Cytosine Content Research Articles

Genome assembly of a potential probiotic Bifidobacterium bifidum BB11 strain isolated from Holstein calves.

Here we report the genome sequence of Bifidobacterium bifidum BB11 strain, isolated from the Holstein bull calf's rumen samples. The strain tested positive for probiotic characteristics such as bile salt tolerance, adhesion, and acid tolerance. The genome size was 2,200,000 bp with the guanine and cytosine (G+C) content of 62.5%.

A tip of the iceberg: genome survey indicated a complex evolutionary history of Garuga Roxb. species

Background Garuga Roxb. is a genus endemic to southwest China and other tropical regions in Southeast Asia facing risk of extinction due to the loss of tropical forests and changes in land use. Conducting a genome survey of G. forrestii contribute to a deeper understanding and conservation of the genus.ResultsThis study utilized genome survey of G. forrestii generated approximately 54.56 GB of sequence data, with approximately 112 × coverage. K-mer analysis indicated a genome size of approximately 0.48 GB, smaller than 0.52GB estimated by flow cytometry. The heterozygosity is of about 0.54%, and a repeat rate of around 51.54%. All the shotgun data were assembled into 339,729 scaffolds, with an N50 of 17,344 bp. The average content of guanine and cytosine was approximately 35.16%. A total of 330,999 SSRs were detected, with mononucleotide repeats being the most abundant at 70.16%, followed by dinucleotide repeats at 20.40%. We conducted a preliminary ploidy assessment using Smudgeplot and observed a clear bimodal distribution in G. forrestii at 1/2 relative coverage depth and total coverage depth (2n), suggesting a potential diploid genome structure. A pseudo chromosome of G. forrestii and a gemone of Boswellia sacra were used as reference genome to perform a primer population resequencing analysis within three Garuga species. Principal component analysis (PCA) indicated three distinct groups, but genome wide phylogenetics represented conflicting both between the dataset of different reference genomes and between maternal and nuclear genome.ConclusionIn summary, the genome of G. forrestii is small, and the phylogenetic relationships within the Garuga genus are complex. The genetic data presented in this study holds significant value for comprehensive whole-genome analyses, the evaluation of population genetic diversity, investigations into adaptive evolution, the advancement of artificial breeding efforts, and the support of species conservation and restoration initiatives. Ultimately, this research contributes to reinforcing the conservation and management of natural ecosystems, promoting biodiversity conservation, and advancing sustainable development.

Genome-wide DNA methylation and their transgenerational pattern differ in Arabidopsis thaliana populations originated along the elevation of West Himalaya

Methylation at 5' cytosine of DNA molecule is an important epigenetic mark. It is known to play critical role in adaptation of organisms under different biotic and abiotic stressors via modulating gene expression and/or chromatin architecture. Plant populations evolved under variable climatic conditions may have evolved different epigenetic marks including DNA methylation. Here we, describe the genome-wide DNA methylation pattern under native field, F1 and F6 generation followed by their association with phenotypes, climate and global gene expression in the three Arabidopsis thaliana populations originated at different elevation ranges of Indian West Himalaya. We show that the global methyl cytosine (mC) content is more or less similar in the three populations but differ in their distribution across genome. There was an increase in differential methylation between the populations as elevation increased. The methylation divergence was the highest between the low and the high elevation populations. The high elevation populations were hypo-methylated than the low elevation population. The methylation in the genes was associated with population specific phenotypes and climate of the region. The genes which were differentially methylated as well as differentially expressed between the low and high elevation populations were mostly related to abiotic stresses. When grown under controlled condition, there was gain of differential methylation over native condition and the maximum percent changes was observed in CHH-sequence context. Further ~ 99.8% methylated cytosines were stably passed on from F1 to F6 generation. Overall, our data suggest that high elevation population is epigenetically more plastic under changing environmental condition.BackgroundArabidopsis thaliana is the model plant species and has been extensively studied to understand plants life processes. There are numerous reports on its origin, demography, evolution, epigenomes and adaptation etc. however, Indian populations of Arabidopsis thaliana evolved along wide elevation ranging from ~ 700 m amsl to ~ 3400 m amsl not explored yet. Here we, describe the genome-wide DNA methylation pattern under native field, F1 and F6 generation followed by their association with phenotypes, climate and global gene expression in the three Arabidopsis thaliana populations originated at different elevation ranges of Indian West Himalaya.Results In our study we found that total mCs percent was more or less similar in the three populations but differ in their distribution across genome. The proportion of CG-mCs was the highest, followed by CHH-mCs and CHG-mCs in all the three populations. Under native field condition the methylation divergence was more prominent between low and high elevation populations and the high elevation populations were hypo-methylated than the low elevation population. The methylation in the genes was linked to population-specific phenotypes and the regional climate. The genes that showed differential methylation and expression between low and high elevation populations were primarily associated with abiotic stress responses. When grown under controlled condition, there was gain of differential methylation compared to the native condition and the maximum percent changes was observed in CHH-sequence context. Further 99.8% methylated cytosines were stably passed on from F1 to F6 generation.Conclusions The populations of A. thaliana adapted at different climatic conditions were significantly differentially methylated both under native and controlled condition. However, the magnitude and extent of gain or loss of methylation were most significant between the low and the high elevation populations. Overall, our data suggest that high elevation population is epigenetically more plastic under changing environmental condition.

Enhancing RNA-seq bias mitigation with the Gaussian self-benchmarking framework: towards unbiased sequencing data

BackgroundRNA sequencing is a vital technique for analyzing RNA behavior in cells, but it often suffers from various biases that distort the data. Traditional methods to address these biases are typically empirical and handle them individually, limiting their effectiveness. Our study introduces the Gaussian Self-Benchmarking (GSB) framework, a novel approach that leverages the natural distribution patterns of guanine (G) and cytosine (C) content in RNA to mitigate multiple biases simultaneously. This method is grounded in a theoretical model, organizing k-mers based on their GC content and applying a Gaussian model for alignment to ensure empirical sequencing data closely match their theoretical distribution.ResultsThe GSB framework demonstrated superior performance in mitigating sequencing biases compared to existing methods. Testing with synthetic RNA constructs and real human samples showed that the GSB approach not only addresses individual biases more effectively but also manages co-existing biases jointly. The framework’s reliance on accurately pre-determined parameters like mean and standard deviation of GC content distribution allows for a more precise representation of RNA samples. This results in improved accuracy and reliability of RNA sequencing data, enhancing our understanding of RNA behavior in health and disease.ConclusionsThe GSB framework presents a significant advancement in RNA sequencing analysis by providing a well-validated, multi-bias mitigation strategy. It functions independently from previously identified dataset flaws and sets a new standard for unbiased RNA sequencing results. This development enhances the reliability of RNA studies, broadening the potential for scientific breakthroughs in medicine and biology, particularly in genetic disease research and the development of targeted treatments.

The adaptive evolution of Quercus section Ilex using the chloroplast genomes of two threatened species

Chloroplast (cp) genome sequences have been extensively used for phylogenetic and evolutionary analyses, as many have been sequenced in recent years. Identification of Quercus is challenging because many species overlap phenotypically owing to interspecific hybridization, introgression, and incomplete lineage sorting. Therefore, we wanted to gain a better understanding of this genus at the level of the maternally inherited chloroplast genome. Here, we sequenced, assembled, and annotated the cp genomes of the threatened Quercus marlipoensis (160,995 bp) and Q. kingiana (161,167 bp), and mined these genomes for repeat sequences and codon usage bias. Comparative genomic analyses, phylogenomics, and selection pressure analysis were also performed in these two threatened species along with other species of Quercus. We found that the guanine and cytosine content of the two cp genomes were similar. All 131 annotated genes, including 86 protein-coding genes, 37 transfer RNA genes, and 8 ribosomal RNA genes, had the same order in the two species. A strong A/T bias was detected in the base composition of simple sequence repeats. Among the 59 synonymous codons, the codon usage pattern of the cp genomes in these two species was more inclined toward the A/U ending. Comparative genomic analyses indicated that the cp genomes of Quercus section Ilex are highly conserved. We detected eight highly variable regions that could be used as molecular markers for species identification. The cp genome structure was consistent and different within and among the sections of Quercus. The phylogenetic analysis showed that section Ilex was not monophyletic and was divided into two groups, which were respectively nested with section Cerris and section Cyclobalanopsis. The two threatened species sequenced in this study were grouped into the section Cyclobalanopsis. In conclusion, the analyses of cp genomes of Q. marlipoensis and Q. kingiana promote further study of the taxonomy, phylogeny and evolution of these two threatened species and Quercus.

Complete genome sequence of Edwardsiella tarda strain GBS0709 isolated from a Japanese patient with the acute motor axonal neuropathy subtype of Guillain-Barré syndrome.

The complete genome sequence of Edwardsiella tarda strain GBS0709, isolated from an 81-year-old Japanese patient with the acute motor axonal neuropathy subtype of Guillain-Barré syndrome, was determined. It comprised a 3,632,068 bp circular chromosome and a 5,386 bp plasmid. The overall guanine and cytosine content was 57.3%.

Complete genome sequence of candidate probiotic Limosilactobacillus fermentum KUFM407.

It has been reported that the administration of Limosilactobacillus fermentum alleviates diseases such as osteoporosis and colitis. In this study, we report the complete genome sequence of Limosilactobacillus fermentum KUFM407, a probiotic strain of LAB isolated from Korean traditional fermented food, Kimchi. Whole genome sequencing of L. fermentum KUFM407 was performed on the Illumina MiSeq and Oxford Nanopore MinION platform. The genome consisted of one circular chromosome (2,077,616 base pair [bp]) with a guanine cytosine (GC) content of 51.5% and one circular plasmid sequence (13,931 bp). Genome annotation identified 1,932 protein-coding genes, 15 rRNAs, and 58 tRNAs in the assembly. The function annotation of the predicted proteins revealed genes involved in the biosynthesis of bacteriocin and fatty acids. The complete genome of L. fermentum KUFM407 could provide valuable information for the development of new probiotic food and health supplements.

A molecular beacon design for a colorimetric loop-mediated isothermal amplification assay.

In this study, a molecular beacon (MB) was designed for colorimetric loop-mediated isothermal amplification (cLAMP). The length of complementary bases on the MB, guanine and cytosine content (GC content), and hybridization sites of complementary bases were investigated as key factors affecting the design of the MB. We designed MBs consisting of 10, 15, and 20 complementary bases located at both ends of the HRPzyme. In the case of the long dumbbell DNA structure amplified from the hlyA gene of Listeria monocytogenes, possessing a flat region (F1c-B1) of 61base pairs (bp), an MB was designed to intercalate into the flat region between the F1c and B1 regions of the LAMP amplicons. In the case of the short dumbbell DNA structure amplified from the bcfD gene of Salmonella species possessing a flat region (F1c-B1) length of 6bp, another MB was designed to intercalate into the LoopF or LoopB regions of the LAMP amplicons. The results revealed that the hybridization site of the MB on the LAMP amplicons was not crucial in designing the MB, but the GC content was an important factor. The highest hybridization efficiencies for LAMP amplicons were obtained from hlyA gene-specific and bcfD gene-specific MBs containing 20- and 15-base complementary sequences, respectively, which exhibited the highest GC content. Therefore, designing MBs with a high GC content is an effective solution to overcome the low hybridization efficiency of cLAMP assays. The results obtained can be used as primary data for designing MBs to improve cLAMP accessibility.

Characterization and Phylogenetic Analyses of the Complete Chloroplast Genome Sequence in Arachis Species

Characterization and Phylogenetic Analyses of the Complete Chloroplast Genome Sequence in Arachis Species

Complete Genome and Comprehensive Analysis of Knorringia sibirica Chloroplast

Knorringia sibirica is a typical species of Polygonaceae with high medicinal and ecological value. However, there are few available phylogenetic and genetic studies about the chloroplast genome of K. sibirica. In the current study, a comprehensive examination of the chloroplast genome of K. sibirica was performed. The K. sibirica chloroplast genome is 161,384 bp, circular with a typical quadripartite structure, and comprised of guanine + cytosine content of 37.63%. The genome consists of 131 genes, including 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Seventy simple sequence repeats were identified in the genome. When compared with three closely related species, the result revealed that the chloroplast genome of K. sibirica was conserved in genome composition and structure. The specific sites in the genome suitable for DNA barcodes were identified by calculation of the nucleotide diversity. Finally, a phylogenetic tree of 49 species in Polygonaceae was constructed using the whole chloroplast genome. The phylogenetic analysis suggested that Knorringia is an independent genus in the Polygonea tribe. This research could provide support for the utilization of genetic sources and the evolutionary study of K. sibirica.

Complete genome sequence of Enterococcus faecium strain AK_C_05 with potential characteristics applicable in livestock industry.

The Enterococcus faecium (E. faecium) strain AK_C_05 was isolated from cheonggukjang, the Korean traditional food, collected from a local market in South Korea. In this report, we presented the complete genome sequence of E. faecium strain AK_C_05. The genome of E. faecium strain AK_C_05 genome consisted of one circular chromosome (2,691,319 bp) with a guanine + cytosine (GC) content of 38.3% and one circular plasmid (177,732 bp) with a GC content of 35.48%. The Annotation results revealed 2,827 protein-coding sequences (CDSs), 18 rRNAs, and 68 tRNA genes. It possesses genes, which encodes enzymes such as alpha-galactosidase (EC 3.2.1.22), beta-glucosidase (EC 3.2.1.21) and alpha-L-arabinofuranosidase (EC 3.2.1.55) enabling efficient utilization of carbohydrates. Based on Clusters of Orthologous Groups analysis, E. faecium strain AK_C_05 showed specialization in carbohydrate transport and metabolism indicating the ability to generate energy using a variety of carbohydrates.

Complete Chloroplast Genomes of Four Oaks from the Section Cyclobalanopsis Improve the Phylogenetic Analysis and Understanding of Evolutionary Processes in the Genus Quercus.

Quercus is a valuable genus ecologically, economically, and culturally. They are keystone species in many ecosystems. Species delimitation and phylogenetic studies of this genus are difficult owing to frequent hybridization. With an increasing number of genetic resources, we will gain a deeper understanding of this genus. In the present study, we collected four Quercus section Cyclobalanopsis species (Q. poilanei, Q. helferiana, Q. camusiae, and Q. semiserrata) distributed in Southeast Asia and sequenced their complete genomes. Following analysis, we compared the results with those of other species in the genus Quercus. These four chloroplast genomes ranged from 160,784 bp (Q. poilanei) to 161,632 bp (Q. camusiae) in length, with an overall guanine and cytosine (GC) content of 36.9%. Their chloroplast genomic organization and order, as well as their GC content, were similar to those of other Quercus species. We identified seven regions with relatively high variability (rps16, ndhk, accD, ycf1, psbZ-trnG-GCC, rbcL-accD, and rpl32-trnL-UAG) which could potentially serve as plastid markers for further taxonomic and phylogenetic studies within Quercus. Our phylogenetic tree supported the idea that the genus Quercus forms two well-differentiated lineages (corresponding to the subgenera Quercus and Cerris). Of the three sections in the subgenus Cerris, the section Ilex was split into two clusters, each nested in the other two sections. Moreover, Q. camusiae and Q. semiserrata detected in this study diverged first in the section Cyclobalanopsis and mixed with Q. engleriana in the section Ilex. In particular, 11 protein coding genes (atpF, ndhA, ndhD, ndhF, ndhK, petB, petD, rbcL, rpl22, ycf1, and ycf3) were subjected to positive selection pressure. Overall, this study enriches the chloroplast genome resources of Quercus, which will facilitate further analyses of phylogenetic relationships in this ecologically important tree genus.

Effects of host-associated low-temperature probiotics in olive flounder (Paralichthys olivaceus) aquaculture

This study investigated the effects of supplementation of low-temperature probiotics isolated from the intestines of olive flounder on the growth performance, digestibility, and regulation of intestinal microbiota and the expression of genes related to growth, immunity, and apoptosis in olive flounder. Bacteria showing high growth at approximately 15–20 °C, which is the temperature of olive flounder culture, were isolated and confirmed to be Pseudomonas species through 16S rRNA gene sequence analysis. Whole-genome sequencing revealed that the strain has a 6,195,122 bp single circular chromosome and a guanine–cytosine content of 59.9%. In the feeding trial, supplementation with 1 × 108 CFU/g of the isolate strain positively modulated growth performances, digestive enzyme activity, and gut microbiota composition of olive flounder. RT-qPCR for the comparison of growth, immunity, and apoptosis-related gene expression levels showed no significant differences between the groups. Therefore, the isolated host-associated low-temperature probiotics improved the growth performance of olive flounder by causing positive changes in digestive activity and intestinal microbial composition without affecting host gene expression.

Genome-Based in silico Evaluation of the Biosafety and Probiotic Traits of Limosilactobacillus fermentum J23 Isolated from Artisanal Mexican Cheese

ABSTRACT Comprehensive in silico analysis aimed to identify the genes involved in the biosafety and probiotic features of Limosilactobacillus fermentum J23 was performed. The strain had a single circular chromosome of 2,004,882 base pairs (bp), with a Guanine + Cytosine (G + C) content of 51.74%. The chromosome contained 2,001 genes predicted as protein-coding sequences (CDS), 86 pseudogenes, 56 tRNAs, five rRNAs, and three ncRNAs. The in silico analysis demonstrated the absence of risk-related genes corresponding to transferable/acquirable antibiotic resistance, virulence factors, toxic metabolites, and detrimental metabolic/enzymatic activities. The strain was predicted as nonpathogenic to humans and the presence of a variety of genes potentially related to its probiotic profile were revealed, including those of carbohydrate metabolism and transport, adhesion and aggregation ability, stress/adaptive response, CRISPR/Cas adaptive immunity, and immunomodulation. These findings highlight the probiotic potential of L. fermentum J23 and provide genomic clues of its biosafety to advance its future applications.

The complete chloroplast genome of the neo-allotetraploid fern, Asplenium pseudocapillipes S.H.Park et al. (Aspleniaceae)

This study analyzed the complete plastome sequence of the neo-allotetraploid Asplenium pseudocapillipes S.H.Park et al. Asplenium pseudocapillipes has a typical circular plastome that comprises 157,242 bp with a large single copy (84,105 bp), a small single copy (21,503 bp), and two inverted repeats (IRs; 25,817 bp). The complete sequence comprises 127 genes, including 87 protein-coding genes (CDSs), eight ribosomal RNAs (rRNAs), 31 transfer RNAs (tRNAs), and one pseudogene. Among these genes, five CDSs, four rRNAs, and five tRNAs are duplicated in IRs. The guanine–cytosine content of the genome was 41.5%. The enlarged noncoding regions by Mobile Open Reading Frames in Fern Organelles were found once in other Asplenium species and twice in A. pseudocapillipes. Phylogenetic analysis based on 83 coding gene sequences revealed that A. pseudocapillipes is embedded in the A. varians subclade along with its progenitors.

Complete genome sequence of bacteriocin-producing Ligilactobacillus salivarius B4311 isolated from fecal samples of broiler chicken with anti-listeria activity.

Ligilactobacillus is a genus of Gram-positive lactobacilli commonly found in the intestinal tracts of vertebrates. It has been granted a Qualified Presumption of Safety (QPS) status from the European Food Safety Authority (EFSA). One specific strain, Ligilactobacillus salivarius B4311, was isolated from fecal samples of broiler chickens from a farm associated with Chung-Ang University (Anseong, Korea). This strain was observed to have inhibitory effects against Listeria monocytogenes. In this paper, we present the complete genome sequence of Lig. salivarius B4311. The whole genome of strain B4311 comprises 2,071,255 bp assembled into 3 contigs representing a chromosome, repA-type megaplasmid, and small plasmid. The genome contains 1,963 protein-coding sequences, 22 rRNA genes, and 78 tRNA genes, with a guanine + cytosine (GC) content of 33.1%. The megaplasmid of strain B4311 was found to contain the bacteriocin gene cluster for salivaricin P, a two-peptide bacteriocin belonging to class IIb.

Method for Quantitative HDV RNA Detection: I, Manual Workflow (Serum and Liver Tissue) and II, Fully Automated High Throughput Workflow for Diagnostic Use.

The hepatitis delta virus (HDV) is a small RNA virus (1700 base pairs), which uses the surface proteins of the hepatitis B virus (HBV) as an envelope. Accurate and reliable quantitative detection of HDV RNA is central for scientific and translational clinical research or diagnostic purposes. However, HDV poses challenges for nucleic acid amplification techniques: (1) the circular genome displays high intramolecular base pairing; (2) high content of cytosine and guanine; and (3) enormous genomic diversity among the eight known HDV genotypes (GTs). Here, we provide step-by-step instructions for (A) a manual workflow to perform a quantitative HDV reverse transcription (RT)-PCR from serum and liver tissue and (B) a quantitative HDV RT-PCR assay with whole process control to be used for serum or plasma samples run on a fully automated system. Both assays target the conserved ribozyme region and demonstrate inclusivity for all eight HDV GTs. The choice of assay depends on the experimental needs and equipment availability. While the former is ideal for scientific research laboratories, the latter provides a useful tool in the field of translational research or diagnostics.

Association between SPRY1 and TET3 in skin photoaging and natural aging mechanisms.

SPRY1 is associated with the invasiveness and prognosis of various tumors, and TET3 affects aging by regulating gene expression. We investigated the roles of SPRY1 and TET3 in natural skin aging, replicative aging, and photoaging, along with the effect of UVA on genome-wide DNA methylation in HaCaT cells. TET3 and SPRY1 expression were measured in the skin of patients of different age groups, as well as invitro human skin, HaCaT cell replicative senescence, and HaCaT and HaCaT-siTET3 cell photoaging models. Senescence was verified using β-galactosidase staining, and DNA damage was detected using immunofluorescence staining for γ-H2A.X. 5-Methyl cytosine (5-mC) content in the genome was determined using ELISA. SPRY1 expression increased with age, whereas TET3 expression decreased. Similarly, SPRY1 was upregulated and TET3 was downregulated with increasing cell passages. TET3-siRNA upregulated SPRY1 expression in HaCaT cells. UVA irradiation promoted HaCaT cell senescence and induced cellular DNA damage. SPRY1 was upregulated and TET3 was downregulated upon UVA irradiation. Genome-wide 5-mC content increased upon TET3 silencing and UVA irradiation, indicating a surge in overall methylation. SPRY1 and TET3 are natural skin aging-related genes that counteract to regulate replicative aging and UVA-induced photoaging in HaCaT cells. The cell photoaging model may limit experimental bias caused by different exposure times of skin model samples.

Tuning gene expression by hairpin elements near the start codon of mRNA in mammalian cells

The hairpin element (HpE) near the start codon in the 5′ untranslated region (UTR) was developed to tune the mRNA translation in mammalian cells. The parameters of HpEs including thermodynamic stability, the content of guanine and cytosine, and distance between HpEs and the 5′ cap were investigated. These parameters influenced the mRNA expression level. In addition, the start codon and the upstream open reading frame sequestered within the structures of HpEs also reduced the translation initiation. In summary, this study shows that the simple engineering HpE structure can be efficiently adopted for gene expression regulation. The predictable controllability of this simple cloning strategy can potentially achieve precise gene expression regulation in different mammalian cell types.

Complete genome and two plasmids sequences of Lactiplantibacillus plantarum L55 for probiotic potentials.

In this study, we report the complete genome sequence of Lactiplantibacillus plantarum L55, a probiotic strain of lactic acid bacteria isolated from kimchi. The genome consists of one circular chromosome (2,077,416 base pair [bp]) with a guanine cytosine (GC) content of 44.5%, and two circular plasmid sequences (54,267 and 19,592 bp, respectively). We also conducted a comprehensive analysis of the genome, which identified the presence of functional genes, genomic islands, and antibiotic-resistance genes. The genome sequence data presented in this study provide insights into the genetic basis of L. plantarum L55, which could be beneficial for the future development of probiotic applications.