Search Results (204)

This study identified four new keratin-associated protein genes (KRTAP19-n) in sheep: sKRTAP19-1, sKRTAP19-2, sKRTAP19-4, and sKRTAP19-6. These genes are closely related to the previously identified sheep genes KRTAP19-3 and KRTAP19-5, as well as to human KRTAP19-n genes. However, no clear orthologous relationships were found, suggesting complex evolutionary dynamics for this gene family. Extensive nucleotide sequence variation was observed across the four genes. sKRTAP19-1 had four variants, defined by four synonymous single-nucleotide polymorphisms (SNPs) and a variable number of “GGCTAC” hexanucleotide repeats. sKRTAP19-2 had five variants involving seven SNPs, three of which were non-synonymous. sKRTAP19-4 had five variants with nine SNPs (three being non-synonymous) and a three-nucleotide deletion. sKRTAP19-6 had eight variants, defined by 13 SNPs and a two-nucleotide consecutive substitution, with four of the SNPs being non-synonymous. One distinct variant each of sKRTAP19-4 and sKRTAP19-6 was found exclusively in Yanchi Tan sheep, with seven unique nucleotide differences compared to other variants. These unique variants were identical to the Romanov sheep genome in the region amplified (excluding the primer binding regions), suggesting a shared ancestral origin. The findings highlight considerable genetic diversity in ovine KRTAP19-n and lay a foundation for future research into their role in regulating wool fibre characteristics. Full article

T-cell receptors (TCRs) exhibit degeneracy, enabling individual TCRs to recognize multiple altered peptide ligands (APLs) derived from a single cognate antigen. This characteristic has been involved in the pathogenesis of autoimmune diseases through cross-reactivity between microbial and self-antigens. Cytotoxic T lymphocytes (CTLs), which recognize peptide–MHC class I complexes via TCRs, play a critical role in the immune response against viral infections. However, the extent to which TCR degeneracy within a population of virus-specific CTLs contributes to effective viral control remains poorly understood. In this study, we investigated the magnitude and functional relevance of TCR degeneracy in CTLs targeting an immunodominant epitope of human T-cell leukemia virus type 1 (HTLV-1) in patients with HTLV-1-associated myelopathy (HAM). Using peripheral blood mononuclear cells (PBMCs) from these patients, we quantified TCR degeneracy at the population level by comparing CTL responses to a panel of APLs with responses to the cognate epitope. Our findings demonstrated that increased TCR degeneracy, particularly at the primary TCR contact residue at position 5 of the antigen, was inversely correlated with HTLV-1 proviral load (p = 0.038, R = −0.40), despite similar functional avidity across patient-derived CTLs. Viral sequencing further revealed that CTLs with high TCR degeneracy exerted stronger selective pressure on the virus, as indicated by a higher frequency of nonsynonymous substitutions within the epitope-encoding region in patients with highly degenerate TCR repertoires. Moreover, TCR degeneracy was positively correlated with the recognition rate of epitope variants (p = 0.018, R = 0.76), suggesting that CTLs with high TCR degeneracy exhibited enhanced recognition of naturally occurring epitope variants compared to those with low TCR degeneracy. Taken together, these results suggest that virus-specific CTLs with high TCR degeneracy possess superior antiviral capacity, characterized by broadened epitope recognition and more effective suppression of HTLV-1 infection. To our knowledge, this is the first study to systematically quantify TCR degeneracy in HTLV-1-specific CTLs and evaluate its contribution to viral control in HAM patients. These findings establish TCR degeneracy as a critical determinant of antiviral efficacy and provide a novel immunological insight into the mechanisms of viral suppression in chronic HTLV-1 infection. Full article

Echovirus 30 (E-30), a member of the Enterovirus B species, is frequently linked to neurological illnesses such as aseptic meningitis, encephalitis, and hand, foot, and mouth disease. In this study, we present the complete-genome analysis of an Echovirus 30 strain isolated from cerebrospinal fluid (CSF) and stool samples of a pediatric encephalitis case in Kerala, India, during 2023. A comparative genomic investigation was carried out using a dataset of 111 human E-30 isolates, encompassing 116,991 mutation records. This analysis revealed six distinct non-synonymous amino acid substitutions uniquely present in the isolate PQ472410.1, which may be associated with pathogenicity and/or neurotropic behavior. To the best of our knowledge, this represents the first complete-genome sequence report of E-30 from an encephalitis case in India. These findings contribute valuable information to the understanding of E-30’s molecular epidemiology and evolution and offer vital data for enhancing surveillance and response strategies against enteroviral infections. Full article

This study reports the first complete mitochondrial genomes of three egg parasitoid wasps parasitizing Nilaparvata lugens—Pseudoligosita nephotetticum, Anagrus frequens, and Anagrus nilaparvatae. Genome sizes ranged from 15,429 to 15,889 bp, with all three mitogenomes displaying strong A + T bias, standard gene content, and characteristic strand asymmetries. While A. frequens and A. nilaparvatae exhibited conserved gene orders, extensive gene rearrangements, including multiple inversions in both protein-coding genes (PCGs) and tRNAs, were observed in P. nephotetticum. Codon usage analyses revealed a preference for codons ending in A or U. The non-synonymous (Ka) to synonymous (Ks) substitution ratio analysis identified signs of positive selection in multiple PCGs, particularly in atp8, nad6, and nad3, suggesting possible adaptive evolution related to host-searching behavior. Secondary structure analyses showed the loss of trnL1 in all Anagrus species, while trnS1 and trnR lacked the DHU arm, indicating possible derived traits in Mymaridae. Phylogenetic analysis was the first time to describe the relationship of the genus Anagrus within Mymaridae from the perspective of 13 protein genes. Furthermore, the grouping of (Pseudoligosita + Megaphragma) + Trichogramma was supporting the distinct evolutionary lineage of Pseudoligosita. This work provides new molecular resources and phylogenetic insight for Chalcidoidea, with implications for parasitoid evolution and biological control strategies. Full article

A male sterile mutant, S201, was identified in Brassica napus. Genetic analysis revealed that the male sterility trait was controlled by a recessive nuclear gene, male sterility (MS), which was stably inherited. The results of microscopy showed that the main reason for male sterility was a defect in microspore development, resulting in the absence of typical exine and mature microspores. Bulked segregant analysis (BSA) and genotyping of an F₂ population showed that the MS gene was located in a 1.4 Mb region. Sequence analysis showed that the CYP704B1 gene in this region contained two non-synonymous SNPs, leading to substitutions of two amino acids. A high-throughput KASP marker was characterized to detect the presence of the ms gene in the breeding population. The data presented here indicate that the male sterile mutant S201 can be applied in rapeseed breeding by producing the male sterile line and that the KASP marker developed for male sterility will be useful in marker-assisted selection of male sterile individuals in rapeseed-breeding programs. Full article

Background: Onychostoma virgulatum is an endemic freshwater fish in South China, first described as a new species in 2009. However, little is known about this species and no complete mitochondrial genomes of O. virgulatum has been reported to date. This study seeks to elucidate the characteristics of the mitochondrial genome of O. virgulatum and investigate the phylogenetic relationships within the Acrossocheilinae subfamily, particularly among the genera Onychostoma, Acrossocheilus, and Folifer. Methods: The mitochondrial genome of O. virgulatum was sequenced and assembled. We analyzed its sequence length, nucleotide composition, and evolutionary relationships within the Acrossocheilinae by incorporate data from 58 previously published mitochondrial genomes. Results: The complete circular sequence is 16,606 bp in length and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a typical control region (D-loop), all arranged in a typical order. The genomic base composition is biased toward A+T content (56.5%), with 31.4% A, 25.1% T, 27.4% C, and 16.1% G. Among about 30 Acrossocheilina species, the nonsynonymous (Ka) to synonymous substitutions (Ks) for all 13 protein-coding genes (PCGs) are significantly less than 1, suggesting strong negative or purifying selection in these species. The phylogenetic trees inferred from the mitogenome and 13 PCGs of 58 Acrossocheilinae sequences consistently indicate that: (1) O. virgulatum shares the closest genetic relationship with Onychostoma barbatulum; (2) Acrossocheilinae species are clustered into three major clades, with neither Acrossocheilus nor Onychostoma forming monophyletic groups. Conclusions: This study provides new insights into the taxonomy and phylogenetic relationships of Acrossocheilinae, particularly O. virgulatum, contributing to a better understanding of the systematics, origin, and evolution of this subfamily. Full article

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a global health challenge. The human-adapted TB-causing bacteria are distributed into ten lineages with distinct global distributions and clinical outcomes. Mtb lineages 4 (L4) and L6 are good prototypes of these differences, because L4 is globally prevalent, whereas L6 is geographically restricted to West Africa and associated with slower disease progression. Given the fundamental role of T cells for the control of TB, we questioned whether Mtb L4 or L6 antigens and HLA interactions would be disrupted in West African hosts. Here, we selected variable and validated antigens and demonstrate their expression during in vivo Mtb L4 or L6 infections. We then compared the predicted number of IFN-γ-inducing and HLA high-binding-affinity peptides in Mtb ancestral, L4, or L6 proteins, considering HLA alleles of high or low frequency in West Africa. Our immunoinformatics approach predicts that non-synonymous substitutions of high variance in Mtb L6 strains diminish binding affinities to HLA alleles prevalent in West African populations, suggesting specific adaptations of these strains to their preferred hosts. Future functional studies will advance our knowledge on lineage-specific evolution and inform strategies to enhance TB control in endemic regions. Full article

Background: Comparative studies of selection pressures on mitochondrial genomes and protein-coding genes (PCGs) are scarce in the genus Teratoscincus (Strauch, 1863), particularly within Sphaerodactylidae. Given their close evolutionary relationship, Teratoscincus przewalskii (Strauch, 1887) and Teratoscincus roborowskii (Bedriaga, 1906) serve as ideal models for the characterization of mitochondrial genome sand analysis of selective pressure in this genus. Methods: In this study, we employed Sanger sequencing to sequence the mitochondrial genome of T. roborowskii (Bedriaga, 1906), and utilized sliding window analysis, selection pressure analysis etc. to compared it with that of its close relative, T. przewalskii (Strauch, 1887). Results: The results contain the genome composition, Ka/Ks values, AT/GC-skew, etc. Selection pressure analysis of PCGs across Teratoscincus (Strauch, 1863) species (including those in GenBank) revealed that most genes evolve slowly, with the exception of ATP8 and ND6, which exhibited faster evolutionary rates. Notably, the ND6 of T. roborowskii (Bedriaga, 1906) demonstrated rapid non-synonymous substitution rates which may contribute to the survival and reproductive success of the species by favoring advantageous mutations. Phylogenetic analysis for the mitochondrial genomes of Sphaerodactylidae, Phyllodactylidae, and Gekkonidae confirmed the distinctiveness of Sphaerodactylidae and the two Teratoscincus (Strauch, 1863) species. Conclusions: This study has advanced the understanding of adaptive evolution in Teratoscincus (Strauch, 1863) mitochondrial genomes, expanded the mitochondrial database of Sphaerodactylidae, and provided insights into the phylogenetic relationships of the genus. Full article

Wheat (Triticum aestivum) is one of the most important cereal crops globally, with significant economic value. The Arabidopsis Tóxicos en Levadura (ATL) gene family, which comprises members of ubiquitin ligase enzymes (E3s), functions in substrate protein tagging during ubiquitin-mediated protein modification. Recent studies have demonstrated its involvement in stress responses. However, the ATL gene family in wheat remains poorly characterized. This study aimed to identify the members of the ATL gene family in wheat and investigate their roles under salt stress. We identified 334 TaATL genes in the wheat genome, all of which contain either RING-H2, RING U-box, or RAD18 superfamily domains, exhibiting a remarkably low proportion of intron-containing genes. The Ka/Ks (non-synonymous to synonymous substitution rate) analysis and cis-acting element analysis of the TaATL gene family indicate that its sequences are highly conserved and functionally constrained, suggesting that it may participate in abiotic stress responses through the ABA, MeJA, and MYB signaling pathways. Both RNA-seq analysis and RT-qPCR data demonstrated that the expression levels of the TaATL gene family were significantly upregulated under stress conditions, indicating their crucial roles in stress responses. This study demonstrates that the targeted regulation of stress-responsive signaling pathways mediated by superior TaATL gene family members can effectively enhance wheat salt tolerance, thereby providing a viable strategy for the development of high-yielding cultivars adapted to saline agricultural ecosystems. Full article

Maize (Zea mays L.) is a globally vital crop for food, feed, and biofuel production, with plant height (PH) being a key agronomic trait that significantly influences yield, lodging resistance, and stress tolerance. This study identified a single-base mutation in the D1 (Dwarf 1) gene responsible for the dwarf phenotype in the maize mutant 16N125. Through genetic analysis and fine mapping, the candidate region was localized to chromosome 3, narrowing it down to an interval containing three genes. Sequencing revealed a non-synonymous mutation in D1, which encodes a gibberellin 3-beta-dioxygenase, leading to amino acid substitutions at positions 61 and 123. Genetic analysis of F2 populations confirmed that the mutation at position 61 was responsible for the dwarf trait. Furthermore, the mutation was detected in several Chinese inbred lines, indicating its potential role in dwarfing under specific conditions. These findings provide critical insights into the genetic mechanisms regulating maize plant height, offering valuable information for breeding programs focused on improving crop architecture and yield to address the challenges of global food security and climate change. Full article

The pale grass blue butterfly Zizeeria maha has been used to evaluate the biological effects of the Fukushima nuclear accident in 2011. Here, we examined the DNA sequences of the mitochondrial gene cytochrome oxidase subunit I (COI) of Z. maha using the field samples collected in 2011–2014 and 2021. Among 641 individuals from 44 localities in Northeastern Japan, we detected a heteroplasmic nonsynonymous nucleotide substitution in one out of three 2012 individuals from Hirono, Fukushima Prefecture, where the biological impact of radioactive pollution was the highest among the localities surveyed in 2012, suggesting DNA damage via initial exposure to short-lived radionuclides. An additional 80 individuals from Hirono in 2021 did not show any substitution, suggesting the extinction of the Hirono mutant by 2021. We also detected another heteroplasmic and homoplasmic nonsynonymous substitution in four out of five 2014 individuals from Shibata, Niigata Prefecture, where radioactive pollution was low. These substitutions were not present in the GenBank records of Z. maha and its sister species Z. karsandra, indicating that intraspecific variation may exceed interspecific variation in Z. maha. These results highlight not only the possible impact of the initial exposure in Fukushima but also real-time molecular evolution of butterflies in the field. Full article

In plants, the R2R3-MYB transcription factors are one of the largest MYB gene families. These MYB transcription factors are very important for regulating plant growth and development. RcMYB114, RcbHLH, and RcWD40 promote anthocyanin accumulation by forming the MBW (MYB-bHLH-WD40) complex and determine the rose flower’s color. RcMYB114 genomic sequences differ between the red petal and white varieties. Two non-synonymous substitutions were found in the open reading frame. It leads to a change in amino acids. Here, the anthocyanin content showed that there was no anthocyanin in white petals, while the anthocyanin content in red petals increased firstly at stage 2, decreased slightly at stage 4, and then increased again at stage 5. The spatiotemporal expression pattern analysis showed that RcMYB114 was not expressed in all petals and tissues of white petals at different flower development stages. In red petal varieties, RcMYB114 was highly expressed in petals, followed by styles, and not expressed in stems, young leaves, and stage 1 of flower development. However, RcMYB114 has the highest expression level at the blooming stage. The RcMYB114 sequence contains 9 SNPs in the coding region, 7 of which were synonymous substitutions that had no effect on the translation product and 2 of which were non-synonymous substitutions that resulted in amino acid alteration at positions 116 and 195, respectively. The RcMYB114 gene in red rose was named RcMYB114a, and in white rose was RcMYB114b. RcMYB114c was mutated into leucine via artificial mutation; it was valine at position 116 of RcMYB114a, and Glycine mutated into Arginine at position 195 of RcMYB114a was RcMYB114d. RcMYB114b was the double mutation at positions 116 and 195 of RcMYB114a. The results of yeast two-hybrid experiments showed that RcMYB114a and its missense mutations RcMYB114b, RcMYB114c, and RcMYB114d could both interact with RcbHLH and RcWD40 to form the MYB-bHLH-WD40 complex. A transient transformation experiment in tobacco confirmed that RcMYB114a and its missense mutations RcMYB114b, RcMYB114c, and RcMYB114d could significantly promote the high expression of related structural genes in tobacco, together with the RcbHLH gene, which led to the accumulation of anthocyanins and produced the red color of the leaves. The RcMYB114a gene and its missense mutations RcMYB114b, RcMYB114c, and RcMYB114d interacted with the RcbHLH gene and significantly regulated the accumulation of anthocyanins. The two non-synonymous mutations of RcMYB114 do not affect the function of the gene itself, but the content of the anthocyanins accumulated was different. This study should provide clues and references for further research on the molecular mechanism underlying the determination of rose petal color. Full article

Background/Objectives: New anti-tuberculosis compounds are needed to treat patients infected with multi- or extensively drug-resistant Mycobacterium tuberculosis strains. Studies based on spontaneous in vitro mutagenesis can provide insights into the possible modes of action and resistance mechanisms of such new compounds. We evaluated the primary response of M. tuberculosis in vitro to the action of new aroylhydrazones and nitrofuroylamides. Methods: The reference strain H37Rv was cultured on solid media with compounds at increased concentrations relative to MIC. Resistant clones were investigated using whole-genome sequencing and bioinformatics tools to assess the role and potential impact of identified mutations. Results: Some of the mutations are significant (based on in silico analysis), located in essential genes, and therefore of particular interest. Frameshift mutations were observed in (i) Rv2702/ppgK, which is associated with starvation-induced drug tolerance and persistence in mice, and (ii) Rv3696c/glpK, which has been described as a switch on/off mutation associated with drug tolerance. Nonsynonymous substitutions were found in Rv0506/mmpS2, which belongs to the Mmp protein family involved in transport and drug efflux, and in infB, encoding the translation initiation factor IF-2. Conclusions: The primary adaptation of M. tuberculosis to the selective pressure of the tested compounds is complex and multifaceted. It involves multiple unrelated genes and pathways linked to non-specific drug tolerance, efflux systems, or mechanisms counteracting oxidative stress. Full article

Background/Objectives: Sterol regulatory element-binding transcription factor 2 (SREBF2) is a key transcription factor involved in regulating cholesterol homeostasis. However, its role in buffalo mammary gland lipid metabolism remains unclear. Methods: To address this, we isolated and characterized the SREBF2 gene from buffalo mammary glands and performed an in-depth analysis of its molecular characteristics, tissue-specific expression, and functional roles in buffalo mammary epithelial cells (BuMECs). Additionally, we investigated the single nucleotide polymorphisms (SNPs) of SREBF2 in both river and swamp buffalo. Results: The coding sequence (CDS) of buffalo SREBF2 is 3327 bp long and encodes a protein of 1108 amino acid residues. Bioinformatics analysis revealed that the molecular characteristics of buffalo SREBF2 were highly similar across Bovidae species, with collinearity being observed among them. An expression profile analysis revealed that SREBF2 is expressed in all 11 tested tissues of buffalo, with its expression level in the mammary gland being higher during lactation than in the dry period. The knockdown of SREBF2 in BuMECs during lactation led to a significant reduction in the expression of genes involved in triglyceride (TAG) and cholesterol synthesis, including PI3K, AKT, mTOR, SREBF1, PPARG, INSIG1, ACACA, SCD, DGAT1, LPL, CD36, HMGCR, and SQLE. This knockdown led to a 23.53% and 94.56% reduction in TAG and cholesterol levels in BuMECs, respectively. In addition, a total of 22 SNPs were identified in both buffalo types, of which four non-synonymous substitutions (c.301G>C, c.304A>T, c.1240G>A, and c.2944G>A) were found exclusively in the SREBF2 CDS of swamp buffalo, and the assessment revealed that these substitutions had no impact on SREBF2 function. Conclusions: These findings emphasize the critical role of SREBF2 in regulating both triglyceride and cholesterol biosynthesis, providing valuable insights into its functions in buffalo mammary glands. Full article

Idiopathic pulmonary fibrosis (IPF) has been associated with mitochondrial dysfunction. We investigated whether mitochondrial DNA variants in peripheral blood leukocytes (PBLs), which affect proteins of the respiratory chain and mitochondrial function, could be associated with an increased risk and poor prognosis of IPF. From 2020 to 2022, we recruited 36 patients (age: 75.3 ± 8.5; female: 19%) with IPF, and 80 control subjects (age: 72.3 ± 9.0; female: 27%). The mitochondrial genome of peripheral blood leukocytes was determined using next-generation sequencing. During a 45-month follow-up, 10 (28%) patients with IPF remained stable and the other 26 (72%) progressed, with 12 (33%) mortalities. IPF patients had more non-synonymous (NS) variants (substitution/deletion/insertion) in mitochondrial COX3 gene (coding for subunit 3 of complex IV of the respiratory chain), and more mitochondrial tRNA variants located in the anticodon (AC) stem, AC loop, variable loop, T-arm, and T-loop of the tRNA clover-leaf structure in PBLs than the control group. The succumbed IPF patients were older, had lower initial diffusion capacity, and higher initial fibrosis score on high-resolution computerized tomography (HRCT) than the alive group. NS variants in mitochondrial COX3 gene and tRNA variants in PBLs were associated with shorter survival. Our study shows that (1) leukocyte mitochondrial COX3 NS variants are associated with risk and prognosis of IPF; (2) leukocyte mitochondrial tRNA variants located in the AC stem, AC loop, variable loop, T-arm, and T-loop of the tRNA clover-leaf structure are associated with risk, and the presence of tRNA variants is associated with poor prognosis of IPF. Full article