BMC Genomics最新文献

Low Complexity Regions (LCRs) are segments of proteins with a low diversity of amino acid composition. These regions play important roles in proteins. However, annotations describing these functions are dispersed across databases and scientific literature. LCRAnnotationsDB aims to consolidate knowledge about LCRs and store relevant annotations in a single place. To unify redundant annotations, we assigned them categories based on similarity in function, protein structure, and biological process. Categories are organized hierarchically by linking them to Gene Ontology terms. The LCRAnnotationsDB database can be accessed at https://lcrannotdb.lcr-lab.org/ .

Background: Fervidobacterium is a genus of thermophilic anaerobic Gram-negative rod-shaped bacteria belonging to the phylum Thermotogota. They can grow through fermentation on a wide range of sugars and protein-rich substrates. Some can also break down feather keratin, which has significant biotechnological potential. Fervidobacteria genomes have undergone several horizontal gene transfer events, sharing DNA with unrelated microbial taxa. Despite increasing biotechnological and evolutionary interest in this genus, only seven species have been described to date. Here, we present and describe six new and complete Fervidobacterium genomes, including the type strains Fervidobacterium gondwanense CBS-1 ^T, F. islandicum H-21 ^T and F. thailandense FC2004^T, one novel isolate from Georgia (strain GSH) and two strains (DSM 21710 and DSM 13770) that have not been previously described along with an evolutionary and phylogenomic analysis of the genus.

Results: The complete genomes were around 2 Mb with approximately 2,000 CDS identified and annotated in each of them and a G + C content ranging from 38.9 mol% to 45.8 mol%. Phylogenomic comparisons of all currently available Fervidobacterium genomes, including OrthoANI and TYGS analyses, as well as a phylogenetic analysis based on the 16S rRNA gene, identified six species and nine subspecies clusters across the genus, with a consistent topology and a distant and separately branching species, Fervidobacterium thailandense. F. thailandense harbored the highest number of transposases, CRISPR clusters, pseudo genes and horizontally transferred regions The pan genome of the genus showed that 44% of the genes belong to the cloud pangenome, with most of the singletons found also in F. thailandense.

Conclusions: The additional genome sequences described in this work and the comparison with all available Fervidobacterium genome sequences provided new insights into the evolutionary history of this genus and supported a phylogenetic reclassification. The phylogenomic results from OrthoANI and TYGS analyses revealed that F. riparium and F. gondwanense belong to the same genome species, and includes Fervidobacterium sp. 13770, while "F. pennivorans" strain DYC belongs to a separate genome species, whereas Fervidobacterium sp. 21710 and Fervidobacterium sp. GSH within the Fervidobacterium pennivorans clade represent two subspecies. F. changbaicum is reclassified as F. islandicum.

Strong and shifting selective pressures of the Anthropocene are rapidly shaping phenomes and genomes of organisms worldwide. Crops expressing pesticidal proteins from Bacillus thuringiensis (Bt) represent one major selective force on insect genomes. Here we characterize a rapid response to selection by Bt crops in a major crop pest, Helicoverpa zea. We reveal the polygenic architecture of Bt resistance evolution in H. zea and identify multiple genomic regions underlying this trait. In the genomic region of largest effect, we identified a gene amplification event, where resistant individuals showed variation in copy number for multiple genes. Signals of this amplification increased over time, consistent with the history of field-evolved Bt resistance evolution. Modern wild populations from disparate geographical regions are positive for this variant at high, but not fixed, allele frequencies. We also detected selection against single copy variants at this locus in wild H. zea collected from Bt expressing plants, further supporting its role in resistance. Multiple genes were annotated in this genomic region, and all appeared to be significantly upregulated in Bt resistant H. zea. We functionally characterized genes within the copy number variant (CNV), providing insight into their potential roles in resistance evolution. Our findings reveal the nature of rapid genome evolution in a major crop pest following anthropogenic selection and highlight the role that CNVs can have in rapid evolutionary responses.

Background: Vernicia montana and V. fordii are economically important woody oil species in the Euphorbiaceae that have great industrial oil and ornamental greening properties, however, the wild resources of Vernicia trees have been reduced because of their habitat destruction. Considering the diverse economic and ecological importance of Vernicia species, it is important to collect more molecular data to determine the genetic differences between V. montana and V. fordii.

Results: We sequenced, assembled, and annotated the complete chloroplast (CP) genome of two tung trees based on the genome skimming approach. The whole CP genomes of V. montana and V. fordii were 163,518 bp and 161,495 bp in length, both including a pair of inverted repeats separated by a large single-copy and a small single-copy region. We detected a total number of 311 tandem repeats, 100 dispersed repeats, and 255 simple repeats from V. montana and V. fordii CP genomes. The mean value of nucleotide diversity between the two species was 0.0122, and the average Ka/Ks ratio across all coding genes was 0.3483. Comparative chloroplast genome analysis showed that the coding regions were more conserved than the non-coding regions. The phylogenetic relationships yielded by the complete genome sequences showed that V. montana was closely related to V. fordii and is considered as a sister group.

Conclusions: We sequenced, assembled, annotated, and analyzed the CP genome of two tung trees, which will be useful in investigating the conservation genetics and potential breeding applications of this oil shrub.

The H3 subtype of avian influenza virus (AIV) stands out as one of the most prevalent subtypes, posing a significant threat to public health. In this study, a novel triple-reassortant H3N3 AIV designated A/chicken/China/16/2023 (H3N3), was isolated from a sick chicken in northern China. The complete genome of the isolate was determined using next-generation sequencing, and the AIV-like particles were confirmed via transmission electron microscopy. Subsequent phylogenetic analyses revealed that HA and NA genes of the H3N3 isolate clustered within the Eurasian lineage of AIVs, exhibiting the closest genetic relationship with other H3N3 AIVs identified in China during 2023. Interestingly, the HA and NA genes of the nove H3N3 isolate were originated from H3N8 and H10N3 AIVs, respectively, and the six internal genes originated from prevalent H9N2 AIVs. These findings indicated the novel H3N3 isolate possesses a complex genetic constellation, likely arising from multiple reassortment events involving H3N8, H9N2, and H10N3 subtype influenza viruses. Additionally, the presence of Q226 and T228 in the HA protein suggests the H3N3 virus preferentially binds to α-2,3-linked sialic acid receptors. The HA cleavage site motif (PEKQTR/GIF) and the absence of E627K and D701N mutations in PB2 protein classify the virus as a characteristic low pathogenicity AIV. However, several mutations in internal genes raise concerns about potential increases in viral resistance, virulence, and transmission in mammalian hosts. Overall, this study provides valuable insights into the molecular and genetic characterization of the emerging triple-reassortant H3N3 AIVs, and continued surveillance of domestic poultry is essential for monitoring the H3N3 subtype evolution and potential spread.

Background: STARR-seq and other massively-parallel reporter assays are widely used to discover functional enhancers in transfected cell models, which can be confounded by plasmid vector-induced type-I interferon immune responses and lack the multicellular environment and endogenous chromatin state of complex mammalian tissues.

Results: We describe HDI-STARR-seq, which combines STARR-seq plasmid library delivery to the liver, by hydrodynamic tail vein injection (HDI), with reporter RNA transcriptional initiation driven by a minimal Albumin promoter, which we show is essential for mouse liver STARR-seq enhancer activity assayed 7 days after HDI. Importantly, little or no vector-induced innate type-I interferon responses were observed. Comparisons of HDI-STARR-seq activity between male and female mouse livers and in livers from males treated with an activating ligand of the transcription factor (TF) CAR (Nr1i3) identified many condition-dependent enhancers linked to condition-specific gene expression. Further, thousands of active liver enhancers were identified using a high complexity STARR-seq library comprised of ~ 50,000 genomic regions released by DNase-I digestion of mouse liver nuclei. When compared to stringently inactive library sequences, the active enhancer sequences identified were highly enriched for liver open chromatin regions with activating histone marks (H3K27ac, H3K4me1, H3K4me3), were significantly closer to gene transcriptional start sites, and were significantly depleted of repressive (H3K27me3, H3K9me3) and transcribed region histone marks (H3K36me3).

Conclusion: HDI-STARR-seq offers substantial improvements over current methodologies for large scale, functional profiling of enhancers, including condition-dependent enhancers, in liver tissue in vivo, and can be adapted to characterize enhancer activities in a variety of species and tissues by selecting suitable tissue- and species-specific promoter sequences.

Background: Lablab is one of the conventionally grown multi-purpose crops that originated in Africa. It is an annual or short-lived perennial forage legume which has versatile uses (as a vegetable and dry seeds, as food or feed, or as green manure) but is yet to receive adequate research attention and hence remains underexploited. To develop new and highly productive lablab varieties, using genomics-assisted selection, the present study aimed to identify quantitative trait loci associated with agronomically important traits in lablab and to assess the stability of these traits across two different agro-ecologies in Ethiopia. Here, we resequenced one hundred and forty-two lablab accessions, utilised whole genome genotyping approaches, and conducted multi-locational phenotyping over two years.

Results: The selected lablab accessions displayed significant agro-morphological variation in eight analysed traits, including plant height, total fresh weight, and total dry weight. Furthermore, the agronomic performance of the accessions was significantly different across locations and years, highlighting substantial genotype-by-environment interactions. The population genetic structure of the lablab accessions, based on ~ 500,000 informative single nucleotide polymorphisms (SNPs), revealed an independent domestication pattern for two-seeded and four-seeded lablab accessions. Finally, based on multi-environmental trial data, a genome-wide association study (GWAS) identified useful SNPs and k-mers for key traits, such as plant height and total dry weight.

Conclusions: The publicly available genomic tools and field evaluation data from this study will offer a valuable resource for plant breeders and researchers to inform a new cycle of lablab breeding. With the aid of these tools, the breeding cycle will be significantly reduced and livestock farmers will have access to improved lablab varieties in a shorter time-frame.

Background: Amidst the escalating loss of global biodiversity, freshwater mussels (family Unionidae) have become one of the most imperiled animal groups. Acquiring more biological and phylogenetic information on understudied taxa constitutes a pivotal aspect of conservation biology. Consequently, a comprehensive examination was conducted on Koreosolenaia, Parvasolenaia, and Sinosolenaia from China encompassing morphology, anatomy, distribution, and molecular systematics to provide theoretical support for future species endangerment assessments and biodiversity conservation.

Results: The shell characteristics of Koreosolenaia, Parvasolenaia, and Sinosolenaia were clearly distinct, and the soft-body morphology could also be easily distinguished from each other. The papillae of the incurrent aperture of Sinosolenaia iridinea, Sinosolenaia recognita, and Sinosolenaia oleivora, which were previously described as difficult, exhibited significant variations that could be utilized for species diagnosis. Furthermore, both incurrent and excurrent apertures of the Sinosolenaia species had small cysts on their dorsal surfaces which may be unique to this particular group. Comparative analysis of six mitochondrial genomes (Parvasolenaia rivularis, Koreosolenaia sitgyensis, Sinosolenaia iridinea, Sinosolenaia recognita, Sinosolenaia carinata, and Sinosolenaia oleivora) revealed a completely consistent gene arrangement pattern. Additionally, there was a high consistency in nucleotide base content and skewness, amino acid usage, and relative synonymous codon usage among the six complete mitochondrial genomes. Mitochondrial phylogenomics of these genomes with additional taxa within Gonideinae robustly supported the generic relationships as follows: (Inversidens + ((Microcondylaea + Sinosolenaia) + (Parvasolenaia + (Koreosolenaia + (Ptychorhynchus + (Postolata + Cosmopseudodon)))))).

Conclusions: The present study provided significant data on the shell morphology and soft-body anatomy of Koreosolenaia, Parvasolenaia, and Sinosolenaia, thereby clarifying the diagnostic characteristics for these challenging taxa. Additionally, we established a robust phylogenetic framework at both the generic and species levels based on mitochondrial genomics.

Sweetpotato (Ipomoea batatas L.), an important food and industrial crop in the world, has a highly heterozygous hexaploid genome, making the development of single nucleotide polymorphism (SNP) markers challenging. Identifying SNP loci and developing practical SNP markers are crucial for genomic and genetic research on sweetpotato. A restriction site-associated DNA sequencing analysis of 60 sweetpotato accessions in this study yielded about 7.97 million SNPs. Notably, 954 candidate SNPs were obtained from 21,681 high-quality SNPs. Based on their stability and polymorphism, 274 kompetitive allele specific PCR (KASP) markers were then developed and uniformly distributed on chromosomes. The 274 KASP markers were used to genotype 93 sweetpotato accessions to evaluate their utility for assessing germplasm and analyzing genetic diversity and population structures. These markers had respective mean values of 0.24, 0.34, 0.31, and 0.25 for minor allele frequency, heterozygosity, gene diversity, and polymorphic information content (PIC). Their genetic pedigree led to the division of all accessions into three primary clusters, which were found to be both interrelated and independent. Finally, 74 KASP markers with PIC values greater than 0.35 were selected as core markers. These markers were used to construct the DNA fingerprints of 93 sweetpotato accessions and were able to differentiate between all accessions. To the best of our knowledge, this is the first attempt at the development and application of KASP markers in sweetpotato. However, due to sweetpotato's polyploidy, heterozygosity and the complex genome, the KASP marker conversion rate in this study was relatively low. To improve the KASP marker conversion rate, and accuracies in SNP discovery and marker validation, further studies including more accessions from underrepresented regions are needed in sweetpotato.

Background: Fat traits in cattle are considered important due to their contribution to beef eating quality and carcass economic value. Discovering the genes controlling fat traits in cattle will enable better selection of these traits, but identifying these genes in individual experiments has proven difficult. Compared to individual experiments, meta-analyses allow greater statistical power for detecting quantitative trait loci and identifying genes that influence single and multiple economically important fat traits.

Results: This meta-analysis study focussed on fat traits related to the major adipose depots in cattle (namely, carcass fat, intramuscular fat, internal fat, intermuscular fat, and subcutaneous fat) and was conducted using data from the Animal Quantitative Trait Loci (QTL) database. There were more Meta-QTL regions for intramuscular fat and subcutaneous fat (n = 158 and n = 55 regions, respectively) and far fewer for carcass fat and internal fat (n = 2 regions each). There were no Meta-QTL regions found for intermuscular fat. Of these 216 Meta-QTL regions, only 16 regions overlapped and affected two or more fat depots. The number of genes found for the fat depots was reflected in the size and number of the Meta-QTL regions (n = 20, 84, 1336 and 3853 genes for the carcass, internal, subcutaneous and intramuscular fat, respectively). The identification of these QTL allowed a more refined search for candidate genes. For example, the 232 genes in the Meta-QTL regions for carcass fat on BTA2, for intramuscular fat on BTA12, and the overlapping Meta-QTL regions on BTA2, BTA5, and BTA6 were readily screened, and 26 candidate genes were nominated based on their physiological roles using the GeneCards and DAVID databases.

Conclusions: The number of Meta-QTL regions for the various fat depots was relative to the number of associations in the database. However, the scarcity of overlapping Meta-QTL regions suggests that pleiotropic gene variants, which control multiple fat depots in cattle, are rare. The identification of candidate genes in the Meta-QTL regions will improve our knowledge of the genes with regulatory functions in adipose metabolism affecting meat quality and carcass economic value.