Pseudogenes: are they "junk" or functional DNA?

Combining single-cell profiling and functional analysis explores the role of pseudogenes in human early embryonic development

More and more studies have demonstrated that pseudogenes possess coding ability, and the functions of their transcripts in the development of diseases have been partially revealed. However, the role of pseudogenes in maintenance of normal physiological states and life activities has long been neglected. Here, we identify pseudogenes that are dynamically expressed during human early embryogenesis, showing different expression pattern from that of adult tissues. We explore the expression correlation between pseudogenes and the parent genes, part due to their shared gene regulatory elements or the potential regulation network between them. The essential role of three pseudogenes, PI4KAP1, TMED10P1, and FBXW4P1, in maintaining self-renewal of human embryonic stem cells is demonstrated. We further find that the three pseudogenes might perform their regulatory functions by binding to proteins or microRNAs. The pseudogene-related single-nucleotide polymorphisms are significantly associated with human congenital disease, further illustrating their importance during early embryonic development. Overall, this study is an excavation and exploration of functional pseudogenes during early human embryonic development, suggesting that pseudogenes are not only capable of being specifically activated in pathological states, but also play crucial roles in the maintenance of normal physiological states.

Loss to gain: pseudogenes in microorganisms, focusing on eubacteria, and their biological significance

Pseudogenes are defined as "non-functional" copies of corresponding parent genes. The cognition of pseudogenes continues to be refreshed through accumulating and updating research findings. Previous studies have predominantly focused on mammals, but pseudogenes have received relatively less attention in the field of microbiology. Given the increasing recognition on the importance of pseudogenes, in this review, we focus on several aspects of microorganism pseudogenes, including their classification and characteristics, their generation and fate, their identification, their abundance and distribution, their impact on virulence, their ability to recombine with functional genes, the extent to which some pseudogenes are transcribed and translated, and the relationship between pseudogenes and viruses. By summarizing and organizing the latest research progress, this review will provide a comprehensive perspective and improved understanding on pseudogenes in microorganisms. KEY POINTS: • Concept, classification and characteristics, identification and databases, content, and distribution of microbial pseudogenes are presented. • How pseudogenization contribute to pathogen virulence is highlighted. • Pseudogenes with potential functions in microorganisms are discussed.

Origin and early divergence of tandem duplicated sorbitol transporter genes in Rosaceae: insights from evolutionary analysis of the SOT gene family in angiosperms

Sorbitol is a critical photosynthate and storage substance in the Rosaceae family. Sorbitol transporters (SOTs) play a vital role in facilitating sorbitol allocation from source to sink organs and sugar accumulation in sink organs. While prior research has addressed gene duplications within the SOT gene family in Rosaceae, the precise origin and evolutionary dynamics of these duplications remain unclear, largely due to the complicated interplay of whole genome duplications and tandem duplications. Here, we investigated the synteny relationships among all identified Polyol/Monosaccharide Transporter (PLT) genes in 61 angiosperm genomes and SOT genes in representative genomes within the Rosaceae family. By integrating phylogenetic analyses, we elucidated the lineage-specific expansion and syntenic conservation of PLTs and SOTs across diverse plant lineages. We found that Rosaceae SOTs, as PLT family members, originated from a pair of tandemly duplicated PLT genes within Class III-A. Furthermore, our investigation highlights the role of lineage-specific and synergistic duplications in Amygdaloideae in contributing to the expansion of SOTs in Rosaceae plants. Collectively, our findings provide insights into the genomic origins, duplication events, and subsequent divergence of SOT gene family members. Such insights lay a crucial foundation for comprehensive functional characterizations in future studies.

Microorganisms that produce enzymes active on biodegradable polyesters are ubiquitous

Biodegradability standards measure ultimate biodegradation of polymers by exposing the material under test to a natural microbial inoculum. Available tests developed by the International Organization for Standardization (ISO) use inoculums sampled from different environments e.g. soil, marine sediments, seawater. Understanding whether each inoculum is to be considered as microbially unique or not can be relevant for the interpretation of tests results. In this review, we address this question by consideration of the following: (i) the chemical nature of biodegradable plastics (virtually all biodegradable plastics are polyesters) (ii) the diffusion of ester bonds in nature both in simple molecules and in polymers (ubiquitous); (iii) the diffusion of decomposers capable of producing enzymes, called esterases, which accelerate the hydrolysis of esters, including polyesters (ubiquitous); (iv) the evidence showing that synthetic polyesters can be depolymerized by esterases (large and growing); (v) the evidence showing that these esterases are ubiquitous (growing and confirmed by bioinformatics studies). By combining the relevant available facts it can be concluded that if a certain polyester shows ultimate biodegradation when exposed to a natural inoculum, it can be considered biodegradable and need not be retested using other inoculums. Obviously, if the polymer does not show ultimate biodegradation it must be considered recalcitrant, until proven otherwise.

Individual and population diversity of 20 representative olfactory receptor genes in pigs

Understanding the influence of genetic variations in olfactory receptor (OR) genes on the olfaction-influenced phenotypes such as behaviors, reproduction, and feeding is important in animal biology. However, our understanding of the complexity of the OR subgenome is limited. In this study, we analyzed 1120 typing results of 20 representative OR genes belonging to 13 OR families on 14 pig chromosomes from 56 individuals belonging to seven different breeds using a sequence-based OR typing method. We showed that the presence of copy number variations, conservation of locus-specific diversity, abundance of breed-specific alleles, presence of a loss-of-function allele, and low-level purifying selection in pig OR genes could be common characteristics of OR genes in mammals. The observed nucleotide sequence diversity of pig ORs was higher than that of dogs. To the best of our knowledge, this is the first report on the individual- or population-level characterization of a large number of OR family genes in livestock species.

Unravelling the due importance of pseudogenes and their resurrection in plants

The complexities of a genome are underpinned to the vast expanses of the intergenic region, which constitutes ∼97-98% of the genome. This region is essentially composed of what is colloquially referred to as the "junk DNA" and is composed of various elements like transposons, repeats, pseudogenes, etc. The latter have long been considered as dead elements merely contributing to transcriptional noise in the genome. Many studies now describe the previously unknown regulatory functions of these genes. Recent advances in the Next-generation sequencing (NGS) technologies have allowed unprecedented access to these regions. With the availability of whole genome sequences of more than 788 different plant species in past 20 years, genome annotation has become feasible like never before. Different bioinformatic pipelines are available for the identification of pseudogenes. However, still little is known about their biological functions. The functional validation of these genes remains challenging and research in this area is still in infancy, particularly in plants. CRISPR/Cas-based genome editing could provide solutions to understand the biological roles of these genes by allowing creation of precise edits within these genes. The possibility of pseudogene reactivation or resurrection as has been demonstrated in a few studies might open new avenues of genetic manipulation to yield a desirable phenotype. This review aims at comprehensively summarizing the progress made with regards to the identification of pseudogenes and understanding their biological functions in plants.

Genome-wide identification of DUF506 gene family in Oryzasativa and expression profiling under abiotic stresses

The domain of unknown function 560 (DUF560), also known as the PDDEXK_6 family, is a ubiquitous plant protein that has been confirmed to play critical roles in Arabidopsis root development as well as ABA and abiotic responses. However, genome-wide identification and expression pattern analysis in rice (Oryza sativa) still need to be improved. Based on the phylogenetic relationship, 10 OsDUF506 genes were identified and classified into four subfamilies. Segmental duplication was essential to the expansion of OsDUF506s, which were subjected to purifying selective pressure. Except for OsDUF50609 and OsDUF50610, the OsDUF506s shared colinear gene pairs with five monocot species, showing that they were conserved in evolution. Furthermore, the conserved domains, gene structures, SNPs distribution, and targeting miRNAs were systematically investigated. Massive cis-regulatory elements were discovered in promoter regions, implying that OsDUF506s may be important in hormone regulation and abiotic stress response. Therefore, we analyzed plant hormone-induced transcriptome data and performed qRT-PCR on eight OsDUF506s under drought, cold, and phosphorus-deficient stresses. The results revealed that most OsDUF506s respond to ABA and JA treatment, as well as drought and cold conditions. In conclusion, our findings provided insights into the evolution and function of OsDUF506s, which could benefit crop breeding in the future.

A comprehensive review and evaluation of graph neural networks for non-coding RNA and complex disease associations

Non-coding RNAs (ncRNAs) play a critical role in the occurrence and development of numerous human diseases. Consequently, studying the associations between ncRNAs and diseases has garnered significant attention from researchers in recent years. Various computational methods have been proposed to explore ncRNA-disease relationships, with Graph Neural Network (GNN) emerging as a state-of-the-art approach for ncRNA-disease association prediction. In this survey, we present a comprehensive review of GNN-based models for ncRNA-disease associations. Firstly, we provide a detailed introduction to ncRNAs and GNNs. Next, we delve into the motivations behind adopting GNNs for predicting ncRNA-disease associations, focusing on data structure, high-order connectivity in graphs and sparse supervision signals. Subsequently, we analyze the challenges associated with using GNNs in predicting ncRNA-disease associations, covering graph construction, feature propagation and aggregation, and model optimization. We then present a detailed summary and performance evaluation of existing GNN-based models in the context of ncRNA-disease associations. Lastly, we explore potential future research directions in this rapidly evolving field. This survey serves as a valuable resource for researchers interested in leveraging GNNs to uncover the complex relationships between ncRNAs and diseases.

Constructing Integrative ceRNA Networks and Finding Prognostic Biomarkers in Renal Cell Carcinoma

Inspired by a newly discovered gene regulation mechanism known as competing endogenous RNA (ceRNA) interactions, several computational methods have been proposed to generate ceRNA networks. However, most of these methods have focused on deriving restricted types of ceRNA interactions such as lncRNA-miRNA-mRNA interactions. Competition for miRNA-binding occurs not only between lncRNAs and mRNAs but also between lncRNAs or between mRNAs. Furthermore, a large number of pseudogenes also act as ceRNAs, thereby regulate other genes. In this study, we developed a general method for constructing integrative networks of all possible interactions of ceRNAs in renal cell carcinoma (RCC). From the ceRNA networks we derived potential prognostic biomarkers, each of which is a triplet of two ceRNAs and miRNA (i.e., ceRNA-miRNA-ceRNA). Interestingly, some prognostic ceRNA triplets do not include mRNA at all, and consist of two non-coding RNAs and miRNA, which have been rarely known so far. Comparison of the prognostic ceRNA triplets to known prognostic genes in RCC showed that the triplets have a better predictive power of survival rates than the known prognostic genes. Our approach will help us construct integrative networks of ceRNAs of all types and find new potential prognostic biomarkers in cancer.

The non-coding competing endogenous RNAs in acute myeloid leukemia: biological and clinical implications

Acute myeloid leukemia (AML) is a hematologic carcinoma that has seen a considerable improvement in patient prognosis because of genetic diagnostics and molecularly-targeted therapies. Nevertheless, recurrence and drug resistance remain significant obstacles to leukemia treatment. It is critical to investigate the underlying molecular mechanisms and find solutions. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), circular RNAs, long non-coding RNAs, and pseudogenes, have been found to be crucial components in driving cancer. The competing endogenous RNA (ceRNA) mechanism has expanded the complexity of miRNA-mediated gene regulation. A great deal of literature has shown that ncRNAs are essential to the biological functions of the ceRNA network (ceRNET). NcRNAs can compete for the same miRNA response elements to influence miRNA-target RNA interactions. Recent evidence suggests that ceRNA might be a potential biomarker and therapeutic strategy. So far, however, there have been no comprehensive studies on ceRNET about AML. What is not yet clear is the clinical application of ceRNA in AML. This study attempts to summarize the development of research on the related ceRNAs in AML and the roles of ncRNAs in ceRNET. We also briefly describe the mechanisms of ceRNA and ceRNET. What's more significant is that we explore the clinical value of ceRNAs to provide accurate diagnostic and prognostic biomarkers as well as therapeutic targets. Finally, limitations and prospects are considered.

Reduction of Paraoxonase Expression Followed by Inactivation across Independent Semiaquatic Mammals Suggests Stepwise Path to Pseudogenization

Convergent adaptation to the same environment by multiple lineages frequently involves rapid evolutionary change at the same genes, implicating these genes as important for environmental adaptation. Such adaptive molecular changes may yield either change or loss of protein function; loss of function can eliminate newly deleterious proteins or reduce energy necessary for protein production. We previously found a striking case of recurrent pseudogenization of the Paraoxonase 1 (Pon1) gene among aquatic mammal lineages-Pon1 became a pseudogene with genetic lesions, such as stop codons and frameshifts, at least four times independently in aquatic and semiaquatic mammals. Here, we assess the landscape and pace of pseudogenization by studying Pon1 sequences, expression levels, and enzymatic activity across four aquatic and semiaquatic mammal lineages: pinnipeds, cetaceans, otters, and beavers. We observe in beavers and pinnipeds an unexpected reduction in expression of Pon3, a paralog with similar expression patterns but different substrate preferences. Ultimately, in all lineages with aquatic/semiaquatic members, we find that preceding any coding-level pseudogenization events in Pon1, there is a drastic decrease in expression, followed by relaxed selection, thus allowing accumulation of disrupting mutations. The recurrent loss of Pon1 function in aquatic/semiaquatic lineages is consistent with a benefit to Pon1 functional loss in aquatic environments. Accordingly, we examine diving and dietary traits across pinniped species as potential driving forces of Pon1 functional loss. We find that loss is best associated with diving activity and likely results from changes in selective pressures associated with hypoxia and hypoxia-induced inflammation.

The X-factor in ART: does the use of assisted reproductive technologies influence DNA methylation on the X chromosome?

BACKGROUND

Assisted reproductive technologies (ART) may perturb DNA methylation (DNAm) in early embryonic development. Although a handful of epigenome-wide association studies of ART have been published, none have investigated CpGs on the X chromosome. To bridge this knowledge gap, we leveraged one of the largest collections of mother-father-newborn trios of ART and non-ART (natural) conceptions to date to investigate sex-specific DNAm differences on the X chromosome. The discovery cohort consisted of 982 ART and 963 non-ART trios from the Norwegian Mother, Father, and Child Cohort Study (MoBa). To verify our results from the MoBa cohort, we used an external cohort of 149 ART and 58 non-ART neonates from the Australian 'Clinical review of the Health of adults conceived following Assisted Reproductive Technologies' (CHART) study. The Illumina EPIC array was used to measure DNAm in both datasets. In the MoBa cohort, we performed a set of X-chromosome-wide association studies ('XWASs' hereafter) to search for sex-specific DNAm differences between ART and non-ART newborns. We tested several models to investigate the influence of various confounders, including parental DNAm. We also searched for differentially methylated regions (DMRs) and regions of co-methylation flanking the most significant CpGs. Additionally, we ran an analogous model to our main model on the external CHART dataset.

RESULTS

In the MoBa cohort, we found more differentially methylated CpGs and DMRs in girls than boys. Most of the associations persisted after controlling for parental DNAm and other confounders. Many of the significant CpGs and DMRs were in gene-promoter regions, and several of the genes linked to these CpGs are expressed in tissues relevant for both ART and sex (testis, placenta, and fallopian tube). We found no support for parental DNAm-dependent features as an explanation for the observed associations in the newborns. The most significant CpG in the boys-only analysis was in UBE2DNL, which is expressed in testes but with unknown function. The most significant CpGs in the girls-only analysis were in EIF2S3 and AMOT. These three loci also displayed differential DNAm in the CHART cohort.

CONCLUSIONS

Genes that co-localized with the significant CpGs and DMRs associated with ART are implicated in several key biological processes (e.g., neurodevelopment) and disorders (e.g., intellectual disability and autism). These connections are particularly compelling in light of previous findings indicating that neurodevelopmental outcomes differ in ART-conceived children compared to those naturally conceived.

Astrocytes express aberrant immunoglobulins as putative gatekeeper of astrocytes to neuronal progenitor conversion

Using multi-omics analyses including RNAseq, RT-PCR, RACE-PCR, and shotgun proteomic with enrichment strategies, we demonstrated that newborn rat astrocytes produce neural immunoglobulin constant and variable heavy chains as well as light chains. However, their edification is different from the ones found in B cells and they resemble aberrant immunoglobulins observed in several cancers. Moreover, the complete enzymatic V(D)J recombination complex has also been identified in astrocytes. In addition, the constant heavy chain is also present in adult rat astrocytes, whereas in primary astrocytes from human fetus we identified constant and variable kappa chains as well as the substitution lambda chains known to be involved in pre-B cells. To gather insights into the function of these neural IgGs, CRISPR-Cas9 of IgG2B constant heavy chain encoding gene (Igh6), IgG2B overexpression, proximal labeling of rat astrocytes IgG2B and targets identification through 2D gels were performed. In Igh6 KO astrocytes, overrepresentation of factors involved in hematopoietic cells, neural stem cells, and the regulation of neuritogenesis have been identified. Moreover, overexpression of IgG2B in astrocytes induces the CRTC1-CREB-BDNF signaling pathway known to be involved in gliogenesis, whereas Igh6 KO triggers the BMP/YAP1/TEAD3 pathway activated in astrocytes dedifferentiation into neural progenitors. Proximal labeling experiments revealed that IgG2B is N-glycosylated by the OST complex, addressed to vesicle membranes containing the ATPase complex, and behaves partially like CD98hc through its association with LAT1. These experiments also suggest that proximal IgG2B-LAT1 interaction occurs concomitantly with MACO-1 and C2CD2L, at the heart of a potentially novel cell signaling platform. Finally, we demonstrated that these chains are synthesized individually and associated to recognize specific targets. Indeed, intermediate filaments Eif4a2 and Pdia6 involved in astrocyte fate constitute targets for these neural IgGs. Taken together, we hypothese that neural aberrant IgG chains may act as gatekeepers of astrocytes' fate.

Evolutionary differences in gene loss and pseudogenization among mycoheterotrophic orchids in the tribe Vanilleae (subfamily Vanilloideae)

INTRODUCTION

Galeola lindleyana is a mycoheterotrophic orchid belonging to the tribe Vanilleae within the subfamily Vanilloideae.

METHODS

In this study, the G. lindleyana plastome was assembled and annotated, and compared with other Vanilleae orchids, revealing the evolutionary variations between the photoautotrophic and mycoheterotrophic plastomes.

RESULTS

The G. lindleyana plastome was found to include 32 protein-coding genes, 16 tRNA genes and four ribosomal RNA genes, including 11 pseudogenes. Almost all of the genes encoding photosynthesis have been lost physically or functionally, with the exception of six genes encoding ATP synthase and psaJ in photosystem I. The length of the G. lindleyana plastome has decreased to 100,749 bp, while still retaining its typical quadripartite structure. Compared with the photoautotrophic Vanilloideae plastomes, the inverted repeat (IR) regions and the large single copy (LSC) region of the mycoheterotrophic orchid's plastome have contracted, while the small single copy (SSC) region has expanded significantly. Moreover, the difference in length between the two ndhB genes was found to be 682 bp, with one of them spanning the IRb/SSC boundary. The Vanilloideae plastomes were varied in their structural organization, gene arrangement, and gene content. Even the Cyrtosia septentrionalis plastome which was found to be closest in length to the G. lindleyana plastome, differed in terms of its gene arrangement and gene content. In the LSC region, the psbA, psbK, atpA and psaB retained in the G. lindleyana plastome were missing in the C. septentrionalis plastome, while, the matK, rps16, and atpF were incomplete in the C. septentrionalis plastome, yet still complete in that of the G. lindleyana. Lastly, compared with the G. lindleyana plastome, a 15 kb region located in the SSC area between ndhB-rrn16S was found to be inverted in the C. septentrionalis plastome. These changes in gene content, gene arrangment and gene structure shed light on the polyphyletic evolution of photoautotrophic orchid plastomes to mycoheterotrophic orchid plastomes.

DISCUSSION

Thus, this study's decoding of the mycoheterotrophic G. lindleyana plastome provides valuable resource data for future research and conservation of endangered orchids.

Polystyrene nanoplastics affect transcriptomic and epigenomic signatures of human fibroblasts and derived induced pluripotent stem cells: Implications for human health

Plastic pollution is increasing at an alarming rate yet the impact of this pollution on human health is poorly understood. Because human induced pluripotent stem cells (hiPSC) are frequently derived from dermal fibroblasts, these cells offer a powerful platform for the identification of molecular biomarkers of environmental pollution in human cells. Here, we describe a novel proof-of-concept for deriving hiPSC from human dermal fibroblasts deliberately exposed to polystyrene (PS) nanoplastic particles; unexposed hiPSC served as controls. In parallel, unexposed hiPSC were exposed to low and high concentrations of PS nanoparticles. Transcriptomic and epigenomic signatures of all fibroblasts and hiPSCs were defined using RNA-seq and whole genome methyl-seq, respectively. Both PS-treated fibroblasts and derived hiPSC showed alterations in expression of ESRRB and HNF1A genes and circuits involved in the pluripotency of stem cells, as well as in pathways involved in cancer, inflammatory disorders, gluconeogenesis, carbohydrate metabolism, innate immunity, and dopaminergic synapse. Similarly, the expression levels of identified key transcriptional and DNA methylation changes (DNMT3A, ESSRB, FAM133CP, HNF1A, SEPTIN7P8, and TTC34) were significantly affected in both PS-exposed fibroblasts and hiPSC. This study illustrates the power of human cellular models of environmental pollution to narrow down and prioritize the list of candidate molecular biomarkers of environmental pollution. This knowledge will facilitate the deciphering of the origins of environmental diseases.

Mitochondrial genomes in the iconic reindeer lichens: Architecture, variation, and synteny across multiple evolutionary scales

Variation in mitochondrial genome composition across intraspecific, interspecific, and higher taxonomic scales has been little studied in lichen obligate symbioses. Cladonia is one of the most diverse and ecologically important lichen genera, with over 500 species representing an array of unique morphologies and chemical profiles. Here, we assess mitochondrial genome diversity and variation in this flagship genus, with focused sampling of two clades of the "true" reindeer lichens, Cladonia subgenus Cladina, and additional genomes from nine outgroup taxa. We describe composition and architecture at the gene and the genome scale, examining patterns in organellar genome size in larger taxonomic groups in Ascomycota. Mitochondrial genomes of Cladonia, Pilophorus, and Stereocaulon were consistently larger than those of Lepraria and contained more introns, suggesting a selective pressure in asexual morphology in Lepraria driving it toward genomic simplification. Collectively, lichen mitochondrial genomes were larger than most other fungal life strategies, reaffirming the notion that coevolutionary streamlining does not correlate to genome size reductions. Genomes from Cladonia ravenelii and Stereocaulon pileatum exhibited ATP9 duplication, bearing paralogs that may still be functional. Homing endonuclease genes (HEGs), though scarce in Lepraria, were diverse and abundant in Cladonia, exhibiting variable evolutionary histories that were sometimes independent of the mitochondrial evolutionary history. Intraspecific HEG diversity was also high, with C. rangiferina especially bearing a range of HEGs with one unique to the species. This study reveals a rich history of events that have transformed mitochondrial genomes of Cladonia and related genera, allowing future study alongside a wealth of assembled genomes.

Genomic Survey of Flavin Monooxygenases in Wild and Cultivated Rice Provides Insight into Evolution and Functional Diversities

The flavin monooxygenase (FMO) enzyme was discovered in mammalian liver cells that convert a carcinogenic compound, N-N'-dimethylaniline, into a non-carcinogenic compound, N-oxide. Since then, many FMOs have been reported in animal systems for their primary role in the detoxification of xenobiotic compounds. In plants, this family has diverged to perform varied functions like pathogen defense, auxin biosynthesis, and S-oxygenation of compounds. Only a few members of this family, primarily those involved in auxin biosynthesis, have been functionally characterized in plant species. Thus, the present study aims to identify all the members of the FMO family in 10 different wild and cultivated Oryza species. Genome-wide analysis of the FMO family in different Oryza species reveals that each species has multiple FMO members in its genome and that this family is conserved throughout evolution. Taking clues from its role in pathogen defense and its possible function in ROS scavenging, we have also assessed the involvement of this family in abiotic stresses. A detailed in silico expression analysis of the FMO family in Oryza sativa subsp. japonica revealed that only a subset of genes responds to different abiotic stresses. This is supported by the experimental validation of a few selected genes using qRT-PCR in stress-sensitive Oryza sativa subsp. indica and stress-sensitive wild rice Oryza nivara. The identification and comprehensive in silico analysis of FMO genes from different Oryza species carried out in this study will serve as the foundation for further structural and functional studies of FMO genes in rice as well as other crop types.

Exome variants associated with asthma and allergy

The mutational spectrum of asthma and allergy associated genes is not known although recent biobank based exome sequencing studies included these traits. We therefore conducted a secondary analysis of exome data from 281,104 UK Biobank samples for association of mostly rare variants with asthma, allergic rhinitis and atopic dermatitis. Variants of interest (VOI) were tabulated, shared genes annotated and compared to earlier genome-wide SNP association studies (GWAS), whole genome sequencing, exome and bisulfit sequencing studies. 354 VOI were significantly associated with asthma, allergic rhinitis and atopic dermatitis. They cluster mainly in two large regions on chromosome 6 and 17. After exclusion of the variants associated with atopic dermatitis and redundant variants, 321 unique VOI remain in 122 unique genes. 30 genes are shared among the 87 genes with increased and the 65 genes with decreased risk for allergic disease. 85% of genes identified earlier by common GWAS SNPs are not replicated here. Most identified genes are located in interferon ɣ and IL33 signaling pathway. These genes include already known but also new pharmacological targets, including the IL33 receptor ST2/IL1RL1, as well as TLR1, ALOX15, GSDMA, BTNL2, IL13 and IKZF3. Future pharmacological studies will need to included these VOI for stratification of the study population paving the way to individualized treatment.

The Genome of the Mitochondrion-Related Organelle in Cepedea longa, a Large Endosymbiotic Opalinid Inhabiting the Recta of Frogs

Mitochondrion-related organelles (MROs) are loosely defined as degenerated mitochondria in anaerobic and microaerophilic lineages. Opalinids are commonly regarded as commensals in the guts of cold-blooded amphibians. It may represent an intermediate adaptation stage between the conventional aerobic mitochondria and derived anaerobic MROs. In the present study, we sequenced and analyzed the MRO genome of Cepedea longa. It has a linear MRO genome with large inverted repeat gene regions at both ends. Compared to Blastocystis and Proteromonas lacertae, the MRO genome of C. longa has a higher G + C content and repeat sequences near the central region. Although three Opalinata species have different morphological characteristics, phylogenetic analyses based on eight concatenated nad genes indicate that they are close relatives. The phylogenetic analysis showed that C. longa clustered with P. lacertae with strong support. The 18S rRNA gene-based phylogeny resolved the Opalinea clade as a sister clade to Karotomorpha, which then further grouped with Proteromonas. The paraphyly of Proteromonadea needs to be verified due to the lack of MRO genomes for key species, such as Karotomorpha, Opalina and Protoopalina. Besides, our dataset and analyses offered slight support for the paraphyly of Bigyra.

Evolutionary Comparison of the Complete Chloroplast Genomes in Convallaria Species and Phylogenetic Study of Asparagaceae

The genus Convallaria (Asparagaceae) comprises three herbaceous perennial species that are widely distributed in the understory of temperate deciduous forests in the Northern Hemisphere. Although Convallaria species have high medicinal and horticultural values, studies related to the phylogenetic analysis of this genus are few. In the present study, we assembled and reported five complete chloroplast (cp) sequences of three Convallaria species (two of C. keiskei Miq., two of C. majalis L., and one of C. montana Raf.) using Illumina paired-end sequencing data. The cp genomes were highly similar in overall size (161,365–162,972 bp), and all consisted of a pair of inverted repeats (IR) regions (29,140–29,486 bp) separated by a large single-copy (LSC) (85,183–85,521 bp) and a small single-copy (SSC) region (17,877–18,502 bp). Each cp genome contained the same 113 unique genes, including 78 protein-coding genes, 30 transfer RNA genes, and 4 ribosomal RNA genes. Gene content, gene order, AT content and IR/SC boundary structure were nearly identical among all of the Convallaria cp genomes. However, their lengths varied due to contraction/expansion at the IR/LSC borders. Simple sequence repeat (SSR) analyses indicated that the richest SSRs are A/T mononucleotides. Three highly variable regions (petA-psbJ, psbI-trnS and ccsA-ndhD) were identified as valuable molecular markers. Phylogenetic analysis of the family Asparagaceae using 48 cp genome sequences supported the monophyly of Convallaria, which formed a sister clade to the genus Rohdea. Our study provides a robust phylogeny of the Asparagaceae family. The complete cp genome sequences will contribute to further studies in the molecular identification, genetic diversity, and phylogeny of Convallaria.

Large-Scale Sequencing of Borreliaceae for the Construction of Pan-Genomic-Based Diagnostics

The acceleration of climate change has been associated with an alarming increase in the prevalence and geographic range of tick-borne diseases (TBD), many of which have severe and long-lasting effects-particularly when treatment is delayed principally due to inadequate diagnostics and lack of physician suspicion. Moreover, there is a paucity of treatment options for many TBDs that are complicated by diagnostic limitations for correctly identifying the offending pathogens. This review will focus on the biology, disease pathology, and detection methodologies used for the Borreliaceae family which includes the Lyme disease agent Borreliella burgdorferi. Previous work revealed that Borreliaceae genomes differ from most bacteria in that they are composed of large numbers of replicons, both linear and circular, with the main chromosome being the linear with telomeric-like termini. While these findings are novel, additional gene-specific analyses of each class of these multiple replicons are needed to better understand their respective roles in metabolism and pathogenesis of these enigmatic spirochetes. Historically, such studies were challenging due to a dearth of both analytic tools and a sufficient number of high-fidelity genomes among the various taxa within this family as a whole to provide for discriminative and functional genomic studies. Recent advances in long-read whole-genome sequencing, comparative genomics, and machine-learning have provided the tools to better understand the fundamental biology and phylogeny of these genomically-complex pathogens while also providing the data for the development of improved diagnostics and therapeutics.

Identification of Pseudo-R genes in Vitis vinifera and characterization of their role as immunomodulators in host-pathogen interactions

INTRODUCTION

Duplication events are fundamental to co-evolution in host-pathogen interactions. Pseudogenes (Ψs) are dysfunctional paralogs of functional genes and resistance genes (Rs) in plants are the key to disarming pathogenic invasions. Thus, deciphering the roles of pseudo-R genes in plant defense is momentous.

OBJECTIVES

This study aimed to functionally characterize diverse roles of the resistance Ψs as novel gene footprints and as significant gene regulators in the grapevine genome.

METHODS

PlantPseudo pipeline and HMM-profiling identified whole-genome duplication-derived (WGD) Ψs associated with resistance genes (Ψ-Rs). Further, novel antifungal and antimicrobial peptides were characterized for fungal associations using protein-protein docking with Erysiphe necator proteins. miRNA and tasiRNA target sites and transcription factor (TF) binding sites were predicted in Ψ-Rs. Finally, differential co-expression patterns in Ψ-Rs-lncRNAs-coding genes were identified using the UPGMA method.

RESULTS

2,746 Ψ-Rs were identified from 31,032 WGD Ψs in the genome of grapevine. 69-antimicrobial and 81-antifungal novel peptides were generated from Ψ-Rs. The putative genic potential was predicted for five novel antifungal peptides which were further characterized by docking against E. necator proteins. 395 out of 527 resistance loci-specific Ψ-Rs were acting as parental gene mimics. Further, to explore the diverse roles of Ψ-Rs in plant-defense, we identified 37,026 TF-binding sites, 208 miRNA, and 99 tasiRNA targeting sites on these Ψ-Rs. 194 Ψ-Rs were exhibiting tissue-specific expression patterns. The co-expression network analysis between Ψs-lncRNA-genes revealed six out of 79 pathogen-responsive Ψ-Rs as significant during pathogen invasion.

CONCLUSIONS

Our study provides pathogen responsive Ψ-Rs integral for pathogen invasion, which will offer a useful resource for future experimental validations. In addition, our findings on novel peptide generations from Ψ-Rs offer valuable insights which can serve as a useful resource for predicting novel genes with the futuristic potential of being investigated for their bioactivities in the plant system.

Noncoding RNAs in Thyroid-Follicular-Cell-Derived Carcinomas

Simple Summary

Thyroid tumors represent the most common neoplastic pathology of the endocrine system. Mutations occurring in oncogenes and tumor suppressor genes are responsible for thyroid carcinogenesis; however, the complete mutational landscape characterizing these neoplasias has not been completely unveiled. It has been established that only the 2% of the human genome codes for proteins, suggesting that the vast majority of the genome has regulatory capabilities, which, if altered, could account for the onset of cancer. Hence, many scientific efforts are currently focused on the characterization of the heterogeneous class of noncoding RNAs, which represent an abundant part of the transcribed noncoding genome. In this review, we mainly focus on the involvement of microRNAs, long noncoding RNAs, and pseudogenes in thyroid cancer. The determination of the diagnosis, prognosis, and treatment of thyroid cancers based on the evaluation of the noncoding RNA network could allow the implementation of a more personalized approach to fighting these pathologies.

Abstract

Among the thyroid neoplasias originating from follicular cells, we can include well-differentiated carcinomas, papillary (PTC) and follicular (FTC) thyroid carcinomas, and the undifferentiated anaplastic (ATC) carcinomas. Several mutations in oncogenes and tumor suppressor genes have already been observed in these malignancies; however, we are still far from the comprehension of their full regulation-altered landscape. Even if only 2% of the human genome has the ability to code for proteins, most of the noncoding genome is transcribed, constituting the heterogeneous class of noncoding RNAs (ncRNAs), whose alterations are associated with the development of several human diseases, including cancer. Hence, many scientific efforts are currently focused on the elucidation of their biological role. In this review, we analyze the scientific literature regarding the involvement of microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and pseudogenes in FTC, PTC, and ATC. Recent findings emphasized the role of lncRNAs in all steps of cancer progression. In particular, lncRNAs may control progression steps by regulating the expression of genes and miRNAs involved in cell proliferation, apoptosis, epithelial–mesenchymal transition, and metastatization. In conclusion, the determination of the diagnosis, prognosis, and treatment of cancer based on the evaluation of the ncRNA network could allow the implementation of a more personalized approach to fighting thyroid tumors.

Do pseudogenes pose a problem for metabarcoding marine animal communities?

Because DNA metabarcoding typically employs sequence diversity among mitochondrial amplicons to estimate species composition, nuclear mitochondrial pseudogenes (NUMTs) can inflate diversity. This study quantifies the incidence and attributes of NUMTs derived from the 658 bp barcode region of cytochrome c oxidase I (COI) in 156 marine animal genomes. NUMTs were examined to ascertain if they could be recognized by their possession of indels or stop codons. In total, 309 NUMTs ≥ 150 bp were detected, with an average of 1.98 per species (range = 0-33) and a mean length of 391 bp ± 200 bp. Among this total, 75 (24.3 %) lacked indels or stop codons. NUMTs appear to pose the greatest interpretational risk when short (< 313 bp) amplicons are used, such as in eDNA studies, dietary analyses, or processed fish identification. Employing the standard amplicon length (313 bp) for marine metabarcoding, NUMTs could potentially inflate the OTU count by 21% above the true species count while also raising intraspecific variation at COI by 15%. However, when both amplicon length and position are considered, inflation in OTU counts and in barcode variation were just 9% and 10%, respectively, suggesting NUMTs will not seriously distort biodiversity assessments. There was a weak positive correlation between genome size and NUMT count but no variation among phyla or trophic groups. Until bioinformatic advances improve NUMT detection, the best defense involves targeting long amplicons and developing reference databases that include both mitochondrial sequences and their NUMT derivatives.

CircSRSF4 Enhances Proliferation, Invasion, and Migration to Promote the Progression of Osteosarcoma via Rac1

(1) Background: At present, cancer cell metastasis is the main cause of death in patients with malignant tumors, and up to 23% of osteosarcoma patients have died due to lung and lymph node metastasis. Therefore, finding new molecules involved in tumor development can provide new strategies for the diagnosis and treatment of osteosarcoma patients. Circular RNAs (circRNAs) are a type of RNA molecule that are connected head-to-tail to form a closed ring. There is increasing evidence that circRNAs are RNA molecules with many biological functions in various diseases. However, the role and mechanism of circRNAs in osteosarcoma have rarely been reported. (2) Methods: The expression of circSRSF4 in osteosarcoma tissues and cell lines was detected by quantitative real-time PCR (RT-qPCR), and the result of high-throughput sequencing was verified. In order to explore the effect of circSRSF4 on tumor proliferation, invasion, and migration, a dual-luciferase reporter assay, RNA binding protein immunoprecipitation assay, cell counting kit-8 (CCK-8), transwell assay, scratch wound healing assay, Western blot analysis, and other experiments were carried out in vitro. Rescue experiments and a xenograft model confirmed that circSRSF4 directly acted on miR-224 to regulate Rac1 expression. (3) Results: The expression of circSRSF4 was significantly higher in osteosarcoma tissues and cell lines. Down-regulating the expression of circSRSF4 in vitro significantly inhibited the proliferation, invasion, and migration of cells, and also reduced the expression of Rac1, while the overexpression of Rac1 and miR-224 inhibition could reverse these effects. The inhibition of circSRSF4 expression in vivo also attenuated tumor growth. A mechanistic study showed that circSRSF4 can be used as an miR-224 sponge to up-regulate the expression of Rac1, thereby promoting the development of osteosarcoma. (4) Conclusions: CircSRSF4 acting as a ceRNA promotes the malignant behavior of osteosarcoma through the circSRSF4/miR-224/Rac1 axis, which provides a new theoretical basis for the clinical prevention and treatment of osteosarcoma and the study of related markers and intervention targets.

Interactions between strains govern the eco-evolutionary dynamics of microbial communities

Genomic data has revealed that genotypic variants of the same species, that is, strains, coexist and are abundant in natural microbial communities. However, it is not clear if strains are ecologically equivalent, and at what characteristic genetic distance they might exhibit distinct interactions and dynamics. Here, we address this problem by tracking 10 taxonomically diverse microbial communities from the pitcher plant Sarracenia purpurea in the laboratory for more than 300 generations. Using metagenomic sequencing, we reconstruct their dynamics over time and across scales, from distant phyla to closely related genotypes. We find that most strains are not ecologically equivalent and exhibit distinct dynamical patterns, often being significantly more correlated with strains from another species than their own. Although even a single mutation can affect laboratory strains, on average, natural strains typically decouple in their dynamics beyond a genetic distance of 100 base pairs. Using mathematical consumer-resource models, we show that these taxonomic patterns emerge naturally from ecological interactions between community members, but only if the interactions are coarse-grained at the level of strains, not species. Finally, by analyzing genomic differences between strains, we identify major functional hubs such as transporters, regulators, and carbohydrate-catabolizing enzymes, which might be the basis for strain-specific interactions. Our work suggests that fine-scale genetic differences in natural communities could be created and stabilized via the rapid diversification of ecological interactions between strains.

The characteristics of early-stage research into human genes are substantially different from subsequent research

Throughout the last 2 decades, several scholars observed that present day research into human genes rarely turns toward genes that had not already been extensively investigated in the past. Guided by hypotheses derived from studies of science and innovation, we present here a literature-wide data-driven meta-analysis to identify the specific scientific and organizational contexts that coincided with early-stage research into human genes throughout the past half century. We demonstrate that early-stage research into human genes differs in team size, citation impact, funding mechanisms, and publication outlet, but that generalized insights derived from studies of science and innovation only partially apply to early-stage research into human genes. Further, we demonstrate that, presently, genome biology accounts for most of the initial early-stage research, while subsequent early-stage research can engage other life sciences fields. We therefore anticipate that the specificity of our findings will enable scientists and policymakers to better promote early-stage research into human genes and increase overall innovation within the life sciences.

B Chromosomes’ Sequences in Yellow-Necked Mice Apodemus flavicollis—Exploring the Transcription

B chromosomes (Bs) are highly polymorphic additional chromosomes in the genomes of many species. Due to the dispensability of Bs and the lack of noticeable phenotypic effects in their carriers, they were considered genetically inert for a long time. Recent studies on Bs in Apodemus flavicollis revealed their genetic composition, potential origin, and spatial organization in the interphase nucleus. Surprisingly, the genetic content of Bs in this species is preserved in all studied samples, even in geographically distinct populations, indicating its biological importance. Using RT-PCR we studied the transcription activity of three genes (Rraga, Haus6, and Cenpe) previously identified on Bs in A. flavicollis. We analysed mRNA isolated from spleen tissues of 34 animals harboring different numbers of Bs (0–3).The products of transcriptional activity of the analysed sequences differ in individuals with and without Bs. We recorded B-genes and/or genes from the standard genome in the presence of Bs, showing sex-dependent higher levels of transcriptional activity. Furthermore, the transcriptional activity of Cenpe varied with the age of the animals differently in the group with and without Bs. With aging, the amount of product was only found to significantly decrease in B carriers. The potential biological significance of all these differences is discussed in the paper.

Widespread retention of ohnologs in key developmental gene families following whole-genome duplication in arachnopulmonates

Whole-genome duplications (WGDs) have occurred multiple times during animal evolution, including in lineages leading to vertebrates, teleosts, horseshoe crabs, and arachnopulmonates. These dramatic events initially produce a wealth of new genetic material, generally followed by extensive gene loss. It appears, however, that developmental genes such as homeobox genes, signaling pathway components and microRNAs are frequently retained as duplicates (so-called ohnologs) following WGD. These not only provide the best evidence for WGD, but an opportunity to study its evolutionary consequences. Although these genes are well studied in the context of vertebrate WGD, similar comparisons across the extant arachnopulmonate orders are patchy. We sequenced embryonic transcriptomes from two spider species and two amblypygid species and surveyed three important gene families, Hox, Wnt, and frizzled, across these and 12 existing transcriptomic and genomic resources for chelicerates. We report extensive retention of putative ohnologs, further supporting the ancestral arachnopulmonate WGD. We also found evidence of consistent evolutionary trajectories in Hox and Wnt gene repertoires across three of the six arachnopulmonate orders, with interorder variation in the retention of specific paralogs. We identified variation between major clades in spiders and are better able to reconstruct the chronology of gene duplications and losses in spiders, amblypygids, and scorpions. These insights shed light on the evolution of the developmental toolkit in arachnopulmonates, highlight the importance of the comparative approach within lineages, and provide substantial new transcriptomic data for future study.

An Enhanced Random Forests Approach to Predict Heart Failure From Small Imbalanced Gene Expression Data

Myocardial infarctions and heart failure are the cause of more than 17 million deaths annually worldwide. ST-segment elevation myocardial infarctions (STEMI) require timely treatment, because delays of minutes have serious clinical impacts. Machine learning can provide alternative ways to predict heart failure and identify genes involved in heart failure. For these scopes, we applied a Random Forests classifier enhanced with feature elimination to microarray gene expression of 111 patients diagnosed with STEMI, and measured the classification performance through standard metrics such as the Matthews correlation coefficient (MCC) and area under the receiver operating characteristic curve (ROC AUC). Afterwards, we used the same approach to rank all genes by importance, and to detect the genes more strongly associated with heart failure. We validated this ranking by literature review and gene set enrichment analysis. Our classifier employed to predict heart failure achieved MCC = +0.87 and ROC AUC = 0.918, and our analysis identified KLHL22, WDR11, OR4Q3, GPATCH3, and FAH as top five protein-coding genes related to heart failure. Our results confirm the effectiveness of machine learning feature elimination in predicting heart failure from gene expression, and the top genes found by our approach will be able to help biologists and cardiologists further our understanding of heart failure.

Eukaryotic Genomes Show Strong Evolutionary Conservation of k-mer Composition and Correlation Contributions between Introns and Intergenic Regions

Several strongly conserved DNA sequence patterns in and between introns and intergenic regions (IIRs) consisting of short tandem repeats (STRs) with repeat lengths <3 bp have already been described in the kingdom of Animalia. In this work, we expanded the search and analysis of conserved DNA sequence patterns to a wider range of eukaryotic genomes. Our aims were to confirm the conservation of these patterns, to support the hypothesis on their functional constraints and/or the identification of unknown patterns. We pairwise compared genomic DNA sequences of genes, exons, CDS, introns and intergenic regions of 34 Embryophyta (land plants), 30 Protista and 29 Fungi using established k-mer-based (alignment-free) comparison methods. Additionally, the results were compared with values derived for Animalia in former studies. We confirmed strong correlations between the sequence structures of IIRs spanning over the entire domain of Eukaryotes. We found that the high correlations within introns, intergenic regions and between the two are a result of conserved abundancies of STRs with repeat units ≤2 bp (e.g., (AT)n). For some sequence patterns and their inverse complementary sequences, we found a violation of equal distribution on complementary DNA strands in a subset of genomes. Looking at mismatches within the identified STR patterns, we found specific preferences for certain nucleotides stable over all four phylogenetic kingdoms. We conclude that all of these conserved patterns between IIRs indicate a shared function of these sequence structures related to STRs.

Systematic functional interrogation of human pseudogenes using CRISPRi

BACKGROUND

The human genome encodes over 14,000 pseudogenes that are evolutionary relics of protein-coding genes and commonly considered as nonfunctional. Emerging evidence suggests that some pseudogenes may exert important functions. However, to what extent human pseudogenes are functionally relevant remains unclear. There has been no large-scale characterization of pseudogene function because of technical challenges, including high sequence similarity between pseudogene and parent genes, and poor annotation of transcription start sites.

RESULTS

To overcome these technical obstacles, we develop an integrated computational pipeline to design the first genome-wide library of CRISPR interference (CRISPRi) single-guide RNAs (sgRNAs) that target human pseudogene promoter-proximal regions. We perform the first pseudogene-focused CRISPRi screen in luminal A breast cancer cells and reveal approximately 70 pseudogenes that affect breast cancer cell fitness. Among the top hits, we identify a cancer-testis unitary pseudogene, MGAT4EP, that is predominantly localized in the nucleus and interacts with FOXA1, a key regulator in luminal A breast cancer. By enhancing the promoter binding of FOXA1, MGAT4EP upregulates the expression of oncogenic transcription factor FOXM1. Integrative analyses of multi-omic data from the Cancer Genome Atlas (TCGA) reveal many unitary pseudogenes whose expressions are significantly dysregulated and/or associated with overall/relapse-free survival of patients in diverse cancer types.

CONCLUSIONS

Our study represents the first large-scale study characterizing pseudogene function. Our findings suggest the importance of nuclear function of unitary pseudogenes and underscore their underappreciated roles in human diseases. The functional genomic resources developed here will greatly facilitate the study of human pseudogene function.

Pseudogene Transcripts in Head and Neck Cancer: Literature Review and In Silico Analysis

Once considered nonfunctional, pseudogene transcripts are now known to provide valuable information for cancer susceptibility, including head and neck cancer (HNC), a serious health problem worldwide, with about 50% unimproved overall survival over the last decades. The present review focuses on the role of pseudogene transcripts involved in HNC risk and prognosis. We combined current literature and in silico analyses from The Cancer Genome Atlas (TCGA) database to identify the most deregulated pseudogene transcripts in HNC and their genetic variations. We then built a co-expression network and performed gene ontology enrichment analysis to better understand the pseudogenes’ interactions and pathways in HNC. In the literature, few pseudogenes have been studied in HNC. Our in silico analysis identified 370 pseudogene transcripts associated with HNC, where SPATA31D5P, HERC2P3, SPATA31C2, MAGEB6P1, SLC25A51P1, BAGE2, DNM1P47, SPATA31C1, ZNF733P and OR2W5 were found to be the most deregulated and presented several genetic alterations. NBPF25P, HSP90AB2P, ZNF658B and DPY19L2P3 pseudogenes were predicted to interact with 12 genes known to participate in HNC, DNM1P47 was predicted to interact with the TP53 gene, and HLA-H pseudogene was predicted to interact with HLA-A and HLA-B genes. The identified pseudogenes were associated with cancer biology pathways involving cell communication, response to stress, cell death, regulation of the immune system, regulation of gene expression, and Wnt signaling. Finally, we assessed the prognostic values of the pseudogenes with the Kaplan–Meier Plotter database, and found that expression of SPATA31D5P, SPATA31C2, BAGE2, SPATA31C1, ZNF733P and OR2W5 pseudogenes were associated with patients’ survival. Due to pseudogene transcripts’ potential for cancer diagnosis, progression, and as therapeutic targets, our study can guide new research to HNC understanding and development of new target therapies.

Comparisons within the Rice GA 2-Oxidase Gene Family Revealed Three Dominant Paralogs and a Functional Attenuated Gene that Led to the Identification of Four Amino Acid Variants Associated with GA Deactivation Capability

BACKGROUND

GA 2-oxidases (GA2oxs) are involved in regulating GA homeostasis in plants by inactivating bioactive GAs through 2β-hydroxylation. Rice GA2oxs are encoded by a family of 10 genes; some of them have been characterized, but no comprehensive comparisons for all these genes have been conducted.

RESULTS

Rice plants with nine functional GA2oxs were demonstrated in the present study, and these genes not only were differentially expressed but also revealed various capabilities for GA deactivation based on their height-reducing effects in transgenic plants. Compared to that of wild-type plants, the relative plant height (RPH) of transgenic plants was scored to estimate their reducing effects, and 8.3% to 59.5% RPH was observed. Phylogenetic analysis of class I GA2ox genes revealed two functionally distinct clades in the Poaceae. The OsGA2ox3, 4, and 8 genes belonging to clade A showed the most severe effect (8.3% to 8.7% RPH) on plant height reduction, whereas the OsGA2ox7 gene belonging to clade B showed the least severe effect (59.5% RPH). The clade A OsGA2ox3 gene contained two conserved C186/C194 amino acids that were crucial for enzymatic activity. In the present study, these amino acids were replaced with OsGA2ox7-conserved arginine (C186R) and proline (C194P), respectively, or simultaneously (C186R/C194P) to demonstrate their importance in planta. Another two amino acids, Q220 and Y274, conserved in OsGA2ox3 were substituted with glutamic acid (E) and phenylalanine (F), respectively, or simultaneously to show their significance in planta. In addition, through sequence divergence, RNA expression profile and GA deactivation capability analyses, we proposed that OsGA2ox1, OsGA2ox3 and OsGA2ox6 function as the predominant paralogs in each of their respective classes.

CONCLUSIONS

This study demonstrates rice has nine functional GA2oxs and the class I GA2ox genes are divided into two functionally distinct clades. Among them, the OsGA2ox7 of clade B is a functional attenuated gene and the OsGA2ox1, OsGA2ox3 and OsGA2ox6 are the three predominant paralogs in the family.

LncRNA NEAT1 regulated diabetic retinal epithelial-mesenchymal transition through regulating miR-204/SOX4 axis

AIM

Epithelial-mesenchymal transition (EMT) of retinal pigment epithelium (RPE) cells is the key of the development of diabetic retinopathy (DR), and lncRNA NEAT1 could accelerate EMT in diabetic nephropathy. Meanwhile, as a diabetes susceptibility gene, whether sex-determining region Y-related (SRY) high-mobility group box 4 (SOX4) has relationship with lncRNA NEAT1 in DR remains unclear.

METHODS

Firstly, NEAT1, SOX4 and miR-204 were evaluated by qRT-PCR (quantitative reverse-transcriptase PCR) under high glucose condition. Then, cell viability, proliferation, migration and invasion were respectively detected by MTT, BrdU staining, wound healing and transwell assay after NEAT1 knockdown or miR-204 overexpression. Also, the EMT-related proteins were examined by western blot and cell immunofluorescence assay. In order to confirm the relationship between miR-204 and NEAT1 or SOX4, dual luciferase reporter gene assay was conducted. At the same time, the protein levels of SOX4 and EMT-related proteins were investigated by immunohistochemistry in vivo.

RESULTS

High glucose upregulated NEAT1 and SOX4 and downregulated miR-204 in ARPE19 cells. NEAT1 knockdown or miR-204 overexpression inhibited the proliferation and EMT progression of ARPE19 cells induced by high glucose. NEAT1 was identified as a molecular sponge of miR-204 to increase the level of SOX4. The effect of NEAT1 knockdown on the progression of EMT under high glucose condition in ARPE19 cells could be reversed by miR-204 inhibitor. Also, NEAT1 knockdown inhibited retinal EMT in diabetic mice.

CONCLUSION

NEAT1 regulated the development of EMT in DR through miR-204/SOX4 pathway, which could provide reference for clinical prevention and treatment.

Lack of CpG islands in human unitary pseudogenes and its implication

CpG islands (CGIs) are aggregation of CpG dinucleotides in the promoters of mammalian genes. These CGIs are present in almost all the housekeeping genes and some tissue-specific genes in the mammalian genome. Extensive research has been done on the prevalence and role of CGIs in protein-coding genes. However, little is known about CGIs in pseudogenes. In the current research project, we focused on CGIs in three main classes of pseudogenes e.g., duplicated pseudogenes (DPGs), processed pseudogenes (PPGs), and unitary pseudogenes (UPGs). We discovered a predominant absence of CGIs in the promoters of all three pseudogenes. We also compared the CGI profile of these pseudogenes with their parent genes and found that unitary pseudogenes (UPGs) differ from the DPGs and PPGs in the sense that in the latter, lack of CGIs is a consequential event while in UPGs, this lack of CGIs in their promoters is not a result of pseudogenization process. We also discussed the implication of the results obtained from this comparison. To our knowledge, this is the first-ever study highlighting this aspect of UPGs throwing new insights into the evolution of genome in general and especially in the context of pseudogenes.

Roles of ncRNAs as ceRNAs in Gastric Cancer

Although ignored in the past, with the recent deepening of research, significant progress has been made in the field of non-coding RNAs (ncRNAs). Accumulating evidence has revealed that microRNA (miRNA) response elements regulate RNA. Long ncRNAs, circular RNAs, pseudogenes, miRNAs, and messenger RNAs (mRNAs) form a competitive endogenous RNA (ceRNA) network that plays an essential role in cancer and cardiovascular, neurodegenerative, and autoimmune diseases. Gastric cancer (GC) is one of the most common cancers, with a high degree of malignancy. Considerable progress has been made in understanding the molecular mechanism and treatment of GC, but GC’s mortality rate is still high. Studies have shown a complex ceRNA crosstalk mechanism in GC. lncRNAs, circRNAs, and pseudogenes can interact with miRNAs to affect mRNA transcription. The study of the involvement of ceRNA in GC could improve our understanding of GC and lead to the identification of potential effective therapeutic targets. The research strategy for ceRNA is mainly to screen the different miRNAs, lncRNAs, circRNAs, pseudogenes, and mRNAs in each sample through microarray or sequencing technology, predict the ceRNA regulatory network, and, finally, conduct functional research on ceRNA. In this review, we briefly discuss the proposal and development of the ceRNA hypothesis and the biological function and principle of ceRNAs in GC, and briefly introduce the role of ncRNAs in the GC’s ceRNA network.

Long non‑coding RNA HOTTIP enhances the fibrosis of lung tissues by regulating the miR‑744‑5p/PTBP1 signaling axis

Fibrosis of lung tissue can induce the occurrence and development of numerous types of lung disease. The expression levels of the long non-coding RNA (lncRNA) HOXA distal transcript antisense RNA (HOTTIP) have been reported to be upregulated during the development of fibrosis in liver tissues, which subsequently activated hepatic stellate cells. However, whether the lncRNA HOTTIP participates in the occurrence and development of lung fibrosis remains unknown. The present study aimed to investigate the role of lncRNA HOTTIP in lung fibrosis and its potential mechanism. In the present study, A549 cells were stimulated with TGF-β1 to induce lung fibrosis in vitro. A549 was transfected with short hairpin RNA-HOTTP, overexpression-polypyrimidine tract binding protein 1 (PTBP1), microRNA (miR)-744-5p mimic or miR-744-5p to regulate gene expression. Cell proliferation and migration were determined using 5′-ethynl-2′-deoxyuridine and wound healing assays, respectively. The expression levels of α-smooth muscle actin, collagen I, collagen III and fibronectin 1 were analyzed using western blotting. starBase was used to identify molecules that may interact with the lncRNA HOTTIP and dual luciferase reporter assays were used to validate the findings. Moreover, an in vivo lung fibrosis model was established by bleomycin induction in mice. Histological injury was observed using hematoxylin and eosin and masson staining. The results of the present study revealed that the proliferation and migration of A549 cells were both suppressed following the knockdown of HOTTIP. The lncRNA HOTTIP was found to target and downregulate the expression levels of miR-744-5p. The overexpression of miR-744-5p inhibited the proliferation and migration of A549 cells. Furthermore, miR-744-5p targeted and downregulated the expression levels of PTBP1. It was subsequently demonstrated that the overexpression of PTBP1 rescued miR-744-5p-induced suppression of the proliferation and migration of A549 cells. The knockdown of lncRNA HOTTIP expression also relieved the fibrosis of the lung tissues of mice. In conclusion, the results of the present study suggested that the lncRNA HOTTIP may promote the fibrosis of lung tissues by downregulating the expression levels of miR-744-5p and upregulating the expression levels of PTBP1.

Programmed Deviations of Ribosomes From Standard Decoding in Archaea

Genetic code decoding, initially considered to be universal and immutable, is now known to be flexible. In fact, in specific genes, ribosomes deviate from the standard translational rules in a programmed way, a phenomenon globally termed recoding. Translational recoding, which has been found in all domains of life, includes a group of events occurring during gene translation, namely stop codon readthrough, programmed ± 1 frameshifting, and ribosome bypassing. These events regulate protein expression at translational level and their mechanisms are well known and characterized in viruses, bacteria and eukaryotes. In this review we summarize the current state-of-the-art of recoding in the third domain of life. In Archaea, it was demonstrated and extensively studied that translational recoding regulates the decoding of the 21st and the 22nd amino acids selenocysteine and pyrrolysine, respectively, and only one case of programmed -1 frameshifting has been reported so far in Saccharolobus solfataricus P2. However, further putative events of translational recoding have been hypothesized in other archaeal species, but not extensively studied and confirmed yet. Although this phenomenon could have some implication for the physiology and adaptation of life in extreme environments, this field is still underexplored and genes whose expression could be regulated by recoding are still poorly characterized. The study of these recoding episodes in Archaea is urgently needed.

Genome-Wide Analysis of Coding and Non-coding RNA Reveals a Conserved miR164-NAC-mRNA Regulatory Pathway for Disease Defense in Populus

MicroRNAs (miRNAs) contribute to plant defense responses by increasing the overall genetic diversity; however, their origins and functional importance in plant defense remain unclear. Here, we employed Illumina sequencing technology to assess how miRNA and messenger RNA (mRNA) populations vary in the Chinese white poplar (Populus tomentosa) during a leaf black spot fungus (Marssonina brunnea) infection. We sampled RNAs from infective leaves at conidia germinated stage [12 h post-inoculation (hpi)], infective vesicles stage (24 hpi), and intercellular infective hyphae stage (48 hpi), three essential stages associated with plant colonization and biotrophic growth in M. brunnea fungi. In total, 8,938 conserved miRNA-target gene pairs and 3,901 Populus-specific miRNA-target gene pairs were detected. The result showed that Populus-specific miRNAs (66%) were more involved in the regulation of the disease resistance genes. By contrast, conserved miRNAs (>80%) target more whole-genome duplication (WGD)-derived transcription factors (TFs). Among the 1,023 WGD-derived TF pairs, 44.9% TF pairs had only one paralog being targeted by a miRNA that could be due to either gain or loss of a miRNA binding site after the WGD. A conserved hierarchical regulatory network combining promoter analyses and hierarchical clustering approach uncovered a miR164–NAM, ATAF, and CUC (NAC) transcription factor–mRNA regulatory module that has potential in Marssonina defense responses. Furthermore, analyses of the locations of miRNA precursor sequences reveal that pseudogenes and transposon contributed a certain proportion (∼30%) of the miRNA origin. Together, these observations provide evolutionary insights into the origin and potential roles of miRNAs in plant defense and functional innovation.

Pseudogene ANXA2P2 knockdown shows tumor-suppressive function by inhibition of the PI3K/PKB pathway in glioblastoma cells

The pseudogene annexin A2 pseudogene 2 (ANXA2P2) is highly expressed in glioblastoma (GBM). However, its role and mechanism involved in the progression of GBM remain poorly understood. ANXA2P2 messenger RNA expression was measured by quantitative reverse transcription-polymerase chain reaction. The protein levels were detected by Western blot. Cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase (LDH) release assays. Cell invasive ability was investigated by the transwell assay and by epithelial-mesenchymal transition (EMT). Cell apoptosis was examined by flow cytometry. The results showed that ANXA2P2 expression was increased in GBM tissues and cells. Silencing of ANXA2P2 inhibited the activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (PKB) pathway in GBM cells. Knockdown of ANXA2P2 decreased cell viability, promoted LDH release, suppressed cell invasive ability, and EMT, and induced cell apoptosis in GBM cells. The addition of the PI3K/PKB activator 740Y-P abrogated the effects of ANXA2P2 knockdown on cell viability, LDH release, invasive ability, and apoptosis. In conclusion, knockdown of ANXA2P2 inhibited cell viability and invasion but promoted the apoptotic rate by suppressing the PI3K/PKB pathway in GBM cells. ANXA2P2 may represent a new target for the treatment of GBM.

Some Examples of the Use of Molecular Markers for Needs of Basic Biology and Modern Society

Application of molecular genetic markers appeared to be very fruitful in achieving many goals, including (i) proving the theoretic basements of general biology and (ii) assessment of worldwide biodiversity. Both are provided in the present meta-analysis and a review as the main signal. One of the basic current challenges in modern biology in the face of new demands in the 21st century is the validation of its paradigms such as the synthetic theory of evolution (STE) and biological species concept (BSC). Another of most valuable goals is the biodiversity assessment for a variety of social needs including free web-based information resources about any living being, renovation of museum collections, nature conservation that recognized as a global project, iBOL, as well as resolving global trading problems such as false labeling of species specimens used as food, drug components, entertainment, etc. The main issues of the review are focused on animals and combine four items. (1) A combination of nDNA and mtDNA markers best suits the identification of hybrids and estimation of genetic introgression. (2) The available facts on nDNA and mtDNA diversity seemingly make introgression among many taxa obvious, although it is evident, that introgression may be quite restricted or asymmetric, thus, leaving at least the "source" taxon (taxa) intact. (3) If we consider sexually reproducing species in marine and terrestrial realms introgressed, as it is still evident in many cases, then we should recognize that the BSC, in view of the complete lack of gene flow among species, is inadequate because many zoological species are not biological ones yet. However, vast modern molecular data have proven that sooner or later they definitely become biological species. (4) An investigation into the fish taxa divergence using the BOLD database shows that most gene trees are basically monophyletic and interspecies reticulations are quite rare.

Gauging the trends of pseudogenes in plants

Pseudogenes, the debilitated parts of ancient genes, were previously scrapped off as junk or discarded genes with no functional significance. Pseudogenes have come under scrutiny for their functionality, since recent studies have unveiled their importance in the regulation of their corresponding parent genes and various biological mechanisms. Despite the enormous occurrence of pseudogenes in plants, the lack of experimental validation has contributed toward their unresolved roles in gene regulation. Contrarily, most of the studies associated with gene regulation have been mainly reported for humans, mice, and other mammalian genomes. Consequently, in order to present a cumulative report on plant-based pseudogenes research, an attempt has been made to assemble multiple studies presenting the pseudogene classification, the prediction and the determination of comparative accuracies of various computational pipelines, and recent trends in analyzing their biological functions, and regulatory mechanisms. This review represents the classical, as well as the recent advances on pseudogene identification and their potential roles in transcriptional regulation, which could possibly invigorate the quality of genome annotation, evolutionary analysis, and complexity surrounding the regulatory pathways in plants. Thus, when the ambiguous boundary girdling the pseudogenes eventually recedes on account of their explicit orchestration role, research in flora would no longer saunter compared to that on fauna.

Complete chloroplast genomes of Chinese wild-growing Vitis species: molecular structures and comparative and adaptive radiation analysis

As a basalmost family of Vitaceae, Chinese wild Vitis species offer key insights into the demographic history of grapes. In this study, we obtained 10 complete chloroplast (cp) genomes from Chinese wild-growing Vitis species based on our whole genome re-sequencing data. These chloroplast genomes ranged from 160,838 to 232,020 bp in size and exhibited typical quadripartite structures. Comparative analyses revealed that inverted repeat (IR) regions are especially abundant and contribute to cp genome arrangements. Phylogenetic analysis of the whole Vitis cp genomes supported three clearly partitioned main origins, in keeping with their geographic distributions, among which East Asian species from China were found to be sister species with Eurasian Vitis species but exhibited significant divergence from the North American group. Two well-supported subgroups were observed within the Chinese wild-growing Vitis species. Among these species, Vitis piasezkii and Vitis betulifolia were closely related species, exhibiting a support rate of 100%. The molecular clock-based divergence time suggested that the earliest split subspecies was Vitis pseudoreticulata, which further indicated that the origin and initial gene pool are located in southern China (the habitat of V. pseudoreticulata is located in the region). Coincidentally, the divergence time was during the Pleistocene period (2.6-0.1 Ma). Due to glacial/interglacial temperature fluctuations, cold-adapted subspecies, e.g., Vitis amurensis, could re-colonize new habitats. Our results may help to elucidate the adaptive radiation of Chinese wild Vitis species in different environments.

Non-Coding RNAs in Cancer Diagnosis and Therapy: Focus on Lung Cancer

Over the last several decades, clinical evaluation and treatment of lung cancers have largely improved with the classification of genetic drivers of the disease, such as EGFR, ALK, and ROS1. There are numerous regulatory factors that exert cellular control over key oncogenic pathways involved in lung cancers. In particular, non-coding RNAs (ncRNAs) have a diversity of regulatory roles in lung cancers such that they have been shown to be involved in inducing proliferation, suppressing apoptotic pathways, increasing metastatic potential of cancer cells, and acquiring drug resistance. The dysregulation of various ncRNAs in human cancers has prompted preclinical studies examining the therapeutic potential of restoring and/or inhibiting these ncRNAs. Furthermore, ncRNAs demonstrate tissue-specific expression in addition to high stability within biological fluids. This makes them excellent candidates as cancer biomarkers. This review aims to discuss the relevance of ncRNAs in cancer pathology, diagnosis, and therapy, with a focus on lung cancer.

Structural characterization and duplication modes of pseudogenes in plants

We identified and characterized the pseudogene complements of five plant species: four dicots (Arabidopsis thaliana, Vitis vinifera, Populus trichocarpa and Phaseolus vulgaris) and one monocot (Oryza sativa). Retroposition was considered of modest importance for pseudogene formation in all investigated species except V. vinifera, which showed an unusually high number of retro-pseudogenes in non coding genic regions. By using a pipeline for the classification of sequence duplicates in plant genomes, we compared the relative importance of whole genome, tandem, proximal, transposed and dispersed duplication modes in the pseudo and functional gene complements. Pseudogenes showed higher tendencies than functional genes to genomic dispersion. Dispersed pseudogenes were prevalently fragmented and showed high sequence divergence at flanking regions. On the contrary, those deriving from whole genome duplication were proportionally less than expected based on observations on functional loci and showed higher levels of flanking sequence conservation than dispersed pseudogenes. Pseudogenes deriving from tandem and proximal duplications were in excess compared to functional loci, probably reflecting the high evolutionary rate associated with these duplication modes in plant genomes. These data are compatible with high rates of sequence turnover at neutral sites and double strand break repairs mediated duplication mechanisms.

Evolution and Expression of the Immune System of a Facultatively Anadromous Salmonid

Vertebrates have evolved a complex immune system required for the identification of and coordinated response to harmful pathogens. Migratory species spend periods of their life-cycle in more than one environment, and their immune system consequently faces a greater diversity of pathogens residing in different environments. In facultatively anadromous salmonids, individuals may spend parts of their life-cycle in freshwater and marine environments. For species such as the brown trout Salmo trutta, sexes differ in their life-histories with females more likely to migrate to sea while males are more likely to stay and complete their life-cycle in their natal river. Salmonids have also undergone a lineage-specific whole genome duplication event, which may provide novel immune innovations but our current understanding of the differences in salmonid immune expression between the sexes is limited. We characterized the brown trout immune gene repertoire, identifying a number of canonical immune genes in non-salmonid teleosts to be duplicated in S. trutta, with genes involved in innate and adaptive immunity. Through genome-wide transcriptional profiling (“RNA-seq”) of male and female livers to investigate sex differences in gene expression amplitude and alternative splicing, we identified immune genes as being generally male-biased in expression. Our study provides important insights into the evolutionary consequences of whole genome duplication events on the salmonid immune gene repertoire and how the sexes differ in constitutive immune expression.

Analysis of Stop Codons within Prokaryotic Protein-Coding Genes Suggests Frequent Readthrough Events

Nonsense mutations turn a coding (sense) codon into an in-frame stop codon that is assumed to result in a truncated protein product. Thus, nonsense substitutions are the hallmark of pseudogenes and are used to identify them. Here we show that in-frame stop codons within bacterial protein-coding genes are widespread. Their evolutionary conservation suggests that many of them are not pseudogenes, since they maintain dN/dS values (ratios of substitution rates at non-synonymous and synonymous sites) significantly lower than 1 (this is a signature of purifying selection in protein-coding regions). We also found that double substitutions in codons—where an intermediate step is a nonsense substitution—show a higher rate of evolution compared to null models, indicating that a stop codon was introduced and then changed back to sense via positive selection. This further supports the notion that nonsense substitutions in bacteria are relatively common and do not necessarily cause pseudogenization. In-frame stop codons may be an important mechanism of regulation: Such codons are likely to cause a substantial decrease of protein expression levels.

Pseudogenes in Cardiovascular Disease

Cardiovascular disease is the main disease that affects human life span. In recent years, the disease has been increasingly addressed at the molecular levels, for example, pseudogenes are now known to be involved in the pathogenesis and development of cardiovascular diseases. Pseudogenes are non-coding homologs of protein-coding genes and were once called “junk gene.” Since they are highly homologous to their functional parental genes, it is somewhat difficult to distinguish them. With the development of sequencing technology and bioinformatics, pseudogenes have become readily identifiable. Recent studies indicate that pseudogenes are closely related to cardiovascular diseases. This review provides an overview of pseudogenes and their roles in the pathogenesis of cardiovascular diseases. This new knowledge adds to our understanding of cardiovascular disease at the molecular level and will help develop new biomarkers and therapeutic approaches designed to prevent and treat the disease.