47 research outputs found

    Hemotin, a regulator of phagocytosis encoded by a small ORF and xonserved across metazoans

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    Translation of hundreds of small ORFs (smORFs) of less than 100 amino acids has recently been revealed in vertebrates and Drosophila. Some of these peptides have essential and conserved cellular functions. In Drosophila, we have predicted a particular smORF class encoding ~80 aa hydrophobic peptides, which may function in membranes and cell organelles. Here, we characterise hemotin, a gene encoding an 88aa transmembrane smORF peptide localised to early endosomes in Drosophila macrophages. hemotin regulates endosomal maturation during phagocytosis by repressing the cooperation of 14-3-3ζ with specific phosphatidylinositol (PI) enzymes. hemotin mutants accumulate undigested phagocytic material inside enlarged endo-lysosomes and as a result, hemotin mutants have reduced ability to fight bacteria, and hence, have severely reduced life span and resistance to infections. We identify Stannin, a peptide involved in organometallic toxicity, as the Hemotin functional homologue in vertebrates, showing that this novel regulator of phagocytic processing is widely conserved, emphasizing the significance of smORF peptides in cell biology and disease

    Epigenome-wide methylation and progression to high-grade cervical intraepithelial neoplasia (CIN2+): a prospective cohort study in the United States.

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    BACKGROUND: Methylation levels may be associated with and serve as markers to predict risk of progression of precancerous cervical lesions. We conducted an epigenome-wide association study (EWAS) of CpG methylation and progression to high-grade cervical intraepithelial neoplasia (CIN2 +) following an abnormal screening test. METHODS: A prospective US cohort of 289 colposcopy patients with normal or CIN1 enrollment histology was assessed. Baseline cervical sample DNA was analyzed using Illumina HumanMethylation 450K (n = 76) or EPIC 850K (n = 213) arrays. Participants returned at provider-recommended intervals and were followed up to 5 years via medical records. We assessed continuous CpG M values for 9 cervical cancer-associated genes and time-to-progression to CIN2+. We estimated CpG-specific time-to-event ratios (TTER) and hazard ratios using adjusted, interval-censored Weibull accelerated failure time models. We also conducted an exploratory EWAS to identify novel CpGs with false discovery rate (FDR) < 0.05. RESULTS: At enrollment, median age was 29.2 years; 64.0% were high-risk HPV-positive, and 54.3% were non-white. During follow-up (median 24.4 months), 15 participants progressed to CIN2+. Greater methylation levels were associated with a shorter time-to-CIN2+ for CADM1 cg03505501 (TTER = 0.28; 95%CI 0.12, 0.63; FDR = 0.03) and RARB Cluster 1 (TTER = 0.46; 95% CI 0.29, 0.71; FDR = 0.01). There was evidence of similar trends for DAPK1 cg14286732, PAX1 cg07213060, and PAX1 Cluster 1. The EWAS detected 336 novel progression-associated CpGs, including those located in CpG islands associated with genes FGF22, TOX, COL18A1, GPM6A, XAB2, TIMP2, GSPT1, NR4A2, and APBB1IP. CONCLUSIONS: Using prospective time-to-event data, we detected associations between CADM1-, DAPK1-, PAX1-, and RARB-related CpGs and cervical disease progression, and we identified novel progression-associated CpGs. IMPACT: Methylation levels at novel CpG sites may help identify individuals with ≤CIN1 histology at higher risk of progression to CIN2+ and inform risk-based cervical cancer screening guidelines

    Classification and function of small open reading frames

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    Small open reading frames (smORFs) of 100 codons or fewer are usually - if arbitrarily - excluded from proteome annotations. Despite this, the genomes of many metazoans, including humans, contain millions of smORFs, some of which fulfil key physiological functions. Recently, the transcriptome of Drosophila melanogaster was shown to contain thousands of smORFs of different classes that actively undergo translation, which produces peptides of mostly unknown function. Here, we present a comprehensive analysis of smORFs in flies, mice and humans. We propose the existence of several functional classes of smORFs, ranging from inert DNA sequences to transcribed and translated cis-regulators of translation and peptides with a propensity to function as regulators of membrane-associated proteins, or as components of ancient protein complexes in the cytoplasm. We suggest that the different smORF classes could represent steps in gene, peptide and protein evolution. Our analysis introduces a distinction between different peptide-coding classes of smORFs in animal genomes, and highlights the role of model organisms for the study of small peptide biology in the context of development, physiology and human disease

    Paternal mtDNA and Maleness Are Co-Inherited but Not Causally Linked in Mytilid Mussels

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    BACKGROUND: In marine mussels of the genus Mytilus there are two mitochondrial genomes. One is transmitted through the female parent, which is the normal transmission route in animals, and the other is transmitted through the male parent which is an unusual phenomenon. In males the germ cell line is dominated by the paternal mitochondrial genome and the somatic cell line by the maternal. Research to date has not allowed a clear answer to the question of whether inheritance of the paternal genome is causally related to maleness. METHODOLOGY/PRINCIPAL FINDINGS: Here we present results from hybrid crosses, from triploid mussels and from observations of sperm mitochondria in fertilized eggs which clearly show that maleness and presence of the paternal mitochondrial genome can be decoupled. These same results show that the female mussel has exclusive control of whether her progeny will inherit the mitochondrial genome of the male parent. CONCLUSIONS/SIGNIFICANCE: These findings are important in our efforts to understand the mechanistic basis of this unusual mode of mitochondrial DNA inheritance that is common among bivalves

    Distinctive mitochondrial genome of Calanoid copepod Calanus sinicus with multiple large non-coding regions and reshuffled gene order: Useful molecular markers for phylogenetic and population studies

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    <p>Abstract</p> <p>Background</p> <p>Copepods are highly diverse and abundant, resulting in extensive ecological radiation in marine ecosystems. <it>Calanus sinicus </it>dominates continental shelf waters in the northwest Pacific Ocean and plays an important role in the local ecosystem by linking primary production to higher trophic levels. A lack of effective molecular markers has hindered phylogenetic and population genetic studies concerning copepods. As they are genome-level informative, mitochondrial DNA sequences can be used as markers for population genetic studies and phylogenetic studies.</p> <p>Results</p> <p>The mitochondrial genome of <it>C. sinicus </it>is distinct from other arthropods owing to the concurrence of multiple non-coding regions and a reshuffled gene arrangement. Further particularities in the mitogenome of <it>C. sinicus </it>include low A + T-content, symmetrical nucleotide composition between strands, abbreviated stop codons for several PCGs and extended lengths of the genes <it>atp6 </it>and <it>atp8 </it>relative to other copepods. The monophyletic Copepoda should be placed within the Vericrustacea. The close affinity between Cyclopoida and Poecilostomatoida suggests reassigning the latter as subordinate to the former. Monophyly of Maxillopoda is rejected. Within the alignment of 11 <it>C. sinicus </it>mitogenomes, there are 397 variable sites harbouring three 'hotspot' variable sites and three microsatellite loci.</p> <p>Conclusion</p> <p>The occurrence of the <it>circular subgenomic fragment </it>during laboratory assays suggests that special caution should be taken when sequencing mitogenomes using long PCR. Such a phenomenon may provide additional evidence of mitochondrial DNA recombination, which appears to have been a prerequisite for shaping the present mitochondrial profile of <it>C. sinicus </it>during its evolution. The lack of synapomorphic gene arrangements among copepods has cast doubt on the utility of gene order as a useful molecular marker for deep phylogenetic analysis. However, mitochondrial genomic sequences have been valuable markers for resolving phylogenetic issues concerning copepods. The variable site maps of <it>C. sinicus </it>mitogenomes provide a solid foundation for population genetic studies.</p

    Footprints of worldwide adaptation in structured populations of Drosophila melanogaster through the expanded DEST 2.0 genomic resource

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    Funding: M.Kap. was supported by the Horizon Europe project FAIRiCUBE (grant #101059238). S.S. was supported by the Horizon Europe project FAIRiCUBE (grant #101059238). D.O. was supported by the UK Biotechnology and Biological Sciences Research Council (BBSRC) grant BB/T007516/1. M.G.R. was supported by Natural Environment Research Council (NERC), UK award NE/V001566/1.Large-scale genomic resources can place genetic variation into an ecologically informed context. To advance our understanding of the population genetics of the fruit fly Drosophila melanogaster, we present an expanded release of the community-generated population genomics resource Drosophila Evolution over Space and Time (DEST 2.0; https://dest.bio/). This release includes 530 high-quality pooled libraries from flies collected across six continents over more than a decade (2009 to 2021), most at multiple time points per year; 211 of these libraries are sequenced and shared here for the first time. We used this enhanced resource to elucidate several aspects of the species' demographic history and identify novel signs of adaptation across spatial and temporal dimensions. For example, we showed that the spatial genetic structure of populations is stable over time, but that drift due to seasonal contractions of population size causes populations to diverge over time. We identified signals of adaptation that vary between continents in genomic regions associated with xenobiotic resistance, consistent with independent adaptation to common pesticides. Moreover, by analyzing samples collected during spring and fall across Europe, we provide new evidence for seasonal adaptation related to loci associated with pathogen response. Furthermore, we have also released an updated version of the DEST genome browser. This is a useful tool for studying spatiotemporal patterns of genetic variation in this classic model system.Peer reviewe

    Exploring the Link Between Obligate Anaerobe-Related Dysbiosis and Prostate Cancer Development: A Pilot Study.

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    BACKGROUND/OBJECTIVES: Several independent studies have associated prostate cancer (PCa) with specific groups of bacteria, most of them reporting the presence of anaerobic or microaerophilic species such as Cutibacterium acnes (C. acnes). Such findings suggest a prostate cancer-related bacterial dysbiosis, in a manner similar to the association between Helicobacter pylori infection and gastric cancer. In an earlier exploratory study looking for such dysbiosis events, using a culturomics approach, we discovered that the presence of obligate anaerobes (OAs) along with C. acnes was associated with increased prostate-specific antigen (PSA) levels in 39 participants. METHODS: Building on this, in this study, we analyzed 89 post-rectal examination urine samples, from men with prostate cancer attending the PROVENT trial, using 16S rDNA sequencing. Our investigation focused on the impact of six previously identified OA genera (Finegoldia, Fusobacterium, Prevotella, Peptoniphilus_A, Peptostreptococcus, and Veillonella_A) on PSA levels. However, an additional data-driven approach was followed to uncover more taxa linked to increased PSA. RESULTS: Our analysis revealed a statistically significant association between Peptostreptococcus and elevated PSA levels. Additionally, there were potential interactions between Prevotella and Fusobacterium. Interestingly, we also found that an aerobe, Ochrobactrum_A,was significantly linked to higher PSA levels. CONCLUSIONS: These findings suggest that OA-related dysbiosis may contribute to elevated PSA levels through prostate cell damage even before prostate cancer develops, possibly playing a role in chronic inflammation and the hypervascular changes seen in precancerous lesions. Future clinical trials with larger cohorts are needed to further evaluate the role of OA in prostate cancer development and progression

    Linking alpha-diversity estimates between community fingerprinting and high-throughput 16S rRNA gene amplicon sequencing

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    Question: Microbial diversity screening by means of high throughput 16S rRNA gene sequencing has become a gold standard procedure for examining changes in community composition and structure. However, a large amount of data on \u3b1-and \u3b2-diversity has been produced through community fingerprinting methods or 16S clone libraries. Recent studies have shown that \u3b2-diversity measured by community fingerprinting is comparable to the estimates through high-throughput 16S rRNA gene sequencing. However, no link is established between the \u3b1-diversity estimates of the two methodological categories yet. Methods: Here, we analyze a large set of data generated by high-throughput 16S rRNA gene sequencing from a variety of habitats, for which community fingerprinting, i.e. denaturant gradient gel electrophoresis (DGGE), terminal restriction fragment length polymorphism (T-RFLP) and clone library profiles are also available. We have used publicly available as well as experimentally- and in-silico-generated data accounting for more than 20 different habitats. Results: We observed a significant, positive correlation between richness estimates deduced from community fingerprinting methods and evenness estimates from high throughput 16S rRNA gene sequencing. Conclusions: Our results suggest that these two components of \u3b1-diversity are directly comparable. That enables the use of evenness estimates from a vast number of past studies for comparison to upcoming studies, as well as the use of community fingerprinting for accurate estimations of evenness. Our results also highlight the need for re-assessment of past studies that were based on richness estimates of low-resolution community fingerpinting method

    Epigenome-wide differential methylation and differential variability as predictors of high-grade cervical intraepithelial neoplasia (cin2+).

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    CpG site methylation patterns have potential to improve differentiation of high-grade screening-detected cervical abnormalities. We assessed CpG differential methylation (DM) and differential variability (DV) in high-grade (CIN2+) vs. low-grade (≤CIN1) lesions. In ≤CIN1 (n=117) and CIN2+ (n=31) samples, cervical sample DNA underwent testing with Illumina HumanMethylation arrays. We assessed DM and DV of CpG methylation M values among nine cervical cancer-associated genes. We fit CpG-specific linear models and estimated empirical Bayes standard errors and false discovery rates (FDR). An exploratory epigenome-wide association study (EWAS) aimed to detect novel DM and DV CpGs (FDR<0.05) and Gene Ontology (GO) term enrichment. Compared to ≤CIN1, CIN2+ exhibited greater methylation at CCNA1 Cluster 1 (M value difference 0.24; 95% CI 0.04, 0.43) and RARB Cluster 2 (0.16; 95% CI 0.05, 0.28), and lower methylation at CDH1 Cluster 1 (-0.15; 95% CI -0.26, -0.04). CIN2+ exhibited lower variability at CDH1 Cluster 2 (variation difference -0.24; 95% CI -0.41, -0.05) and FHIT Cluster 1 (-0.30; 95% CI -0.50, -0.09). EWAS detected 3,534 DM and 270 DV CpGs. Forty-four GO terms were enriched with DM CpGs related to transcriptional, structural, developmental, and neuronal processes. Methylation patterns may help triage screening-detected cervical abnormalities and inform US screening algorithms
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