ,RETROSPECTIVE studies - Abstract
Increasing evidence supports a role for the vaginal microbiome (VM) in the severity of HPV infection and its potential link to cervical intraepithelial neoplasia. However, a lot remains unclear regarding the precise role of certain bacteria in the context of HPV positivity and persistence of infection. Here, using next generation sequencing (NGS), we comprehensively profiled the VM in a series of 877 women who tested positive for at least one high risk HPV (hrHPV) type with the COBAS® 4,800 assay, after self-collection of a cervico-vaginal sample. Starting from gDNA, we PCR amplified the V3-V4 region of the bacterial 16S rRNA gene and applied a paired-end NGS protocol (Illumina). We report significant differences in the abundance of certain bacteria compared among different HPV-types, more particularly concerning species assigned to Lacticaseibacillus, Megasphaera and Sneathia genera. Especially for Lacticaseibacillus, we observed significant depletion in the case of HPV16, HPV18 versus hrHPVother. Overall, our results suggest that the presence or absence of specific cervicovaginal microbial genera may be linked to the observed severity in hrHPV infection, particularly in the case of HPV16, 18 types. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Molecular studies of inheritable grafting induced changes in pepper (Capsicum annuum) fruit shape
- Author
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Tsaballa, Aphrodite, Athanasiadis, Christos, Pasentsis, Konstantinos, Ganopoulos, Ioannis, Nianiou-Obeidat, Irini, and Tsaftaris, Athanasios
- Published
- 2013
- Full Text
- View/download PDF
6. The study of the E-class SEPALLATA3-like MADS-box genes in wild-type and mutant flowers of cultivated saffron crocus ( Crocus sativus L.) and its putative progenitors
- Author
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Tsaftaris, Athanasios, Pasentsis, Konstantinos, Makris, Antonios, Darzentas, Nikos, Polidoros, Alexios, Kalivas, Apostolos, and Argiriou, Anagnostis
- Published
- 2011
- Full Text
- View/download PDF
7. Identification and expression profiling of low oxygen regulated genes from Citrus flavedo tissues using RT-PCR differential display
- Author
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Pasentsis, Konstantinos, Falara, Vasiliki, Pateraki, Irene, Gerasopoulos, Dimitrios, and Kanellis, Angelos K.
- Published
- 2007
8. Cloning and Characterization of FLOWERING LOCUS T-Like Genes from the Perennial Geophyte Saffron Crocus (Crocus sativus)
- Author
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Tsaftaris, Athanasios, Pasentsis, Konstantinos, and Argiriou, Anagnostis
- Published
- 2013
- Full Text
- View/download PDF
9. Isolation of a CENTRORADIALIS/TERMINAL FLOWER1 homolog in saffron (Crocus sativus L.): characterization and expression analysis
- Author
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Tsaftaris, Athanasios, Pasentsis, Konstantinos, Kalivas, Apostolos, Michailidou, Sofia, Madesis, Panagiotis, and Argiriou, Anagnostis
- Published
- 2012
- Full Text
- View/download PDF
10. Τhe Role of a Gibberellin 20-Oxidase Gene in Fruit Development in Pepper (Capsicum annuum)
- Author
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Tsaballa, Aphrodite, Pasentsis, Konstantinos, and Tsaftaris, Athanasios S.
- Published
- 2012
- Full Text
- View/download PDF
11. Sequence Characterization and Expression Analysis of Three APETALA2-like Genes from Saffron Crocus
- Author
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Tsaftaris, Athanasios S., Pasentsis, Konstantinos, Madesis, Panagiotis, and Argiriou, Anagnostis
- Published
- 2012
- Full Text
- View/download PDF
12. Isolation, Characterization, and Expression Analysis of an NAP-Like cDNA from Crocus (Crocus sativus L.)
- Author
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Kalivas, Apostolos, Pasentsis, Konstantinos, Argiriou, Anagnostis, and Tsaftaris, Athanasios S.
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- 2010
- Full Text
- View/download PDF
13. Tepal formation and expression pattern of B-class paleo AP3-like MADS-box genes in crocus ( Crocus sativus L.)
- Author
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Tsaftaris, Athanasios S., Polidoros, Alexios N., Pasentsis, Konstantinos, and Kalivas, Apostolos
- Published
- 2006
- Full Text
- View/download PDF
14. Isolation of three homologous AP1-like MADS-box genes in crocus ( Crocus sativus L.) and characterization of their expression
- Author
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Tsaftaris, Athanasios S., Pasentsis, Konstantinos, Iliopoulos, Ioannis, and Polidoros, Alexios N.
- Published
- 2004
- Full Text
- View/download PDF
15. Multiple evidence for the role of an Ovate-like gene in determining fruit shape in pepper
- Author
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Tsaftaris Athanasios S, Darzentas Nikos, Pasentsis Konstantinos, and Tsaballa Aphrodite
- Subjects
Botany ,QK1-989 - Abstract
Abstract Background Grafting is a widely used technique contributing to sustainable and ecological production of many vegetables, but important fruit quality characters such as taste, aroma, texture and shape are known for years to be affected by grafting in important vegetables species including pepper. From all the characters affected, fruit shape is the most easily observed and measured. From research in tomato, fruit shape is known to be controlled by many QTLs but only few of them have larger effect on fruit shape variance. In this study we used pepper cultivars with different fruit shape to study the role of a pepper Ovate-like gene, CaOvate, which encodes a negative regulator protein that brings significant changes in tomato fruit shape. Results We successfully cloned and characterized Ovate-like genes (designated as CaOvate) from two pepper cultivars of different fruit shape, cv. "Mytilini Round" and cv. "Piperaki Long", hereafter referred to as cv. "Round" and cv. "Long" after the shape of their mature fruits. The CaOvate consensus contains a 1008-bp ORF, encodes a 335 amino-acid polypeptide, shares 63% identity with the tomato OVATE protein and exhibits high similarity with OVATE sequences from other Solanaceae species, all placed in the same protein subfamily as outlined by expert sequence analysis. No significant structural differences were detected between the CaOvate genes obtained from the two cultivars. However, relative quantitative expression analysis showed that the expression of CaOvate followed a different developmental profile between the two cultivars, being higher in cv. "Round". Furthermore, down-regulation of CaOvate through VIGS in cv. "Round" changes its fruit to a more oblong form indicating that CaOvate is indeed involved in determining fruit shape in pepper, perhaps by negatively affecting the expression of its target gene, CaGA20ox1, also studied in this work. Conclusions Herein, we clone, characterize and study CaOvate and CaGA20ox1 genes, very likely involved in shaping pepper fruit. The oblong phenotype of the fruits in a plant of cv. "Round", where we observed a significant reduction in the expression levels of CaOvate, resembled the change in shape that takes place by grafting the round-fruited cultivar cv. "Round" onto the long-fruited pepper cultivar cv. "Long". Understanding the role of CaOvate and CaGA20ox1, as well as of other genes like Sun also involved in controlling fruit shape in Solanaceae plants like tomato, pave the way to better understand the molecular mechanisms involved in controlling fruit shape in Solanaceae plants in general, and pepper in particular, as well as the changes in fruit quality induced after grafting and perhaps the ways to mitigate them.
- Published
- 2011
- Full Text
- View/download PDF
16. Characterization and expression of the phytochrome gene family in the moss Ceratodon purpureus
- Author
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Pasentsis, Konstantinos, Paulo, Nicola, Algarra, Patricia, Dittrich, Peter, and Thümmler, Fritz
- Published
- 1998
17. Acceptability of Self-Sampling for Human Papillomavirus-Based Cervical Cancer Screening.
- Author
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Chatzistamatiou, Kimon, Vrekoussis, Thomas, Tsertanidou, Athena, Moysiadis, Theodoros, Mouchtaropoulou, Evangelia, Pasentsis, Konstantinos, Kitsou, Anastasia, Moschaki, Viktoria, Ntoula, Maria, Zempili, Paraskevi, Halatsi, Despina, Truva, Theoni, Piha, Vaia, Agelena, Georgia, Daponte, Alexandros, Vanakara, Polyxeni, Paschopoulos, Minas, Stefos, Theodoros, Lymberis, Vasilis, and Kontomanolis, Emmanuel N.
- Subjects
TUMOR prevention ,CERVIX uteri tumors ,COLLECTION & preservation of biological specimens ,COMMUNICATION ,CONFIDENCE ,PAIN ,PAPILLOMAVIRUSES ,RURAL conditions ,MEDICAL self-examination ,VULVA ,PREDICTIVE tests ,CROSS-sectional method ,HOME diagnostic tests ,DESCRIPTIVE statistics ,EARLY detection of cancer - Abstract
Background: Human papillomavirus (HPV)-DNA testing combined with self-sampling could increase cervical cancer screening effectiveness, utilizing a sensitive screening modality and an easy sampling method with minimal pain or discomfort. Self-sampling acceptability, though, is pivotal. Materials and Methods: This study is a nested cross-sectional survey within GRECOSELF, a cross-sectional study on HPV-based screening with self-sampling, aiming at investigating self-sampling acceptability among Greek women residing in rural areas, and the factors affecting it. Women between 25 and 60 years old were recruited by midwives participating in a nationwide midwifery network. Participants, after self-sampling, filled out a questionnaire with three sections, one regarding demographic characteristics, a second with questions pertaining to the participants' cervical cancer screening history, and a third with questions regarding the self-sampling process per se. Results: The sample included 13,111 women. Most participants (67.9%), including those screened or not in the past, would prefer self-sampling if assured that the results are not inferior to standard testing. Discomfort or pain during self-sampling was absent or minimal in 97.1% and 96.5% of the cases, respectively, and 74.4% of the women felt adequately confident that they followed the instructions correctly. Women mostly preferred selfsampling at home compared with health care facilities. Pain and discomfort during the procedure, although rare, were significant factors against acceptance. Most of the women reporting a negative impression had a negative experience with conventional sampling in the past. Conclusion: Self-sampling is highly acceptable. Acceptance can be further improved with proper communication of the process and its noninferiority compared with conventional screening. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
18. Analysis of Microbial Community Dynamics during the Acclimatization Period of a Membrane Bioreactor Treating Table Olive Processing Wastewater.
- Author
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Patsios, Sotiris I., Michailidou, Sofia, Pasentsis, Konstantinos, Makris, Antonios M., Argiriou, Anagnostis, and Karabelas, Anastasios J.
- Subjects
SEWAGE ,OLIVE ,NUCLEOTIDE sequencing ,ACCLIMATIZATION ,BIOMASS ,MICROBIAL communities - Abstract
Feature Application: The novel data and insights obtained in this study are expected to provide guidance in the start-up of large-scale applications of membrane bioreactor process for biological treatment of difficult to degrade table olive processing wastewater. Biological treatment of table olive processing wastewater (TOPW) may be problematic due to its high organic and polyphenolic compound content. Biomass acclimatization is a necessary, yet sensitive, stage for efficient TOPW biological treatment. Next-generation sequencing technologies can provide valuable insights into this critical process step. An aerobic membrane bioreactor (MBR) system, initially inoculated with municipal activated sludge, was acclimatized to treat TOPW. Operational stability and bioremediation efficiency were monitored for approx. three months, whereas microbial community dynamics and metabolic adaptation were assessed through metagenomic and metatranscriptomic analysis. A swift change was identified in both the prokaryotic and eukaryotic bio-community after introduction of TOPW in the MBR, and a new diverse bio-community was established. Thauera and Paracoccus spp. are dominant contributors to the metabolic activity of the stable bio-community, which resulted in over 90% and 85% removal efficiency of total organic carbon and total polyphenols, respectively. This is the first study assessing the microbial community dynamics in a well-defined MBR process treating TOPW, offering guidance in the start-up of large-scale applications. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
19. Integrated epigenomic and transcriptomic analysis reveals TP63 as a novel player in clinically aggressive chronic lymphocytic leukemia.
- Author
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Papakonstantinou, Nikos, Ntoufa, Stavroula, Tsagiopoulou, Maria, Moysiadis, Theodoros, Bhoi, Sujata, Malousi, Andigoni, Psomopoulos, Fotis, Mansouri, Larry, Laidou, Stamatia, Papazoglou, Despoina, Gounari, Maria, Pasentsis, Konstantinos, Plevova, Karla, Kuci‐Emruli, Venera, Duran‐Ferrer, Marti, Davis, Zadie, Ek, Sara, Rossi, Davide, Gaidano, Gianluca, and Ritgen, Matthias
- Abstract
Chronic lymphocytic leukemia (CLL) stereotyped subsets #6 and #8 include cases expressing unmutated B cell receptor immunoglobulin (BcR IG) (U‐CLL). Subset #6 (IGHV1‐69/IGKV3‐20) is less aggressive compared to subset #8 (IGHV4‐39/IGKV1(D)‐39) which has the highest risk for Richter's transformation among all CLL. The underlying reasons for this divergent clinical behavior are not fully elucidated. To gain insight into this issue, here we focused on epigenomic signatures and their links with gene expression, particularly investigating genome‐wide DNA methylation profiles in subsets #6 and #8 as well as other U‐CLL cases not expressing stereotyped BcR IG. We found that subset #8 showed a distinctive DNA methylation profile compared to all other U‐CLL cases, including subset #6. Integrated analysis of DNA methylation and gene expression revealed significant correlation for several genes, particularly highlighting a relevant role for the TP63 gene which was hypomethylated and overexpressed in subset #8. This observation was validated by quantitative PCR, which also revealed TP63 mRNA overexpression in additional nonsubset U‐CLL cases. BcR stimulation had distinct effects on p63 protein expression, particularly leading to induction in subset #8, accompanied by increased CLL cell survival. This pro‐survival effect was also supported by siRNA‐mediated downregulation of p63 expression resulting in increased apoptosis. In conclusion, we report that DNA methylation profiles may vary even among CLL patients with similar somatic hypermutation status, supporting a compartmentalized approach to dissecting CLL biology. Furthermore, we highlight p63 as a novel prosurvival factor in CLL, thus identifying another piece of the complex puzzle of clinical aggressiveness. What's new? In chronic lymphocytic leukemia (CLL), cases with unmutated immunoglobulin receptors (U‐CLL) are generally associated with inferior outcome, albeit still displaying considerable heterogeneity. Might such differences in CLL progression be explained by epigenetics? In this study, the authors found that an unusually aggressive subset of CLLs called "subset #8" has a distinctive DNA‐methylation profile. They also found that p63 is a novel pro‐survival factor for CLL cells. These molecular studies may lead to new prognostic biomarkers, and possibly new therapeutic targets, for CLL. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
20. Cloning, Structural Characterization, and Phylogenetic Analysis of Flower MADS-Box Genes from Crocus (Crocus sativus L.)
- Author
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Tsaftaris, Athanasios S., Polidoros, Alexios N., Pasentsis, Konstantinos, and Kalivas, Apostolos
- Subjects
Article Subject ,food and beverages - Abstract
Crocus (Crocus sativus L.) is a crop species cultivated for its flowers and, more specifically, for its red stigmas. The flower of crocus is bisexual and sterile, since crocus is a triploid species. Its perianth consists of six petaloid tepals: three tepals in whorl 1 (outer tepals) and three tepals in whorl 2 (inner tepals). The androecium consists of three distinct stamens and the gynoecium consists of a single compound pistil with three carpels, a single three-branched style, and an inferior ovary. The dry form of the stigmas constitutes the commercial saffron used as a food additive, in the coloring industry, and in medicine. In order to uncover and understand the molecular mechanisms controlling flower development in cultivated crocus and its relative wild progenitor species, and characterize a number of crocus flower mutants, we have cloned and characterized different, full-length, cDNA sequences encoding MADS-box transcription factor proteins involved in flower formation.Here we review the different methods followed or developed for obtaining these sequences involving conventional 5' 3' RACE, as well as newly developed methods from our group, named Rolling Circle Amplification – RACE (RCA-RACE) and its modification named familyRCA-RACE (famRCA-RACE). Furthermore, the characteristics of the protein structure and their common and specific domains for each type of MADS-box transcription factors in this lower nongrass monocot belonging to the Iridaceae family are described. Finally, a phylogenetic tree of all the MADS-box sequences available in our lab is presented and discussed in relation to other data from studies of species of the Iridaceae group and closely related families from an evolutionary perspective. The structural and phylogenetic analyses are based on both published and unpublished data.
- Published
- 2007
- Full Text
- View/download PDF
21. Cloning and Characterization of FLOWERING LOCUS T-Like Genes from the Perennial Geophyte Saffron Crocus (Crocus sativus)
- Author
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Tsaftaris, Athanasios, Pasentsis, Konstantinos, and Argiriou, Anagnostis
- Subjects
MOLECULAR cloning ,SAFFRON crocus ,ANGIOSPERMS ,PLANT genes ,PHOSPHATIDYLETHANOLAMINES ,CARRIER proteins ,MONOCOTYLEDONS ,AMINO acid analysis - Abstract
The transition to flowering is one of the most important developmental decisions made by plants. At the molecular level, many genes coordinate this transition. Among these, genes encoding for phosphatidylethanolamine-binding proteins (PEBPs) play important roles in regulating flower time and the fate of inflorescence meristem. To investigate the role of PEBPs in an industrially important crop cultivated for its nutritional and medicinal properties, the monocotyledonous species Crocus sativus L., we have isolated three FLOWERING LOCUS T ( FT)-like genes designated as CsatFT1-like, CsatFT2-like, and CsatFT3-like. The isolated genes maintain the exon/intron organization of FT-like genes and encode proteins similar to the members of the PEBP family. Phylogenetic and amino acid analysis at critical positions confirmed that the isolated sequence belongs to the FT clade of the PEBP family phylogeny distinctly from the TERMINAL FLOWER 1 ( TFL1) and MOTHER OF FT AND TFL1 clades. Expression analysis indicated differences in the expression of the three FT-like genes in different organs and different expressions during the day–night diurnal clock. Additionally, analysis of isolated promoter sequences using computational methods reveals the preservation of common binding motifs in FT-like promoters from other species, thus suggesting their importance among plant species. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
22. Taxonomic Identification of Mediterranean Pines and Their Hybrids Based on the High Resolution Melting (HRM) and trnL Approaches: From Cytoplasmic Inheritance to Timber Tracing.
- Author
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Ganopoulos, Ioannis, Aravanopoulos, Filippos, Madesis, Panagiotis, Pasentsis, Konstantinos, Bosmali, Irene, Ouzounis, Christos, and Tsaftaris, Athanasios
- Subjects
PINE ,MELTING ,CYTOPLASMIC inheritance ,PLANT genetics ,COMPUTATIONAL biology ,PLANT classification ,PLANT ecology ,SPECIES diversity - Abstract
Fast and accurate detection of plant species and their hybrids using molecular tools will facilitate the assessment and monitoring of local biodiversity in an era of climate and environmental change. Herein, we evaluate the utility of the plastid trnL marker for species identification applied to Mediterranean pines (Pinus spp.). Our results indicate that trnL is a very sensitive marker for delimiting species biodiversity. Furthermore, High Resolution Melting (HRM) analysis was exploited as a molecular fingerprint for fast and accurate discrimination of Pinus spp. DNA sequence variants. The trnL approach and the HRM analyses were extended to wood samples of two species (Pinus nigra and Pinus sylvestris) with excellent results, congruent to those obtained using leaf tissue. Both analyses demonstrate that hybrids from the P. brutia (maternal parent) × P. halepensis (paternal parent) cross, exhibit the P. halepensis profile, confirming paternal plastid inheritance in Group Halepensis pines. Our study indicates that a single one-step reaction method and DNA marker are sufficient for the identification of Mediterranean pines, their hybrids and the origin of pine wood. Furthermore, our results underline the potential for certain DNA regions to be used as novel biological information markers combined with existing morphological characters and suggest a relatively reliable and open taxonomic system that can link DNA variation to phenotype-based species or hybrid assignment status and direct taxa identification from recalcitrant tissues such as wood samples. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
23. Multiple evidence for the role of an Ovate-like gene in determining fruit shape in pepper.
- Author
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Tsaballa, Aphrodite, Pasentsis, Konstantinos, Darzentas, Nikos, and Tsaftaris, Athanasios S.
- Subjects
PEPPERS ,GRAFTING (Horticulture) ,TOMATOES ,VEGETABLES ,GENES - Abstract
Background: Grafting is a widely used technique contributing to sustainable and ecological production of many vegetables, but important fruit quality characters such as taste, aroma, texture and shape are known for years to be affected by grafting in important vegetables species including pepper. From all the characters affected, fruit shape is the most easily observed and measured. From research in tomato, fruit shape is known to be controlled by many QTLs but only few of them have larger effect on fruit shape variance. In this study we used pepper cultivars with different fruit shape to study the role of a pepper Ovate-like gene, CaOvate, which encodes a negative regulator protein that brings significant changes in tomato fruit shape. Results: We successfully cloned and characterized Ovate-like genes (designated as CaOvate) from two pepper cultivars of different fruit shape, cv. "Mytilini Round" and cv. "Piperaki Long", hereafter referred to as cv. "Round" and cv. "Long" after the shape of their mature fruits. The CaOvate consensus contains a 1008-bp ORF, encodes a 335 amino-acid polypeptide, shares 63% identity with the tomato OVATE protein and exhibits high similarity with OVATE sequences from other Solanaceae species, all placed in the same protein subfamily as outlined by expert sequence analysis. No significant structural differences were detected between the CaOvate genes obtained from the two cultivars. However, relative quantitative expression analysis showed that the expression of CaOvate followed a different developmental profile between the two cultivars, being higher in cv. "Round". Furthermore, down-regulation of CaOvate through VIGS in cv. "Round" changes its fruit to a more oblong form indicating that CaOvate is indeed involved in determining fruit shape in pepper, perhaps by negatively affecting the expression of its target gene, CaGA20ox1, also studied in this work. Conclusions: Herein, we clone, characterize and study CaOvate and CaGA20ox1 genes, very likely involved in shaping pepper fruit. The oblong phenotype of the fruits in a plant of cv. "Round", where we observed a significant reduction in the expression levels of CaOvate, resembled the change in shape that takes place by grafting the round-fruited cultivar cv. "Round" onto the long-fruited pepper cultivar cv. "Long". Understanding the role of CaOvate and CaGA20ox1, as well as of other genes like Sun also involved in controlling fruit shape in Solanaceae plants like tomato, pave the way to better understand the molecular mechanisms involved in controlling fruit shape in Solanaceae plants in general, and pepper in particular, as well as the changes in fruit quality induced after grafting and perhaps the ways to mitigate them. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
24. famRCA-RACE: A ROLLING CIRCLE AMPLIFICATION RACE FOR ISOLATING A FAMILY OF HOMOLOGOUS cDNAs IN ONE REACTION AND ITS APPLICATION TO OBTAIN NAC GENES TRANSCRIPTION FACTORS FROM CROCUS (CROCUS SATIVUS) FLOWER.
- Author
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Kalivas, Apostolos, Pasentsis, Konstantinos, Argiriou, Anagnostis, Darzentas, Nikos, and Tsaftaris, AthanasiosS.
- Subjects
- *
DNA synthesis , *NUCLEOTIDE sequence , *SAFFRON crocus , *GENE expression , *TRANSCRIPTION factors - Abstract
We describe an improvement of the RCA-RACE (rolling circle amplification—rapid amplification of cDNA ends) method, called family RCA-RACE (famRCA-RACE). The method is based on the generation of circular cDNA fragments, followed by rolling circle amplification of the circular cDNA using ϕ29 DNA polymerase and the application of PCR using degenerate outworking primers, designed for a conserved region of homologous genes, that allows the isolation of homologous cDNA sequences expressed in the mRNA preparation in a single polymerase chain reaction (PCR). As an example we present the isolation of seven NAC-like transcription factors cDNA sequences expressed in Crocus sativus flower, used for saffron production. Sequence alignment revealed that CsatNAC proteins contain the typical domain structure of plant NAC proteins, consisting of the conserved N-terminal NAC domain used to design the primers and the five subdomains. Phylogenetic analysis revealed that CsatNAC proteins fall in subgroup I of the NAC family of proteins. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
25. Identification of unknown genetically modified material admixed in conventional cotton seed and development of an event-specific detection method.
- Author
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Akritidis, Paschalis, Pasentsis, Konstantinos, Tsaftaris, Athanasios S., Mylona, Photini V., and Polidoros, Alexios N.
- Subjects
- *
COTTON , *BIOTECHNOLOGY industries , *TRANSGENIC plants , *GENOMES , *POLYMERASE chain reaction , *NONGOVERNMENTAL organizations - Abstract
Entering the second decade of commercialization of biotech crops, the global area cultivated with transgenic plants constantly expands and national legislations in many countries, particularly in the European Union, require identification and labeling of genetically modified material in food and feed. We describe here a procedure for characterizing transgenic material of unknown origin present in conventional seed lots using a genome walking strategy for isolation and characterization of the junction between the inserted transgene construct and the host plant genomic DNA. The procedure was applied to transgenic cotton detected as adventitious or technically unavoidable presence in a conventional commercial cultivar. The structure of the isolated region revealed that the transgenic material derived from Monsanto's event 1445 transgenic cotton. Due to the random incorporation of the transgene into the host plant's genome, the sequence of the junction region obtained using the genome walking strategy, provided the means to develop an event-specific identification method without prior knowledge for the nature of the transformation event. Thus, we documented a methodology for developing an event-specific detection protocol even without prior knowledge of the genetic modification event. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
26. Heterotopic expression of B-class floral homeotic genes PISTILLATA/GLOBOSA supports a modified model for crocus (Crocus sativus L.) flower formation.
- Author
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Kalivas, Apostolos, Pasentsis, Konstantinos, Polidoros, Alexios N., and Tsaftaris, Athanasios S.
- Subjects
- *
HOMEOBOX genes , *CROCUSES , *SAFFRON crocus , *FLOWERS , *ARABIDOPSIS thaliana , *PLANT genetics - Abstract
For uncovering and understanding the molecular mechanisms controlling flower development in cultivated Crocus sativus and particularly the transformation of sepals in outer whorl (whorl 1) tepals, we have cloned and characterized the expression of a family of five PISTILLATA/GLOBOSA-like (PI/GLO-like) MADS-box genes expressed in the C. sativus flower. The deduced amino acid sequences of the coded proteins indicated high homology with members of the MADS-box family of transcription factors, and particularly with other members of the PI/GLO family of MADS-box proteins that control floral organ identity. PI/GLO expression studies in cultivated C. sativus uncover the presence of PI/GLO transcripts not only in the second and third whorls of flower organs as expected, but also in the outer whorl tepals that are the sepals in most typical flowers. This heterotopic expression of both B-class genes: PI/GLO and AP3/DEF, known to form heterodimers for stamens and petals (petaloid inner whor l–whorl 2-tepals in C. sativus), explains the homeotic transformation of sepals into outer whorl tepals in this species. Analysis of PI/GLO sequences from C. sativus for putative targets to known micro-RNAs (miRNAs) showed that the target site for ath-miRNA167 found in Arabidopsis thaliana PI is not present in C. sativus, however, the PI/GLO sequences may be regulated by an ath-miRNA163. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
27. The maize alternative oxidase 1a (Aox1a) gene is regulated by signals related to oxidative stress.
- Author
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Polidoros, Alexios N., Mylona, Photini V., Pasentsis, Konstantinos, Scandalios, John G., and Tsaftaris, Athanasios S.
- Subjects
CORN ,OXIDASES ,INTRONS ,HYDROGEN peroxide ,NITRIC oxide - Abstract
We isolated and characterized the expression of Aox1a, a member of the maize alternative oxidase (Aox) small multigene family. Aox1a consists of four exons interrupted by three introns and its promoter harbors diverse stress-specific putative regulatory motifs pointing to complex regulation and response to multiple signals. Responses of Aox1a to such signals were examined and compared with those of maize glutathione S-transferase I (GstI), a typical oxidative stress inducible gene. Potassium cyanide (KCN) and hydrogen peroxide (H
2 O2 ) induced a rapid increase of the Aox1a and GstI transcripts, which was persisted in prolonged treatment at high H2 O2 concentration only for Aox1a. High concentration of salicylic acid (SA) and salicyl hydroxamic acid (SHAM) induced Aox1a mRNA only after prolonged exposure, while GstI displayed an early strong induction, which declined thereafter. Nitric oxide (NO) induced a high increase of Aox1a after prolonged exposure at high concentration, while GstI displayed a weak response. Our results show that multiple signaling pathways, involved in stress responses, also participate and differentially regulate Aox1a and GstI in maize. A ROS-depended signaling event may be involved, suggesting an essential role of Aox1a under oxidative stress in maize. [ABSTRACT FROM AUTHOR]- Published
- 2005
- Full Text
- View/download PDF
28. Isolation of a dehydrin cDNA from orange and grapefruit citrus fruit that is specifically induced by the combination of heat followed by chilling temperatures.
- Author
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Porat, Ron, Pasentsis, Konstantinos, Rozentvieg, Dafna, Gerasopoulos, Dimitrios, Falara, Vasiliki, Samach, Alon, Lurie, Susan, and Kanellis, Angelos K.
- Subjects
- *
PLANT proteins , *ENVIRONMENTAL engineering , *SOMATIC embryogenesis , *CITRUS , *GYMNOSPERMS , *POLYMERASE chain reaction - Abstract
Dehydrins (DHNs; late embryogenesis abundant D-11) are a family of plant proteins induced in response to environmental stresses such as water stress, salinity and freezing or which occur during the late stages of embryogenesis. Previously, it was reported that citrus contains a small gene family encoding a unique class of dehydrins that differs from most other plant dehydrins in various respects, such as having an unusual K-segment similar to that of gymnosperms. In the present study, we identified by cDNA differential display analysis a ‘Navel’ orange 202-bp polymerase chain reaction (PCR) fragment, which encoded the typical plant angiosperm-type K-segment consensus sequence, and of which the expression was down-regulated by exposure to low oxygen levels. The full-length cDNA sequence of the orange DHN, designated csDHN (for Citrus sinensis DHN), was further isolated by 5′-and 3′-RACE; it had a total length of 933 bp and encoded a predicted polypeptide of 235 amino acids. In addition, the same 202-bp ‘Navel’ dehydrin PCR fragment was used to screen a ‘Star Ruby’ grapefruit flavedo cDNA library, and its full-length grapefruit homologue, designated cpDHN (for C. paradisi DHN) was isolated and found to have a total length of 1024 bp and to encode a predicted polypeptide of 234 amino acids. The defined orange and grapefruit DHN proteins were completely identical in the 196 amino acids of their N-terminus but differed in their C-terminus region. Overall, the csDHN and cpDHN proteins share 84% identity and contain the conserved dehydrin serine cluster (S-segment) and a putative nuclear localization signal, but csDHN has one conserved dehydrin K-segment consensus sequence, whereas cpDHN contains two dehydrin K-segments. Both csDHN and cpDHN represent single copy genes, in ‘Navel’ orange and ‘Star Ruby’ grapefruit genomes, respectively. We found that the cpDHN gene was consistently expressed in the fruit peel tissue at harvest, but that its message levels dramatically decreased during storage at either ambient or low temperatures. However, a pre-storage hot water treatment, given to enhance fruit-chilling tolerance, increased cpDHN mRNA levels during the first 3 weeks of cold storage at 2°C, and enabled the message levels to be retained for up to a further 8 weeks of cold storage at 2°C. The hot water treatment by itself had no inductive effect on cpDHN gene expression when the fruits were held at non-chilling temperatures. Other stresses applied to the fruit, such as wounding, UV irradiation, water stress, low oxygen and exposure to the stress hormone ethylene decreased DHN mRNA levels, whereas abscisic acid had no effect at all. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
29. Microbial profiles of Greek PDO cheeses assessed with amplicon metabarcoding.
- Author
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Michailidou, Sofia, Pavlou, Eleftherios, Pasentsis, Konstantinos, Rhoades, Jonathan, Likotrafiti, Eleni, and Argiriou, Anagnostis
- Subjects
- *
CHEESE products , *CHEESE , *GENETIC barcoding , *LACTIC acid bacteria , *BACTERIAL population , *MICROBIAL communities , *PROKARYOTES - Abstract
Greece is a country possessing many cheese products granted with a PDO (Protected Designation of Origin) certificate, with high exporting activities. In this study, we analyzed six popular cheese PDO products purchased from different industries to assess their microbial communities using amplicon metabarcoding analysis. To this end, using Next Generation Sequencing technology, we sequenced the 16S rRNA gene and the ITS spacer for prokaryotes and fungi, respectively. Alpha diversity indices revealed higher bacterial species richness for some cheeses (Kopanisti, Batzos) and poor for others (Feta, Galotiri). Kopanisti, together with Kalathaki and Anevato, also presented increased species diversity concerning fungal populations. Results showed that lactic acid bacteria (LAB) prevailed the bacterial populations in all samples (Lactococcus , Lactobacillus , Streptococcus , Leuconostoc), whereas for fungi, members of the Saccharomycetaceae, Dipodascaceae and Debaryomycetaceae families prevailed the fungal populations. Several other genera were identified that make up each product's microbiome leading to the creation of the unique organoleptic attributes of Greek PDO cheeses. However, the identified species could not be directly linked to certain cheese types, assuming that starter and adjunct cultures, combined with the raw material used during production greatly impact the microbial communities in cheeses. Our data, produced for the first time for six Greek PDO cheeses, can be exploited in the process of creating a core microbial signature within each cheese type, supporting the Greek brand name and valorizing cheese products. • Microbial analysis of six different Greek PDO cheeses (16S rRNA gene and ITS region). • Assessment of microbiota using amplicon metabarcoding approach. • Lactococcus , Lactobacillus , Streptococcus , Leuconostoc prevailed bacterial populations. • Debaryomyces , Kluyveromyces and Kazachstania were the dominant fungi. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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30. Implementation of HPV-based Cervical Cancer Screening Combined with Self-sampling Using a Midwifery Network Across Rural Greece: The GRECOSELF Study.
- Author
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Agorastos T, Chatzistamatiou K, Tsertanidou A, Mouchtaropoulou E, Pasentsis K, Kitsou A, Moysiadis T, Moschaki V, Skenderi A, Katsiki E, Aggelidou S, Venizelos I, Ntoula M, Daponte A, Vanakara P, Garas A, Stefos T, Vrekoussis T, Lymberis V, Kontomanolis EN, Makrigiannakis A, Manidakis G, Deligeoroglou E, Panoskaltsis T, Decavalas GO, Michail G, Kalogiannidis I, Koukoulis G, Zempili P, Halatsi D, Truva T, Piha V, Agelena G, Chronopoulou A, Vaitsi V, Chatzaki E, Paschopoulos M, Adonakis G, Kaufmann AM, Hadzidimitriou A, and Stamatopoulos K
- Subjects
- Adolescent, Adult, Aged, Colposcopy statistics & numerical data, Community Networks organization & administration, Community Networks standards, Cross-Sectional Studies, DNA, Viral analysis, DNA, Viral genetics, Diagnostic Self Evaluation, Early Detection of Cancer methods, Early Detection of Cancer standards, Early Detection of Cancer statistics & numerical data, Female, Greece epidemiology, Humans, Implementation Science, Mass Screening methods, Mass Screening standards, Middle Aged, Midwifery methods, Nurse Midwives organization & administration, Nurse Midwives standards, Nurse Midwives statistics & numerical data, Nurse's Role, Papillomaviridae genetics, Papillomaviridae isolation & purification, Papillomavirus Infections complications, Papillomavirus Infections epidemiology, Papillomavirus Infections pathology, Rural Population statistics & numerical data, Specimen Handling standards, Specimen Handling statistics & numerical data, Uterine Cervical Neoplasms epidemiology, Uterine Cervical Neoplasms etiology, Vaginal Smears methods, Vaginal Smears statistics & numerical data, Young Adult, Uterine Cervical Dysplasia epidemiology, Uterine Cervical Dysplasia etiology, Human Papillomavirus DNA Tests methods, Human Papillomavirus DNA Tests standards, Human Papillomavirus DNA Tests statistics & numerical data, Mass Screening organization & administration, Midwifery organization & administration, Papillomavirus Infections diagnosis, Specimen Handling methods, Uterine Cervical Neoplasms diagnosis, Uterine Cervical Dysplasia diagnosis
- Abstract
Self-sampling for human papillomavirus (HPV) testing is an alternative to physician sampling particularly for cervical cancer screening nonattenders. The GRECOSELF study is a nationwide observational cross-sectional study aiming to suggest a way to implement HPV-DNA testing in conjunction with self-sampling for cervical cancer screening in Greece, utilizing a midwifery network. Women residing in remote areas of Greece were approached by midwives, of a nationwide network, and were provided with a self-collection kit (dry swab) for cervicovaginal sampling and asked to answer a questionnaire about their cervical cancer screening history. Each sample was tested for high-risk (hr) HPV with the Cobas HPV test. HrHPV-Positive women were referred to undergo colposcopy and, if needed, treatment according to colposcopy/biopsy results. Between May 2016 and November 2018, 13,111 women were recruited. Of these, 12,787 women gave valid answers in the study questionnaire and had valid HPV-DNA results; hrHPV prevalence was 8.3%; high-grade cervical/vaginal disease or cancer prevalence was 0.6%. HrHPV positivity rate decreased with age from 20.7% for women aged 25-29 years to 5.1% for women aged 50-60 years. Positive predictive value for hrHPV testing and for HPV16/18 genotyping ranged from 5.0% to 11.6% and from 11.8% to 27.0%, respectively, in different age groups. Compliance to colposcopy referral rate ranged from 68.6% (for women 25-29) to 76.3% (for women 40-49). For women residing in remote areas of Greece, the detection of hrHPV DNA with the Cobas HPV test, on self-collected cervicovaginal samples using dry cotton swabs, which are provided by visiting midwives, is a promising method for cervical cancer secondary prevention., (©2019 American Association for Cancer Research.)
- Published
- 2019
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31. Rolling circle amplification-RACE: a method for simultaneous isolation of 5' and 3' cDNA ends from amplified cDNA templates.
- Author
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Polidoros AN, Pasentsis K, and Tsaftaris AS
- Subjects
- Cloning, Molecular, DNA Primers, Genes, Plant, Polymerase Chain Reaction instrumentation, Zea mays genetics, DNA, Complementary genetics, DNA, Complementary metabolism, Genetic Techniques, Nucleic Acid Amplification Techniques, Polymerase Chain Reaction methods
- Published
- 2006
- Full Text
- View/download PDF
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