Nucleotide Diversity Research Articles

Influenza A virus within-host evolution and positive selection in a densely sampled household cohort over three seasons.

While influenza A virus (IAV) antigenic drift has been documented globally, in experimental animal infections, and in immunocompromised hosts, positive selection has generally not been detected in acute infections. This is likely due to challenges in distinguishing selected rare mutations from sequencing error, a reliance on cross-sectional sampling, and/or the lack of formal tests of selection for individual sites. Here, we sequenced IAV populations from 346 serial, daily nasal swabs from 143 individuals collected over three influenza seasons in a household cohort. Viruses were sequenced in duplicate, and intrahost single nucleotide variants (iSNV) were identified at a 0.5% frequency threshold. Within-host populations were subject to purifying selection with >75% mutations present at <2% frequency. Children (0-5 years) had marginally higher within-host evolutionary rates than adolescents (6-18 years) and adults (>18 years, 4.4×10-6 vs. 9.42×10-7 and 3.45×10-6, p <0.001). Forty-five iSNV had evidence of parallel evolution, but were not overrepresented in HA and NA. Several increased from minority to consensus level, with strong linkage among iSNV across segments. A Wright Fisher Approximate Bayesian Computational model identified positive selection at 23/256 loci (9%) in A(H3N2) specimens and 19/176 loci (11%) in A(H1N1)pdm09 specimens, and these were infrequently found in circulation. Overall, we found that within-host IAV populations were subject to purifying selection and genetic drift, with only subtle differences across seasons, subtypes, and age strata. Positive selection was rare and inconsistently detected.

In silico analyses identify sequence contamination thresholds for Nanopore-generated SARS-CoV-2 sequences.

The SARS-CoV-2 pandemic has brought molecular biology and genomic sequencing into the public consciousness and lexicon. With an emphasis on rapid turnaround, genomic data informed both diagnostic and surveillance decisions for the current pandemic at a previously unheard-of scale. The surge in the submission of genomic data to publicly available databases proved essential as comparing different genome sequences offers a wealth of knowledge, including phylogenetic links, modes of transmission, rates of evolution, and the impact of mutations on infection and disease severity. However, the scale of the pandemic has meant that sequencing runs are rarely repeated due to limited sample material and/or the availability of sequencing resources, resulting in the upload of some imperfect runs to public repositories. As a result, it is crucial to investigate the data obtained from these imperfect runs to determine whether the results are reliable prior to depositing them in a public database. Numerous studies have identified a variety of sources of contamination in public next-generation sequencing (NGS) data as the number of NGS studies increases along with the diversity of sequencing technologies and procedures. For this study, we conducted an in silico experiment with known SARS-CoV-2 sequences produced from Oxford Nanopore Technologies sequencing to investigate the effect of contamination on lineage calls and single nucleotide variants (SNVs). A contamination threshold below which runs are expected to generate accurate lineage calls and maintain genome-relatedness and integrity was identified. Together, these findings provide a benchmark below which imperfect runs may be considered robust for reporting results to both stakeholders and public repositories and reduce the need for repeat or wasted runs.

Shared germline genomic variants in two patients with double primary gastrointestinal stromal tumours (GISTs)

BackgroundGastrointestinal stromal tumours (GISTs) are prevalent mesenchymal tumours of the gastrointestinal tract, commonly exhibiting structural variations in KIT and PDGFRA genes. While the mutational profiling of somatic tumours is well...

We are doing it wrong: Putting homology before phylogeny in cyanobacterial taxonomy.

The rapid expansion of whole genome sequencing in bacterial taxonomy has revealed deep evolutionary relationships and speciation signals, but assembly methods often miss true nucleotide diversity in the ribosomal operons. Though it lacks sufficient phylogenetic signal at the species level, the 16S ribosomal RNA gene is still much used in bacterial taxonomy. In cyanobacterial taxonomy, comparisons of 16S-23S Internal Transcribed Spacer (ITS) regions are used to bridge this information gap. Although ITS rRNA region analyses are routinely being used to identify species, researchers often do not identify orthologous operons, which leads to improper comparisons. No method for delineating orthologous operon copies from paralogous ones has been established. A new method for recognizing orthologous ribosomal operons by quantifying the conserved paired nucleotides in a helical domain of the ITS, has been developed. The D1' Index quantifies differences in the ratio of pyrimidines to purines in paired nucleotide sequences of this helix. Comparing 111 operon sequences from 89 strains of Brasilonema, four orthologous operon types were identified. Plotting D1' Index values against the length of helices produced clear separation of orthologs. Most orthologous operons in this study were observed both with and without tRNA genes present. We hypothesize that genomic rearrangement, not gene duplication, is responsible for the variation among orthologs. This new method will allow cyanobacterial taxonomists to utilize ITS rRNA region data more correctly, preventing erroneous taxonomic hypotheses. Moreover, this work could assist genomicists in identifying and preserving evident sequence variability in ribosomal operons, which is an important proxy for evolution in prokaryotes.

Comparative analysis of whole chloroplast genomes of three common species of Nekemias from vine tea

Nekemias grossedentata (N. grossedentata) is a medicinal and edible plant. The young leaves and tender stems are specifically utilized to manufacture vine tea, which is traditionally employed in the treatment of conditions such as the common cold fever, sore throat, jaundice hepatitis, and other ailments. The morphologically of N. grossedentata similar to Nekemias cantoniensis (N. cantoniensis) and Nekemias megalophylla (N. megalophylla), which lead to a chaotic market supply. Numerious studies have confirmed that chloroplast genomes and chromatography play important role in plant classification. Here, the whole chloroplast (cp) genomes of the three Nekemias species were sequenced in Illumina sequencing platform. Meanwhile, their chromatographic fingerprints have constructed using high-performance liquid chromatography (HPLC). The annotation results demonstrated that the three chloroplast genomes were typical quadripartite structures, with lengths of 162,147 bp (N. grossedentata), 161,981 bp (N. megalophylla), and 162,500 bp (N. cantoniensis), respectively. A total of 89 (N. grossedentata) /86 (N. megalophylla and N. cantoniensis) protein-coding genes, 37 tRNA gene and 8 rRNA genes were annotated. The IR/SC boundary regions were relatively conserved across the three species, although three regions (rps19-rpl2, rpl32-trnL-UAG, ccsA-ndhD) exhibited nucleotide diversity values (Pi) of variable sites higher than 1%. Phylogenetic analysis indicated that N. grossedentata had a closer genetic relationship with N. megalophylla than that of N. cantoniensis. Moreover, the chromatographic fingerprints revealed that the main functional components and genetic relatedness of three species were highly similar with their morphological results. In conclusion, N. grossedentata and N. megalophylla can be consider as the origin plants of vine tea. This study provides appropriate information for species identification, phylogeny, quality assessment of three medicinal plants of the genus Nekemias and will contribute to the standardization of vine tea raw materials.

High-resolution melting assay for rapid, simultaneous detection of JAK2, MPL and CALR variants

AimsIdentification of recurrent genetic alterations in JAK2, MPL and CALR remains crucial in the diagnosis of Philadelphia-negative myeloproliferative neoplasms (MPNs). Current laboratory testing algorithms may entail batching and/or sequential testing,...

Investigation of the Putative Functional Relevance of the IL-6 3’UTR Genetic Variants with Athletic Phenotype in Turkish Triathletes

Background/aim: Previous research suggests that genetic variants in the IL-6 gene contribute to sport-related traits and athletic performance. We aimed to identify sequence variants in the IL-6 gene region comprising the 3' untranslated region (UTR) in the Turkish triathletes and sedentary individuals and assessed their putative roles in tendency to athletic phenotype. Materials and methods: Sequence variants were identified in the Turkish triathletes (n=47) and sedentary individuals (n=46) by Sanger sequencing. Allele/genotype frequencies and linkage disequilibrium (LD) patterns were calculated by the Haploview program. The functional significance of the detected variants was analyzed using in-silico prediction tools. Results: Four single nucleotide variants (rs13306435, rs747302620, rs2069849, rs13306436) were detected in the total sample by sequencing the target region. Notably, rs13306436-3'UTR/IL-6 was only seen in the triathletes, while the exonic rs747302620 was observed in only sedentary group. Also, rs13306436G&gt;A causes loss/gain sites for binding multiple miRNAs that may be associated with athletic performance. Conclusion: Our findings indicate that the 3'UTR/IL-6 may have functional relevance in determining sports talent. Future comprehensive studies focusing on the IL-6 gene in athletes may pave the way for not only determining the athletic status of the individuals but also have implications for translational medicine.

Clinical utility of a blood based assay for the detection of IDH1.R132H-mutant gliomas

Glioma represents the most common central nervous system neoplasm in adults. Current classification scheme utilizes molecular alterations, particularly IDH1.R132H, to stratify lesions into distinct prognostic groups. Identification of the single nucleotide variant through traditional tissue biopsy assessment poses procedural risks and does not fully reflect the heterogeneous and evolving tumor landscape. Here, we introduce a liquid biopsy assay, mt-IDH1dx. The blood-based test allows minimally invasive detection of tumor-derived extracellular vesicle RNA using only 2 ml plasma volume. We perform rigorous, blinded validation testing across the study population (n = 133), comprising of IDH1.R132H patients (n = 80), IDH1 wild-type gliomas (n = 44), and age matched healthy controls (n = 9). Results from our plasma testing demonstrate an overall sensitivity of 75.0% (95% CI: 64.1%–84.0%), specificity 88.7% (95% CI: 77.0%–95.7%), positive predictive value 90.9%, and negative predictive value 70.1% compared to the tissue gold standard. In addition to fundamental diagnostic applications, the study also highlights the utility of mt-IDH1dx platform for blood-based monitoring and surveillance, offering valuable prognostic information. Finally, the optimized workflow enables rapid and efficient completion of both tumor tissue and plasma testing in under 4 hours from the time of sampling.

Whole-genome sequencing analysis reveals new susceptibility loci and structural variants associated with progressive supranuclear palsy

BackgroundProgressive supranuclear palsy (PSP) is a rare neurodegenerative disease characterized by the accumulation of aggregated tau proteins in astrocytes, neurons, and oligodendrocytes. Previous genome-wide association studies for PSP were based on genotype array, therefore, were inadequate for the analysis of rare variants as well as larger mutations, such as small insertions/deletions (indels) and structural variants (SVs).MethodIn this study, we performed whole genome sequencing (WGS) and conducted association analysis for single nucleotide variants (SNVs), indels, and SVs, in a cohort of 1,718 cases and 2,944 controls of European ancestry. Of the 1,718 PSP individuals, 1,441 were autopsy-confirmed and 277 were clinically diagnosed.ResultsOur analysis of common SNVs and indels confirmed known genetic loci at MAPT, MOBP, STX6, SLCO1A2, DUSP10, and SP1, and further uncovered novel signals in APOE, FCHO1/MAP1S, KIF13A, TRIM24, TNXB, and ELOVL1. Notably, in contrast to Alzheimer’s disease (AD), we observed the APOE ε2 allele to be the risk allele in PSP. Analysis of rare SNVs and indels identified significant association in ZNF592 and further gene network analysis identified a module of neuronal genes dysregulated in PSP. Moreover, seven common SVs associated with PSP were observed in the H1/H2 haplotype region (17q21.31) and other loci, including IGH, PCMT1, CYP2A13, and SMCP. In the H1/H2 haplotype region, there is a burden of rare deletions and duplications (P = 6.73 × 10–3) in PSP.ConclusionsThrough WGS, we significantly enhanced our understanding of the genetic basis of PSP, providing new targets for exploring disease mechanisms and therapeutic interventions.

A prognostic model constructed by ferroptosis-associated genes (FAGs) in papillary renal cell carcinoma (PRCC) and its association with tumor mutation burden (TMB) and immune infiltration.

This study aimed to identify the prognostic-related differentially expressed ferroptosis-associated genes (DEFAGs) in papillary renal cell carcinoma (PRCC). Data encompassing simple nucleotide variation, transcriptome profiles, and relevant clinical information of PRCC patients were sourced from The Cancer Genome Atlas (TCGA) database. The expression matrix of ferroptosis-associated genes (FAGs) was analyzed using the "limma" package in R to identify differentially expressed DEFAGs. Lasso regression analysis, along with univariate and multivariate Cox proportional hazards regressions, was employed to identify independent prognostic-related DEFAGs and formulate a nomogram. Additionally, we examined potential independent survival-related clinical risk factors and compared immune cell infiltration and tumor mutation burden (TMB) differences between high- and low-risk patient groups. A cohort of 321 patients were analyzed, revealing twelve FAGs significantly influencing the overall survival (OS) of PRCC patients. Among them, two mRNAs (GCLC, HSBP1) emerged as independent prognostic-related DEFAGs. Smoking status, tumor stage, and risk score were identified as independent clinical risk factors for PRCC. Furthermore, notable disparities in immune cell infiltration and function were observed between high- and low-risk groups. GCLC and HSBP1 were associated with various immune cells and functions, TMB, and immune evasion. This finding revealed two independent prognostic-related DEFAGs in PRCC and established a robust prognostic model, offering potential therapeutic targets and promising insights for the management of this disease.

Molecular Identification Validates Morphological Identification of Javanese Cardamom from Banyumas in Central Java, Indonesia

Cardamom is one of the prominent plants with significant economic value in the Banyumas Regency, Central Java, Indonesia. Although Javanese cardamom is traditionally categorized under Amomum compactum, the morphological variations observed create ambiguity about its exact species status. DNA barcoding using the maturase K (matK) and ribulose-bisphosphate carboxylase (rbcL) genes is proven as a reliable technique to elucidate the taxonomic status of morphological variable plant cultivars. This study aimed to characterize cardamom from Banyumas Regency using morphological and molecular approaches for taxonomic status identification and genetic diversity evaluation. The matK and rbcL genes were selected as genetic markers and sequenced using a bidirectional sequencing technique. Morphological examination showed significant color variations at the cardamom stem base. All samples had high genetic identities to reference species in databases and were supported by high query cover and zero e-values. Therefore, molecular characterization, alongside geographic distribution assessment, established that this plant belongs to a single species, Amomum compactum. Additionally, the analysis conducted showed a low level of genetic diversity, as evidenced by haplotype and nucleotide diversity. Low-level genetic diversity provides additional data to convince that cardamon in Banyumas Regency belongs to a single species. These results are essential data in seed selection for further cultivation.

Comprehensive analysis of the functional impact of single nucleotide variants of human CHEK2.

Loss of function mutations in the checkpoint kinase gene CHEK2 are associated with increased risk of breast and other cancers. Most of the 3,188 unique amino acid changes that can result from non-synonymous single nucleotide variants (SNVs) of CHEK2, however, have not been tested for their impact on the function of the CHEK2-enocded protein (CHK2). One successful approach to testing the function of variants has been to test for their ability to complement mutations in the yeast ortholog of CHEK2, RAD53. This approach has been used to provide functional information on over 100 CHEK2 SNVs and the results align with functional assays in human cells and known pathogenicity. Here we tested all but two of the 4,887 possible SNVs in the CHEK2 open reading frame for their ability to complement RAD53 mutants using a high throughput technique of deep mutational scanning (DMS). Among the non-synonymous changes, 770 were damaging to protein function while 2,417 were tolerated. The results correlate well with previous structure and function data and provide a first or additional functional assay for all the variants of uncertain significance identified in clinical databases. Combined, this approach can be used to help predict the pathogenicity of CHEK2 variants of uncertain significance that are found in susceptibility screening and could be applied to other cancer risk genes.

Linking watershed formation with the phylogenetic distribution of a soil microscopic fungus in Yunnan Province, China

BackgroundPhylogeographic studies have gained prominence in linking past geological events to the distribution patterns of biodiversity, primarily in mountainous regions. However, such studies often focus on plant taxa, neglecting the intricate biogeographical patterns of microbes, particularly soil microbial communities. This article explores the spatial distribution of the nematode-trapping fungus Arthrobotrys oligospora, a widespread microorganism, in a tectonically active region at the southeastern edge of the Qinghai-Tibetan Plateau. By analysing the genetic variation of this fungus alongside the historical structure of major river watersheds, we sought to uncover potential connections between the two. Our study involved sampling 149 strains from 116 sites across six major watersheds in the region.ResultsThe resulting haplotype network revealed five distinct clusters, each corresponding closely to a specific watershed. These clusters exhibited high haplotype diversity and low nucleotide diversity, supporting the notion of watershed-based segregation. Further analysis of haplotypes shared across watersheds provided evidence for three proposed past river connections. In particular, we found numerous shared haplotypes between the Yangtze and Mekong basins, as well as between the Yangtze and the Red basins. Evidence for a Irrawaddy-Salween-Red and a Yangtze-Pearl-Red river connections were also portrayed in our mapping exercise.ConclusionsThese findings emphasize the crucial role of historical geomorphological events in shaping the biogeography of microbial biodiversity, alongside contemporary biotic and abiotic factors. Watershed perimeters emerged as effective predictors of such patterns, suggesting their suitability as analytical units for regional-scale studies. Our study also demonstrates the potential of microorganisms and phylogeographic approaches to complement traditional geological analyses, providing a more comprehensive understanding of past landscape structure and its evolution.

Population genetics of two sibling species of fiddler crabs (Decapoda, Ocypodidae): Brazilian homogeneity and West Atlantic heterogeneity

Abstract Fiddler crabs are a widespread group of marine invertebrates. Their wide distribution is due to the great capacity of their larvae to disperse among estuarine and shelf waters. Therefore, it is expected that all populations along their distribution show molecular similarities due to extensive gene flow. Thus, we assessed the intra- and interspecific genetic divergence of two sibling species of fiddler crabs, Minuca panema and Minuca mordax, based on COI mtDNA sequences. The molecular data resulted in a highly mixed haplotype network for M. panema, while M. mordax sequences were clustered in two groups, one with Brazilian and other with Costa Rican haplotypes. The highest variance in M. panema was found within populations, while in M. mordax it was between groups and populations. The analyses of nucleotide divergence showed small genetic variance within populations of both species and between Brazilian populations, and higher variance between Brazilian and Costa Rican populations of M. mordax. The highest genetic divergence was found between the two species. Thereby, our results show an intense gene flow along the Brazilian coast, while there is a clear divergence among Brazil and Costa Rica, which may be a result of the great distance between these populations.

Validation of PCR diagnostic assays for detection and identification of all Ralstonia solanacearum sequevars causing Moko disease in banana.

Moko disease in banana is a bacterial wilt caused by strains within Ralstonia solanacearum sensu stricto. The disease is endemic to Central and South America but has spread to the Philippines and peninsular Malaysia. Detecting new incursions early in Moko-free banana production regions is of utmost importance for containment and eradication, as Moko management significantly increases costs of banana production. Molecular studies have supported the classification of R. solanacearum sensu stricto into phylotypes IIA, IIB and IIC, each comprising of various sequevars based on nucleotide divergence of a partial sequence within the endoglucanase gene. Moko disease in banana is caused by strains classified as sequevars 6, 24, 41, and 53 within phylotype IIA, and sequevars 3, 4, and 25 within phylotype IIB. To ensure accurate diagnostic assays are available to detect all Moko sequevars, we systematically validated previously published assays for Moko diagnostics. To be able to identify all sequevars, including the latest described sequevars, namely IIB-25, IIA-41, and IIA-53, we developed and validated two novel assays using genome-wide association studies on over 100 genomes of R. solanacearum sensu stricto. Validations using 196 bacterial isolates confirmed that a previous multiplex PCR based assay targeting sequevars IIB-3, IIB-4, IIA-6 and IIA-24 and our two novel assays targeting sequevars IIB-25, IIA-41 and IIA-53 were specific, reproducible, and accurate for Moko diagnostics.

Genomic insights into prenatal diagnosis of congenital heart defects: value of CNV-seq and WES in clinical practice.

This study aimed to assess the efficiency of CNV-seq and WES in detecting genetic cause of congenital heart disease (CHDs) in prenatal diagnoses and to compare CNV detection rate between isolated and non-isolated CHD cases. We conducted a retrospective study of 118 Chinese fetuses diagnosed with CHD by prenatal ultrasound. Participants underwent CNV-seq and, if necessary, WES to detect chromosomal and single nucleotide variations. The overall detection rate for pathogenic or likely pathogenic chromosomal abnormalities was 16.9%, including 7.6% aneuploidies and 9.3% pathogenic/likely pathogenic copy number variations (CNVs), predominantly 22q11.2 deletion syndrome (54.4%). The sensitivity and specificity of CNV-Seq for detecting P/Lp CNVs were 95% and 100%, respectively. CNV-Seq offered a 6.7% improvement in detecting chromosomal abnormalities over karyotyping. WES further identified significant single nucleotide and small indel variations contributing to CHD in genes such as TMEM67, PLD1, ANKRD11, and PNKP, enhancing diagnostic yield by 14.8% in cases negative for CNVs. Non-isolated CHD cases exhibited higher rates of detectable chromosomal abnormalities compared to isolated cases (32.4% vs. 9.9%, p = 0.005), underlining the genetic complexity of these conditions. The combined use of CNV-seq and WES provides a comprehensive approach to prenatal genetic testing for CHDs, unveiling significant genetic cause that could impact clinical management and parental decision-making. This study supports the integration of these advanced genomic technologies in routine prenatal diagnostics to increase detection diagnostic yields of causal genetic variants associated with CHDs.

Genome sequencing reveals novel causative structural and single nucleotide variants in Pakistani families with congenital hypogonadotropic hypogonadism

Background/ObjectivesThis study aims to elucidate the genetic causes of congenital hypogonadotropic hypogonadism (CHH), a rare genetic disorder resulting in GnRH deficiency, in six families from Pakistan.MethodsEighteen DNA samples from six families underwent genome sequencing followed by standard evaluation for pathogenic single nucleotide variants (SNVs) and small indels. All families were subsequently analyzed for pathogenic copy number variants (CNVs) using CoverageMaster.ResultsNovel pathogenic homozygous SNVs in known CHH genes were identified in four families: two families with variants in GNRHR, and two others harboring KISS1R variants. Subsequent investigation of CNVs in the remaining two families identified novel unique large deletions in ANOS1.ConclusionA combined, systematic analysis of single nucleotide and CNVs helps to improve the diagnostic yield for variants in patients with CHH.

Assessment of Genetic Diversity and the Population Structure of Species from the Fusarium fujikuroi Species Complex Causing Fusarium Stalk Rot of Maize.

Fusarium stalk rot (FSR), caused by the Fusarium species complex, is an economic threat to maize cultivation all over the world. We investigated the population structure and genetic diversity of Fusarium species obtained from five major maize-growing regions in India. The Tef-1α locus was used for phylogenetic analysis of geographically distinct isolates of Fusarium verticillioides, F. andiyazi, F. proliferatum, F. nygamai, and F. acutatum causing FSR. A phylogenetic tree showed monophyletic, polyphyletic, and paraphyletic groupings reflecting the complex evolutionary history and genetic diversity within the genus. Monophyletic groupings depicting strong bootstrap support were shown to have a single common ancestor and genetic coherence with limited genetic divergence among sequences. Polyphyletic groupings also presented significant genetic differentiation within the F. verticillioides sequences from diverse ecological niches. Nucleotide diversity of moderate level 0.02471 reflected genetic variations within populations that were attributed to factors such as mutation, genetic drift, or varying selection pressures. The Fst value of 0.98205 is particularly indicative of high genetic differentiation, implying that most of the genetic variance is due to differences between populations rather than within them. F. verticillioides, with 57 sequences, showed low genetic diversity with three segregating sites and a low haplotype diversity of 0.19486, suggesting the founder effect, where a reduced population expands from a limited genetic pool. The total data estimates across all populations for haplotype analysis showed 72 sequences, 44 segregating sites, and 9 haplotypes with a haplotype diversity of 0.48513. The evolutionary dynamics showed genetic differentiations among Fusarium species causing FSR. AMOVA indicated high within-population variations, depicting a substantial genetic diversity within individual populations. The results offer a comprehensive framework for discussing the implications of genetic diversity in pathogen management and the evolutionary dynamics of the Fusarium species causing FSR in maize in the Indian subcontinent.

Genomic landscape of gallbladder cancer: insights from whole exome sequencing.

Gallbladder carcinoma (GBC) is a common gastrointestinal malignancy noted for its aggressive characteristics and poor prognosis, which is mostly caused by delayed detection. However, the scarcity of information regarding somatic mutations in Indian patients with GBC has hampered the development of efficient therapeutic options. In the present study, we attempted to bridge this gap by revealing the mutational profile of GBC. To evaluate the somatic mutation profile, whole exome sequencing (WES) was performed on 66 matched tumor and blood samples from individuals with GBC. Somatic variant calling was performed using GATK pipeline. Variants were annotated at pathogenic and oncogenic levels, using ANNOVAR, VEP tools and the OncoKB database. Mutational signature analysis, oncogenic pathway analysis and cancer driver genes identification were performed at the functional level by using the maftools package. Our findings focused on the eight most altered genes with pathogenic and oncogenic mutations: TP53, SMAD4, ERBB3, KRAS, ARID1A, PIK3CA, RB1, and AXIN1. Genes with pathogenic single nucleotide variations (SNVs) were enriched in oncogenic signaling pathways, particularly RTK-RAS, WNT, and TP53 pathways. Furthermore, our research related certain mutational signatures, such as cosmic 1, cosmic 6, and cosmic 18, 29, to known characteristics including patient age and tobacco smoking, providing important insights into disease etiology. Given the scarcity of exome-based sequencing studies focusing on the Indian population, this study represents a significant step forward in providing a framework for additional in-depth mutational analysis. Genes with substantial oncogenic and pathogenic mutations are promising candidates for developing targeted mutation panels, particularly for GBC detection.

Urbanisation has impacted the population genetic structure of the Eurasian red squirrel in Japan within a short period of 30 years

Human activities often induce maladaptive effects in urban wildlife, such as increased inbreeding and decreased gene flow, consequently leading to a loss of biodiversity. Although maladaptive effects are commonly reported in urban wildlife, some wildlife species are not affected. Understanding the conditions and factors that affect the genetic structure of wildlife is crucial for its conservation in urban environments. Eurasian red squirrels Sciurus vulgaris in Obihiro City, Hokkaido, Japan, have settled in large residential lots with a high risk of vehicle collisions for approximately 30 years, raising the possibility that the urban population would be genetically isolated from nearby rural populations and may experience a rapid decrease in genetic diversity. In this study, we analysed the population structure, genetic distance, and nucleotide diversity of squirrels in the Obihiro area using genome-wide single nucleotide polymorphisms (SNPs). Principal component analysis and ADMIXTURE showed that urban and rural squirrel populations formed distinct clusters with intermediate urban and rural boundary populations. Genetic distances between the urban populations were greater than that of other pairs. Nucleotide diversities were lower in urban populations than in other populations, suggesting limited gene flow between urban and other populations, possibly due to urbanisation. The change in the genetic characteristics of urban squirrel populations during this short period demonstrates the strong impact of urbanisation. Our findings suggest that a genome-wide approach to the genetic structure of wildlife contributes to its conservation in urban environments.