40 research outputs found

    Excavations at Gournia, 2010-2012

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    This article presents previous research at Gournia, the overall goals of our project, a new plan of the settlement, and our 2010-2012 excavations in eight areas: the Pit House, the Northwest Area, the North Cemetery, North Trench, the Northeast Area, House Aa, several rooms in the palace, and House He. Analytical sections discuss the textual evidence; the painted plasters; and the botanical remains. Our excavations indicate that Gournia was first settled in the Final Neolithic period and grew into an industrial town by the Protopalatial period. Following a Middle Minoan II destruction, the town was reorganized in Middle Minoan IIIA to include the palace, which in Late Minoan IB employed Linear A

    The impact of maternal age on gene expression during the GV to MII transition in euploid human oocytes

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    STUDY QUESTION Are there age-related differences in gene expression during the germinal vesicle (GV) to metaphase II (MII) stage transition in euploid human oocytes? SUMMARY ANSWER A decrease in mitochondrial-related transcripts from GV to MII oocytes was observed, with a much greater reduction in MII oocytes with advanced age. WHAT IS KNOWN ALREADY Early embryonic development is dependent on maternal transcripts accumulated and stored within the oocyte during oogenesis. Transcriptional activity of the oocyte, which dictates its ultimate developmental potential, may be influenced by age and explain the reduced competence of advanced maternal age (AMA) oocytes compared with the young maternal age (YMA). Gene expression has been studied in human and animal oocytes; however, RNA sequencing could provide further insights into the transcriptome profiling of GV and in vivo matured MII euploid oocytes of YMA and AMA patients. STUDY DESIGN, SIZE, DURATION Fifteen women treated for infertility in a single IVF unit agreed to participate in this study. Five GV and 5 MII oocytes from 6, 21–26 years old women (YMA cohort) and 5 GV and 6 MII oocytes from 6, 41–44 years old women (AMA cohort) undergoing IVF treatment were donated. The samples were collected within a time frame of 4 months. RNA was isolated and deep sequenced at the single-cell level. All donors provided either GV or MII oocytes. PARTICIPANTS/MATERIALS, SETTING, METHODS Cumulus dissection from donated oocytes was performed 38 h after hCG injection, denuded oocytes were inserted into lysis buffer supplemented with RNase inhibitor. The samples were stored at −80°C until further use. Isolated RNA from GV and MII oocytes underwent library preparation using an oligo deoxy-thymidine (dT) priming approach (SMART-Seq v4 Ultra Low Input RNA assay; Takara Bio, Japan) and Nextera XT DNA library preparation assay (Illumina, USA) followed by deep sequencing. Data processing, quality assessment and bioinformatics analysis were performed using source-software, mainly including FastQC, HISAT2, StringTie and edgeR, along with functional annotation analysis, while scploid R package was employed to determine the ploidy status. MAIN RESULTS AND THE ROLE OF CHANCE Following deep sequencing of single GV and MII oocytes in both YMA and AMA cohorts, several hundred transcripts were found to be expressed at significantly different levels. When YMA and AMA MII oocyte transcriptomes were compared, the most significant of these were related to mitochondrial structure and function, including biological processes, mitochondrial respiratory chain complex I assembly and mitochondrial translational termination (false discovery rate (FDR) 6.0E−10 to 1.2E−7). These results indicate a higher energy potential of the YMA MII cohort that is reduced with ageing. Other biological processes that were significantly higher in the YMA MII cohort included transcripts involved in the translation process (FDR 1.9E−2). Lack of these transcripts could lead to inappropriate protein synthesis prior to or upon fertilisation of the AMA MII oocytes. LARGE SCALE DATA The RNA sequencing data were deposited in the Gene Expression Omnibus (https://www.ncbi.nlm.nih.gov/geo), under the accession number: GSE164371. LIMITATIONS, REASONS FOR CAUTION The relatively small sample size could be a reason for caution. However, the RNA sequencing results showed homogeneous clustering with low intra-group variation and five to six biological replicates derived from at least three different women per group minimised the potential impact of the sample size. WIDER IMPLICATIONS OF THE FINDINGS Understanding the effects of ageing on the oocyte transcriptome could highlight the mechanisms involved in GV to MII transition and identify biomarkers that characterise good MII oocyte quality. This knowledge has the potential to guide IVF regimes for AMA patients. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Medical Research Council (MRC Grant number MR/K020501/1)

    The Ascomycete Verticillium longisporum Is a Hybrid and a Plant Pathogen with an Expanded Host Range

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    Hybridization plays a central role in plant evolution, but its overall importance in fungi is unknown. New plant pathogens are thought to arise by hybridization between formerly separated fungal species. Evolution of hybrid plant pathogens from non-pathogenic ancestors in the fungal-like protist Phytophthora has been demonstrated, but in fungi, the most important group of plant pathogens, there are few well-characterized examples of hybrids. We focused our attention on the hybrid and plant pathogen Verticillium longisporum, the causal agent of the Verticillium wilt disease in crucifer crops. In order to address questions related to the evolutionary origin of V. longisporum, we used phylogenetic analyses of seven nuclear loci and a dataset of 203 isolates of V. longisporum, V. dahliae and related species. We confirmed that V. longisporum was diploid, and originated three different times, involving four different lineages and three different parental species. All hybrids shared a common parent, species A1, that hybridized respectively with species D1, V. dahliae lineage D2 and V. dahliae lineage D3, to give rise to three different lineages of V. longisporum. Species A1 and species D1 constituted as yet unknown taxa. Verticillium longisporum likely originated recently, as each V. longisporum lineage was genetically homogenous, and comprised species A1 alleles that were identical across lineages

    LTR Retrotransposons in Fungi

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    Transposable elements with long terminal direct repeats (LTR TEs) are one of the best studied groups of mobile elements. They are ubiquitous elements present in almost all eukaryotic genomes. Their number and state of conservation can be a highlight of genome dynamics. We searched all published fungal genomes for LTR-containing retrotransposons, including both complete, functional elements and remnant copies. We identified a total of over 66,000 elements, all of which belong to the Ty1/Copia or Ty3/Gypsy superfamilies. Most of the detected Gypsy elements represent Chromoviridae, i.e. they carry a chromodomain in the pol ORF. We analyzed our data from a genome-ecology perspective, looking at the abundance of various types of LTR TEs in individual genomes and at the highest-copy element from each genome. The TE content is very variable among the analyzed genomes. Some genomes are very scarce in LTR TEs (<50 elements), others demonstrate huge expansions (>8000 elements). The data shows that transposon expansions in fungi usually involve an increase both in the copy number of individual elements and in the number of element types. The majority of the highest-copy TEs from all genomes are Ty3/Gypsy transposons. Phylogenetic analysis of these elements suggests that TE expansions have appeared independently of each other, in distant genomes and at different taxonomical levels. We also analyzed the evolutionary relationships between protein domains encoded by the transposon pol ORF and we found that the protease is the fastest evolving domain whereas reverse transcriptase and RNase H evolve much slower and in correlation with each other

    Glucocorticoid and Estrogen Receptors Are Reduced in Mitochondria of Lung Epithelial Cells in Asthma

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    Mitochondrial glucocorticoid (mtGR) and estrogen (mtER) receptors participate in the coordination of the cell’s energy requirement and in the mitochondrial oxidative phosphorylation enzyme (OXPHOS) biosynthesis, affecting reactive oxygen species (ROS) generation and induction of apoptosis. Although activation of mtGR and mtER is known to trigger anti-inflammatory signals, little information exists on the presence of these receptors in lung tissue and their role in respiratory physiology and disease. Using a mouse model of allergic airway inflammation disease and applying confocal microscopy, subcellular fractionation, and Western blot analysis we showed mitochondrial localization of GRα and ERβ in lung tissue. Allergic airway inflammation caused reduction in mtGRα, mtERβ, and OXPHOS enzyme biosynthesis in lung cells mitochondria and particularly in bronchial epithelial cells mitochondria, which was accompanied by decrease in lung mitochondrial mass and induction of apoptosis. Confirmation and validation of the reduction of the mitochondrial receptors in lung epithelial cells in human asthma was achieved by analyzing autopsies from fatal asthma cases. The presence of the mitochondrial GRα and ERβ in lung tissue cells and especially their reduction in bronchial epithelial cells during allergic airway inflammation suggests a crucial role of these receptors in the regulation of mitochondrial function in asthma, implicating their involvement in the pathophysiology of the disease

    Reporting on the Role of miRNAs and Affected Pathways on the Molecular Backbone of Ovarian Insufficiency: A Systematic Review and Critical Analysis Mapping of Future Research

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    Ovarian insufficiency is identified as a perplexing entity in the long list of pathologies impairing fertility dynamics. The three distinct classifications of ovarian insufficiency are poor ovarian response, premature ovarian insufficiency/failure, and advanced maternal age, sharing the common denominator of deteriorated ovarian reserve. Despite efforts to define clear lines among the three, the vast heterogeneity and overlap of clinical characteristics renders their diagnosis and management challenging. Lack of a consensus has prompted an empirically based management coupled by uncertainty from the clinicians’ perspective. Profiling of patients in the era of precision medicine seems to be the way forward, while the necessity for a novel approach is underlined. Implicating miRNAs in the quest for patient profiling is promising in light of their fundamental role in cellular and gene expression regulation. To this end, the current study sets out to explore and compare the three pathophysiologies—from a molecular point of view—in order to enable profiling of patients in the context of in vitro fertilization treatment and enrich the data required to practice individualized medicine. Following a systematic investigation of literature, data referring to miRNAs were collected for each patient category based on five included studies. miRNA–target pairs were retrieved from the DIANA-TarBase repository and microT-CDS. Gene and miRNA annotations were derived from Ensembl and miRbase. A subsequent gene-set enrichment analysis of miRNA targets was performed for each category separately. A literature review on the most crucial of the detected pathways was performed to reveal their relevance to fertility deterioration. Results supported that all three pathophysiologies share a common ground regarding the affected pathways, naturally attributed to the common denominator of ovarian insufficiency. As evidenced, miRNAs could be employed to explore the fine lines and diverse nature of pathophysiology since they constitute invaluable biomarkers. Interestingly, it is the differentiation through miRNAs and not through the molecular affected pathways that corresponds to the three distinctive categories. Alarming discrepancies among publications were revealed, pertaining to employment of empirical and arbitrary criteria in categorizing the patients. Following bioinformatic analysis, the final step of the current study consisted of a critical analysis of the molecular data sourced, providing a clear and unique insight into the physiological mechanisms involved. It is our intention to contribute to mapping future research dedicated to ovarian insufficiency and to help researchers navigate the overwhelming information published in molecular studies. © Copyright © 2021 Rapani, Nikiforaki, Karagkouni, Sfakianoudis, Tsioulou, Grigoriadis, Maziotis, Pantou, Voutsina, Pantou, Koutsilieris, Hatzigeorgiou, Pantos and Simopoulou

    Reporting on the Role of miRNAs and Affected Pathways on the Molecular Backbone of Ovarian Insufficiency: A Systematic Review and Critical Analysis Mapping of Future Research

    No full text
    Ovarian insufficiency is identified as a perplexing entity in the long list of pathologies impairing fertility dynamics. The three distinct classifications of ovarian insufficiency are poor ovarian response, premature ovarian insufficiency/failure, and advanced maternal age, sharing the common denominator of deteriorated ovarian reserve. Despite efforts to define clear lines among the three, the vast heterogeneity and overlap of clinical characteristics renders their diagnosis and management challenging. Lack of a consensus has prompted an empirically based management coupled by uncertainty from the clinicians’ perspective. Profiling of patients in the era of precision medicine seems to be the way forward, while the necessity for a novel approach is underlined. Implicating miRNAs in the quest for patient profiling is promising in light of their fundamental role in cellular and gene expression regulation. To this end, the current study sets out to explore and compare the three pathophysiologies—from a molecular point of view—in order to enable profiling of patients in the context of in vitro fertilization treatment and enrich the data required to practice individualized medicine. Following a systematic investigation of literature, data referring to miRNAs were collected for each patient category based on five included studies. miRNA–target pairs were retrieved from the DIANA-TarBase repository and microT-CDS. Gene and miRNA annotations were derived from Ensembl and miRbase. A subsequent gene-set enrichment analysis of miRNA targets was performed for each category separately. A literature review on the most crucial of the detected pathways was performed to reveal their relevance to fertility deterioration. Results supported that all three pathophysiologies share a common ground regarding the affected pathways, naturally attributed to the common denominator of ovarian insufficiency. As evidenced, miRNAs could be employed to explore the fine lines and diverse nature of pathophysiology since they constitute invaluable biomarkers. Interestingly, it is the differentiation through miRNAs and not through the molecular affected pathways that corresponds to the three distinctive categories. Alarming discrepancies among publications were revealed, pertaining to employment of empirical and arbitrary criteria in categorizing the patients. Following bioinformatic analysis, the final step of the current study consisted of a critical analysis of the molecular data sourced, providing a clear and unique insight into the physiological mechanisms involved. It is our intention to contribute to mapping future research dedicated to ovarian insufficiency and to help researchers navigate the overwhelming information published in molecular studies. © Copyright © 2021 Rapani, Nikiforaki, Karagkouni, Sfakianoudis, Tsioulou, Grigoriadis, Maziotis, Pantou, Voutsina, Pantou, Koutsilieris, Hatzigeorgiou, Pantos and Simopoulou
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