Portion Of Genome Research Articles

Genome location, evolution and centromeric contribution of satellite DNAs shared between the two closely related species Drosophila serido and D. antonietae (repleta group, buzzatii cluster).

Satellite DNAs are highly repetitive, tandemly arranged sequences, typically making up large portions (> 20%) of the eukaryotic genome. Most satDNAs are fast evolving and changes in their abundance and nucleotide composition may be related to genetic incompatibilities between species. Here, we used Illumina paired-end sequencing raw data and graph-based read-clustering with the TAREAN bioinformatic tool to study the satDNAs in two cactophilic neotropical cryptic species of Drosophila from the buzzatii cluster (repleta group), D. serido and D. antonietae, from five localities in Brazil. Both species share the same four families of satDNAs: pBuM, DBC-150, CDSTR138 and CDSTR230. They represent less than 4% of the genomic DNA and there are no large differences in the abundance of each satDNA between species. Despite not being the most abundant satDNA, CDSTR138 was found to be associated with most centromeres. All four satDNAs showed instances where repeats are more homogeneous within than between species, a phenomenon known as concerted evolution. On the other hand, there was no evidence for concerted evolution at the population level. Thus, these satDNAs may also be useful as potential markers for species identification. The low levels of satDNA differentiation (both quantitatively as qualitatively) between the two species might be among the reasons that allowed the establishment of a hybrid zone between the two species in the southern coast of Brazil.

Noncoding RNA, friend or foe for nephrolithiasis?

Nephrolithiasis is one of the most common diseases in urology, characterized by notable incidence and recurrence rates, leading to significant morbidity and financial burden. Despite its prevalence, the precise mechanisms underlying stone formation remain incompletely understood, thus hindering significant advancements in kidney stone management over the past three decades. Investigating the pivotal biological molecules that govern stone formation has consistently been a challenging and high-priority task. A significant portion of mammalian genomes are transcribed into noncoding RNAs (ncRNAs), which have the ability to modulate gene expression and disease progression. They are thus emerging as a novel target class for diagnostics and pharmaceutical exploration. In recent years, the role of ncRNAs in stone formation has attracted burgeoning attention. They have been found to influence stone formation by regulating ion transportation, oxidative stress injury, inflammation, osteoblastic transformation, autophagy, and pyroptosis. These findings contributes new perspectives on the pathogenesis of nephrolithiasis. To enhance our understanding of the diagnostic and therapeutic potential of nephrolithiasis-associated ncRNAs, we summarized the expression profiles, biological functions, and clinical significance of these ncRNAs in the current review.

Multisample motif discovery and visualization for tandem repeats.

Tandem Repeats (TR) occupy a significant portion of the human genome and are the source of polymorphism due to variations in sizes and motif compositions. Some of these variations have been associated with various neuropathological disorders, highlighting the clinical importance of assessing the motif structure of TRs. Moreover, assessing the TR motif variation can offer valuable insights into evolutionary dynamics and population structure. Previously, characterizations of TRs have been limited by short-read sequencing technology, which lacks the ability to accurately capture the full TR sequences. As long-read sequencing becomes more accessible and can capture the full complexity of TRs, there is now also a need for tools to characterize and analyze TRs using long-read data across multiple samples. In this study, we present MotifScope, a novel algorithm for characterization and visualization of TRs based on a de novo k-mer approach for motif discovery. Comparative analysis against established tools reveals that MotifScope can identify a greater number of motifs and more accurately represent the underlying repeat sequence. Moreover, MotifScope has been specifically designed to enable motif composition comparisons across assemblies of different individuals, as well as across long-read sequencing reads within an individual, through combined motif discovery and sequence alignment. We showcase potential applications of MotifScope in diverse fields, including population genetics, clinical settings, and forensic analyses.

A B cell screen against endogenous retroviruses identifies glycan-reactive IgM that recognizes a broad array of enveloped viruses.

Endogenous retroviruses (ERVs), comprising a substantial portion of the vertebrate genome, are remnants of ancient genetic invaders. ERVs with near-intact coding potential reactivate in B cell-deficient mice. To study how B cells contribute to host anti-ERV immunity, we used an antigen-baiting strategy to enrich B cells reactive to ERV surface antigens. We identified ERV-reactive B-1 cells expressing germline-encoded natural IgM antibodies in naïve mice, the level of which further increases upon innate immune sensor stimulation. B cell receptor repertoire profiling of ERV-reactive B-1 cells revealed increased usage of the Igh VH gene that gives rise to glycan-specific antibodies targeting terminal N-acetylglucosamine moieties on ERV glycoproteins, which further engage the complement pathway to mediate anti-ERV responses. These same antibodies also recognize glycoproteins of other enveloped viruses but not self-proteins. These results reveal an innate antiviral mechanism of germline-encoded antibodies with broad reactivity to enveloped viruses, which constitutes a natural antibody repertoire capable of preventing the emergence of infectious ERVs.

Polymorphic pseudogenes in the human genome - a comprehensive assessment

Background: Over the past decade, variations of the coding portion of the human genome have become increasingly evident. In this study, we focus on polymorphic pseudogenes, a unique and relatively unexplored type of pseudogene whose inactivating mutations have not yet been fixed in the human genome at the global population level. Thus, polymorphic pseudogenes are characterized by the presence in the population of both coding alleles and non-coding alleles originating from Loss-of-Function (LoF) mutations. These alleles can be found both in heterozygosity and in homozygosity in different human populations and thus represent pseudogenes that have not yet been fixed in the population. Results: A methodical cross-population analysis of 232 polymorphic pseudogenes, including 35 new examples, reveals that human olfactory signalling, drug metabolism and immunity are among the systems most impacted by the variable presence of LoF variants at high frequencies. Within this dataset, a total of 179 genes presented polymorphic LoF variants in all analysed populations. Transcriptome and proteome analysis confirmed that although these genes may harbour LoF alleles, when the coding allele is present, the gene remains active and can play a functional role in various metabolic pathways, including drug/xenobiotic metabolism and immunity. The observation that many polymorphic pseudogenes are members of multigene families argues that genetic redundancy may play a key role in compensating for the inactivation of one paralogue. Conclusions: The distribution, expression and integration of cellular/biological networks in relation to human polymorphic pseudogenes, provide novel insights into the architecture of the human genome and the dynamics of gene gain and loss with likely functional impact.

An integrative taxonomic revision of the Chaerophyllum hirsutum complex (Apiaceae) using morphological and molecular markers

Background and aims – Chaerophyllum hirsutum represents a complex of taxa with varying treatments and ranks across floras. Using both morphometric and molecular markers, we assessed the robustness of C. hirsutum, C. elegans, C. villarsii, and C. villarsii var. cicutariiforme. Material and methods – Ten morphometric variables and two ratios were calculated. Based on the sequencing of six plastomes, the rps16 intron was selected as the more variable region and sequenced on a broader sampling. Additionally, we also sequenced the nrDNA internal transcribed spacer 2 (ITS2) using Illumina technology to obtain intra-individual allelic diversity. Key results – Morphologically, the most easily differentiated taxon was C. elegans, especially using the number of subterminal umbels. The distinction between C. hirsutum and C. villarsii was rather clinal, but is mainly based on the degree of carpophore division. Finally, C. villarsii var. cicutariiforme was less easily distinguishable from the three others, but partly using the carpophore length and the total length of basal leaf blade. The cpDNArps16 clearly distinguished C. elegans from the three other taxa of the complex, which rather showed a geographical pattern of cpDNA diversity. The nrDNA ITS2 partially distinguished C. villarsii from the other taxa, without distinction of C. elegans. Conclusions – The present study supports the species differentiation of C. elegans based on both morphology and chloroplast genome. Furthermore, C. villarsii var. villarsii and C. villarsii var. cicutariiforme could potentially be recognized as distinct varieties within C. hirsutum. This will need to be confirmed by future studies using a larger sampling size and more comprehensive markers, covering a broader portion of the nuclear genome.

Units containing telomeric repeats are prevalent in subtelomeric regions of a Mesorhabditis isolate collected from the Republic of Korea.

Mesorhabditis is known for its somatic genome being only a small portion of the germline genome due to programmed DNA elimination. This phenotype may be associated with the maintenance of telomeres at the ends of fragmented somatic chromosomes. To comprehensively investigate the telomeric regions of Mesorhabditis nematodes at the sequence level, we endeavored to collect a Mesorhabditis nematode in the Republic of Korea and acquire its highly contiguous genome sequences. We isolated a Mesorhabditis nematode and assembled its 108-Mb draft genome using both 6.3Gb (53 ×) of short-read and 3.0Gb (25 × , N50 = 5.7kb) of nanopore-based long-read sequencing data. Our genome assembly exhibits comparable quality to the public genome of Mesorhabditis belari in terms of contiguity and evolutionary conserved genes. Unexpectedly, our Mesorhabditis genome has many more interstitial telomeric sequences (ITSs), specifically subtelomeric ones, compared to the genomes of Caenorhabditis elegans and M. belari. Moreover, several subtelomeric sequences containing ITSs had 4-26 homologous sequences, implying they are highly repetitive. Based on this highly repetitive nature, we hypothesize that subtelomeric ITSs might have accumulated through the action of transposable elements containing ITSs. It still remains elusive whether these ITS-containing units are associated with programmed DNA elimination, but they may facilitate new telomere formation after DNA elimination. Our genomic resources for Mesorhabditis can aid in understanding how its distinct phenotypes have evolved.

Navigating the archaeal frontier: insights and projections from bioinformatic pipelines.

Archaea continues to be one of the least investigated domains of life, and in recent years, the advent of metagenomics has led to the discovery of many new lineages at the phylum level. For the majority, only automatic genomic annotations can provide information regarding their metabolic potential and role in the environment. Here, genomic data from 2,978 archaeal genomes was used to perform automatic annotations using bioinformatics tools, alongside synteny analysis. These automatic classifications were done to assess how good these different tools perform in relation to archaeal data. Our study revealed that even with lowered cutoffs, several functional models do not capture the recently discovered archaeal diversity. Moreover, our investigation revealed that a significant portion of archaeal genomes, approximately 42%, remain uncharacterized. In comparison, within 3,235 bacterial genomes, a diverse range of unclassified proteins is obtained, with well-studied organisms like Escherichia coli having a substantially lower proportion of uncharacterized regions, ranging from <5 to 25%, and less studied lineages being comparable to archaea with the range of 35-40% of unclassified regions. Leveraging this analysis, we were able to identify metabolic protein markers, thereby providing insights into the metabolism of the archaea in our dataset. Our findings underscore a substantial gap between automatic classification tools and the comprehensive mapping of archaeal metabolism. Despite advances in computational approaches, a significant portion of archaeal genomes remains unexplored, highlighting the need for extensive experimental validation in this domain, as well as more refined annotation methods. This study contributes to a better understanding of archaeal metabolism and underscores the importance of further research in elucidating the functional potential of archaeal genomes.

Impact of Chromosomal Fusion and Transposable Elements on the Genomic Evolution and Genetic Diversity of Ilex Species.

The genus Ilex belongs to the sole family and is the single genus within the order Aquifoliales, exhibiting significant phenotypic diversity. However, the genetic differences underlying these phenotypic variations have rarely been studied. In this study, collinearity analyses of three Ilex genomes, Ilex latifolia Thunb., Ilex polyneura (Hand.-Mazz.) S. Y. Hu, and Ilex asprella Champ. ex Benth., indicated a recent fusion event contributing to the reduction of chromosomes in I. asprella. Comparative genome analyses showed slight differences in gene annotation among the three species, implying a minimal disruption of genes following chromosomal fusion in I. asprella. Comprehensive annotation of transposable elements (TEs) revealed that TEs constitute a significant portion of the Ilex genomes, with LTR transposons being predominant. TEs exhibited an inverse relationship with gene density, potentially influencing gene regulation and chromosomal architecture. TE insertions were shown to affect the conformation and binding sites of key genes such as 7-deoxyloganetin glucosyltransferase and transmembrane kinase (TMK) genes, highlighting potential functional impacts. The structural variations caused by TE insertions suggest significant roles in the evolutionary dynamics, leading to either loss or gain of gene function. This study underscores the importance of TEs in shaping the genomic landscape and evolutionary trajectories of Ilex species.

Unveiling the Genomic Symphony: Identification Cultivar-Specific Genes and Enhanced Insights on Sweet Sorghum Genomes Through Comprehensive superTranscriptomic Analysis.

Sorghum (Sorghum bicolor (L.) Moench) is a multipurpose crop grown for food, fodder, and bioenergy production. Its cultivated varieties, along with their wild counterparts, contribute to the core genetic pool. Despite the availability of several re-sequenced sorghum genomes, a variable portion of sorghum genomes is not reported during reference genome assembly and annotation. The present analysis used 223 publicly available RNA-seq datasets from seven sweet sorghum cultivars to construct superTranscriptome. This approach yielded 45,864 Representative Transcript Assemblies (RTAs) that showcased intriguing Presence/Absence Variation (PAV) across 15 published sorghum genomes. We found 301 superTranscripts were exclusive to sweet sorghum, including 58 de novo genes encoded core and linker histones, zinc finger domains, glucosyl transferases, cellulose synthase, etc. The superTranscriptome added 2,802 new protein-coding genes to the Sweet Sorghum Reference Genome (SSRG), of which 559 code for different transcription factors (TFs). Our analysis revealed that MULE-like transposases were abundant in the sweet sorghum genome and could play a hidden role in the evolution of sweet sorghum. We observed large deletions in the D locus and terminal deletions in four other NAC encoding loci in the SSRG compared to its wild progenitor (353) suggesting non-functional NAC genes contributed to trait development in sweet sorghum. Moreover, superTranscript-based methods for Differential Exon Usage (DEU) and Differential Gene Expression (DGE) analyses were more accurate than those based on the SSRG. This study demonstrates that the superTranscriptome can enhance our understanding of fundamental sorghum mechanisms, improve genome annotations, and potentially even replace the reference genome.

LncRNA H19 promoted alcohol-associated liver disease through dysregulation of alternative splicing and methionine metabolism.

Long noncoding RNAs constitute a significant portion of the human genome. Among these, lncRNA H19, initially identified for its high expression during fetal development followed by a decline in the liver postnatally, re-emerges in various liver diseases. However, its specific role in alcohol-associated liver disease (ALD) remains unclear. Elevated H19 levels were detected in peripheral blood and livers of patients with alcohol-associated cirrhosis and hepatitis, as well as in livers of ethanol-fed mice. Hepatic overexpression of H19 exacerbated ethanol-induced liver steatosis and injury. Metabolomics analysis revealed decreased methionine levels in H19-overexpressed mouse livers, attributable to H19-mediated inhibition of betaine homocysteine methyltransferase (BHMT), a crucial enzyme in methionine synthesis. H19 regulated BHMT alternative splicing through polypyrimidine tract-binding protein 1 (PTBP1), resulting in a reduced Bhmt protein-coding variant. The maternally specific knockout of H19 (H19Mat+/-) or liver-specific knockout of the H19 differentially methylated domain (H19DMDHep-/-) in ethanol-fed mice upregulated BHMT expression and ameliorated hepatic steatosis. Furthermore, BHMT restoration counteracted H19-induced ethanol-mediated hepatic steatosis. This study identifies a novel mechanism whereby H19, via PTBP1-mediated BHMT regulation, influences methionine metabolism in ALD. Targeting the H19-PTBP1-BHMT pathway may offer new therapeutic avenues for ALD.

Designing complex network visualisations using the wayfinding map metaphor

Despite their widespread use, network visualisations can be rather challenging to design and use. This is due to the fact that such visualisations are generally used to represent highly complex underlying data sets. As such, the resulting charts often include a very large number of visual elements and many non-linear relations between them that must be displayed. More effective design-oriented approaches are therefore needed to better support designers in creating network visualisations for complex data sets that are more understandable and usable for their users. The use of visual metaphors seems to offer such an approach to designing visualisations of complex data. In this article, we propose the use of wayfinding map metaphor in network diagrams to support both the designers and users of this type of data visualisation. We also provide a mapping of the three common map wayfinding tasks – orientation, exploration, and navigation – to three categories of network diagram user interactions. To demonstrate the potential of our proposed approach, we provide an example case study using a prototype network diagram visualisation tool – Colocalisation Network Explorer – which we have developed to support the exploration of relationships between various diseases and the portion of the human genome involved in their onset.

Molecular characterization and frequency of human pegivirus type 1 (HPgV-1) in kidney transplant recipients from Central-West Brazil.

Human Pegivirus Type 1 (HPgV-1), a ubiquitous commensal virus, has been recently suggested as a marker of immunologic function. There is scarce data for the presence, genotypes, and molecular characteristics of HPgV-1 among kidney transplant recipients. Therefore, the objective of this study was to examine the prevalence and the molecular characteristics (cycle threshold, genotypes) of this viral infection among kidney transplant recipients from the Brasília, Federal District of Brazil. HPgV-1 RNA detection in the plasma was assessed by RT-qPCR. Positive samples were submitted to sequencing and phylogenetic analysis of the 5´-UTR portion of the viral genome. The estimated HPgV-1 prevalence among renal-transplant recipients was 20%. The performed phylogenetic inference revealed that the most frequent genotype among these patients was HPgV-1 genotype 2 (78.9%) presented by its two subgenotypes (2A and 2B), followed by genotypes 1 and 3 (10.5% each). This study presents new data about the HPgV-1 circulation and molecular characteristics among kidney transplant recipients from the Federal District of Brazil. Further work is fundamental to examine the effect of HPgV-1 among patients with immunological suppression, including kidney transplant recipients.

Dysregulation of Transposon Transcription Profiles in Cancer Cells Resembles That of Embryonic Stem Cells.

Transposable elements (TEs) comprise a substantial portion of the mammalian genome, with potential implications for both embryonic development and cancer. This study aimed to characterize the expression profiles of TEs in embryonic stem cells (ESCs), cancer cell lines, tumor tissues, and the tumor microenvironment (TME). We observed similarities in TE expression profiles between cancer cells and ESCs, suggesting potential parallels in regulatory mechanisms. Notably, four TE RNAs (HERVH, LTR7, HERV-Fc1, HERV-Fc2) exhibited significant downregulation across cancer cell lines and tumor tissues compared to ESCs, highlighting potential roles in pluripotency regulation. The strong up-regulation of the latter two TEs (HERV-Fc1, HERV-Fc2) in ESCs has not been previously demonstrated and may be a first indication of their role in the regulation of pluripotency. Conversely, tandemly repeated sequences (MSR1, CER, ALR) showed up-regulation in cancer contexts. Moreover, a difference in TE expression was observed between the TME and the tumor bulk transcriptome, with distinct dysregulated TE profiles. Some TME-specific TEs were absent in normal tissues, predominantly belonging to LTR and L1 retrotransposon families. These findings not only shed light on the regulatory roles of TEs in both embryonic development and cancer but also suggest novel targets for anti-cancer therapy. Understanding the interplay between cancer cells and the TME at the TE level may pave the way for further research into therapeutic interventions.

Acinetobacter pittii: the emergence of a hospital-acquired pathogen analyzed from the genomic perspective.

Acinetobacter pittii has increasingly been associated with several types of hospital-acquired severe infections. Genes implicated in carbapenem resistance, tigecycline resistance, or genes encoding extended spectrum cephalosporinases, such as blaADC, are commonly found in isolates implicated in these infections. A. pittii strains that are pandrug resistant have occasionally been identified. Food for human consumption, animals and plants are environmental sources of this pathogen. An alarming situation is that A. pitti has been identified as responsible for outbreaks in different regions worldwide. In this study, 384 genomes of A. pittii were analyzed, comprising sequences from clinical and non-clinical origins from 32 countries. The objective was to investigate if clinical strains possess genetic traits facilitating hospital adaptation. Results indicate significant genomic variability in terms of size and gene content among A. pittii isolates. The core genome represents a small portion (25-36%) of each isolate's genome, while genes associated with antibiotic resistance and virulence predominantly belong to the accessory genome. Notably, antibiotic resistance genes are encoded by a diverse array of plasmids. As the core genome between environmental and hospital isolates is the same, we can assume that hospital isolates acquired ARGs due to a high selective pressure in these settings. The strain's phylogeographic distribution indicates that there is no geographical bias in the isolate distribution; isolates from different geographic regions are dispersed throughout a core genome phylogenetic tree. A single clade may include isolates from extremely distant geographical areas. Furthermore, strains isolated from the environment or animal, or plant sources frequently share the same clade as hospital isolates. Our analysis showed that the clinical isolates do not already possess specific genes, other than antibiotic-resistant genes, to thrive in the hospital setting.

Diversity and evolution of transposable elements in the plant-parasitic nematodes

BackgroundTransposable elements (TEs) are mobile DNA sequences that propagate within genomes, occupying a significant portion of eukaryotic genomes and serving as a source of genetic variation and innovation. TEs can impact genome dynamics through their repetitive nature and mobility. Nematodes are incredibly versatile organisms, capable of thriving in a wide range of environments. The plant-parasitic nematodes are able to infect nearly all vascular plants, leading to significant crop losses and management expenses worldwide. It is worth noting that plant parasitism has evolved independently at least three times within this nematode group. Furthermore, the genome size of plant-parasitic nematodes can vary substantially, spanning from 41.5 Mbp to 235 Mbp. To investigate genome size variation and evolution in plant-parasitic nematodes, TE composition, diversity, and evolution were analysed in 26 plant-parasitic nematodes from 9 distinct genera in Clade IV.ResultsInterestingly, despite certain species lacking specific types of DNA transposons or retrotransposon superfamilies, they still exhibit a diverse range of TE content. Identification of species-specific TE repertoire in nematode genomes provides a deeper understanding of genome evolution in plant-parasitic nematodes. An intriguing observation is that plant-parasitic nematodes possess extensive DNA transposons and retrotransposon insertions, including recent sightings of LTR/Gypsy and LTR/Pao superfamilies. Among them, the Gypsy superfamilies were found to encode Aspartic proteases in the plant-parasitic nematodes.ConclusionsThe study of the transposable element (TE) composition in plant-parasitic nematodes has yielded insightful discoveries. The findings revealed that certain species exhibit lineage-specific variations in their TE makeup. Discovering the species-specific TE repertoire in nematode genomes is a crucial element in understanding the evolution of genomes in plant-parasitic nematodes. It allows us to gain a deeper insight into the intricate workings of these organisms and their genetic makeup. With this knowledge, we are gaining a fundamental piece in the puzzle of understanding the evolution of these parasites. Moreover, recent transpositions have led to the acquisition of new TE superfamilies, especially Gypsy and Pao retrotransposons, further expanding the diversity of TEs in these nematodes. Significantly, the widely distributed Gypsy superfamily possesses proteases that are exclusively associated with parasitism during nematode-host interactions.These discoveries provide a deeper understanding of the TE landscape within plant-parasitic nematodes.

Unveiling the mysteries: Functional insights into hypothetical proteins from Bacteroides fragilis 638R

Humans benefit from a vast community of microorganisms in their gastrointestinal tract, known as the gut microbiota, numbering in the tens of trillions. An imbalance in the gut microbiota known as dysbiosis, can lead to changes in the metabolite profile, elevating the levels of toxins like Bacteroides fragilis toxin (BFT), colibactin, and cytolethal distending toxin. These toxins are implicated in the process of oncogenesis. However, a significant portion of the Bacteroides fragilis genome consists of functionally uncharacterized and hypothetical proteins. This study delves into the functional characterization of hypothetical proteins (HPs) encoded by the Bacteroides fragilis genome, employing a systematic in silico approach. A total of 379 HPs were subjected to a BlastP homology search against the NCBI non-redundant protein sequence database, resulting in 162 HPs devoid of identity to known proteins. CDD-Blast identified 106 HPs with functional domains, which were then annotated using Pfam, InterPro, SUPERFAMILY, SCANPROSITE, SMART, and CATH. Physicochemical properties, such as molecular weight, isoelectric point, and stability indices, were assessed for 60 HPs whose functional domains were identified by at least three of the aforementioned bioinformatic tools. Subsequently, subcellular localization analysis was examined and the gene ontology analysis revealed diverse biological processes, cellular components, and molecular functions. Remarkably, E1WPR3 was identified as a virulent and essential gene among the HPs. This study presents a comprehensive exploration of B. fragilis HPs, shedding light on their potential roles and contributing to a deeper understanding of this organism's functional landscape.

Genome Assembly of Pyrocephalus nanus: A Step Toward the Genetic Conservation of the Endangered Little Vermilion Flycatcher of the Galapagos Islands.

Incredibly powerful whole genome studies of conservation genetics, evolution, and biogeography become possible for non-model organisms when reference genomes are available. Here, we report the sequence and assembly of the whole genome of the little vermilion flycatcher (Pyrocephalus nanus; family Tyrannidae), which is an endemic, endangered, and declining species of the Galapagos Islands. Using PacBio HiFi reads to assemble long contigs and Hi-C reads for scaffolding, we assembled a genome of 1.07 Gb comprising 267 contigs in 152 scaffolds, scaffold N50 74 M, contig N50 17.8 M, with 98.9% assigned to candidate chromosomal sequences and 99.72% of the BUSCO passeriformes 10,844 single-copy orthologs present. In addition, we used the novel HiFiMiTie pipeline to fully assemble and verify all portions of the mitochondrial genome from HiFi reads, obtaining a mitogenome of 17,151 bases, containing 13 protein-coding genes, 22 tRNAs, 2 rRNAs, two control regions, and a unique structure of control region duplication and repeats. These genomes will be a critical tool for much-needed studies of phylogenetics, population genetics, biogeography, and conservation genetics of Pyrocephalus and related genera. This genome and other studies that use it will be able to provide recommendations for conservation management, taxonomic improvement, and to understand the evolution and diversification of this genus within the Galapagos Islands.

Identification and characterization of endogenous retroviruses upon SARS-CoV-2 infection.

Endogenous retroviruses (ERVs) derived from the long terminal repeat (LTR) family of transposons constitute a significant portion of the mammalian genome, with origins tracing back to ancient viral infections. Despite comprising approximately 8% of the human genome, the specific role of ERVs in the pathogenesis of COVID-19 remains unclear. In this study, we conducted a genome-wide identification of ERVs in human peripheral blood mononuclear cells (hPBMCs) and primary lung epithelial cells from monkeys and mice, both infected and uninfected with SARS-CoV-2. We identified 405, 283, and 206 significantly up-regulated transposable elements (TEs) in hPBMCs, monkeys, and mice, respectively. This included 254, 119, 68, and 28 ERVs found in hPBMCs from severe and mild COVID-19 patients, monkeys, and transgenic mice expressing the human ACE2 receptor (hACE2) and infected with SARS-CoV-2. Furthermore, analysis using the Genomic Regions Enrichment of Annotations Tool (GREAT) revealed certain parental genomic sequences of these up-regulated ERVs in COVID-19 patients may be involved in various biological processes, including histone modification and viral replication. Of particular interest, we identified 210 ERVs specifically up-regulated in the severe COVID-19 group. The genes associated with these differentially expressed ERVs were enriched in processes such as immune response activation and histone modification. HERV1_I-int: ERV1:LTR and LTR7Y: ERV1:LTR were highlighted as potential biomarkers for evaluating the severity of COVID-19. Additionally, validation of our findings using RT-qPCR in Bone Marrow-Derived Macrophages (BMDMs) from mice infected by HSV-1 and VSV provided further support to our results. This study offers insights into the expression patterns and potential roles of ERVs following viral infection, providing a valuable resource for future studies on ERVs and their interaction with SARS-CoV-2.

Genome-wide association research on the reproductive traits of Qianhua Mutton Merino sheep.

Qianhua Mutton Merino sheep is a new breed of meat wool sheep cultivated independently in China. In 2018, it was approved by the state and brought into the national list of livestock and poultry genetic resources. Qianhua Mutton Merino sheep have the common characteristics of typical meat livestock varieties with rapid growth and development in the early stage and high meat production performance. The objective of this research is to investigate the Genome-wide association of the reproductive traits of Qianhua Mutton Merino sheep. Qianhua Mutton Merino sheep from the breeding core group were selected as the research object, genome-wide association analysis was conducted on genes associated with the reproductive traits (singleton or twins, birth weight, age [in days] for sexual maturity, weaning weight, and daily gain from birth to weaning) of Qianhua mutton merino. Our study findings showed that 151 loci of single-nucleotide polymorphisms (SNPs) were detected, among which 3 SNPs related to birth weight and weaning weight occupied a significant portion of the wide genome. The candidate genes preliminarily obtained were SYNE1, SLC12A4, BMP2K, CAMK2D, IMMP2L, DMD, and BCL2. We found 151 SNP loci for five traits related to reproduction (including singleton or twins, birth weight, age [in days] at sexual maturity, weaning weight, and daily weight gain from birth to weaning). The functions of these candidate genes were mainly enriched in nucleotide metabolism, metal ion binding, oxytocin signaling pathway, and neurotrophin signaling pathway.