Genome最新文献

The worldwide salinization of freshwater ecosystems poses a major threat to the biodiversity, functioning and services that these essential ecosystems provide. We are far from fully understanding the ecological and evolutionary consequences of salinization for freshwater organisms. Here we review current research on the genomic responses to salinity in freshwater zooplankton. Surveying transcriptomic studies, we identify many key ion transport genes critical for osmoregulation of ions in multiple zooplankton species in response to salinity stress. Laboratory investigations of natural zooplankton populations inhabiting gradients of salinity often reveal additional candidate genes that are not identified in gene expression experiments (e.g., trehalose). We suggest that future studies should focus on genomic approaches to explore the molecular mechanisms of adaptation to freshwater salinization in zooplanktons, and to predict the eco-evolutionary consequences of freshwater salinization.

Luteinizing hormone-releasing hormone A3 (LHRH-A3), a reproductive hormone analog, is widely used to stimulate ovulation in female rabbits. However, the long-term impact of sustained LHRH-A3 administration on the reproductive system, particularly ovarian health, remains unclear. In this study, we compared apoptosis levels in ovaries and molecular regulation between LHRH-A3-treated (A3 group) and untreated female rabbits (N group) after their 5th litter. Western blotting showed a significantly lower Bcl-2/Bax ratio in the A3 group compared with the N group (P < 0.01), indicating higher ovarian apoptosis. Ovarian tissues from four rabbits per group were divided into the A3 group and the N group, and RNA-seq technology was then utilized to conduct transcriptome analysis on these two groups. This analysis revealed 220 differentially expressed genes (DEGs), including BMP6, BMP15, CYP1A1, and other reproductive-related genes. KEGG analysis of these DEGs showed their involvement in processes such as the cell cycle, PI3K-Akt signaling pathway, and ovarian steroidogenesis. Subsequently, we selected the key gene Matrix metallopeptidase 7 (MMP7) for functional analysis using CCK8 and Annexin V-FITC/PI techniques. MMP7 was found to promote the proliferation of granulosa cells (GCs) and inhibit apoptosis (P < 0.01). In conclusion, LHRH-A3 treatment can modulate ovarian molecular regulation, with the key gene MMP7 involved in the proliferation and apoptosis of GCs.

Successful resistance to disease-causing pathogens is underpinned by properly regulated immune signalling and defence responses in plants. The plant immune system is controlled at multiple levels of gene and protein regulation-from chromatin-associated epigenetic processes to protein post-translational modifications. Optimal fine-tuning of plant immune signalling and responses is important to prevent plant disease development, which is being exacerbated by a globally changing climate. In this review, we focus on how changing climatic factors mechanistically intercept plant immunity at different levels of regulation (chromatin, transcriptional, post-transcriptional, translational, and post-translational). We specifically highlight recent studies that have provided molecular insights into critically important climate-sensitive nodes and mechanisms of the plant immune system. We then propose several potential future directions to build climate-resilient plant disease resistance using cutting-edge biotechnology. Overall, this conceptual understanding and promising biotechnological advances provide a foundational platform towards novel approaches to engineer plant immune resilience.

This review explores the challenges and potential solutions in plant micropropagation and biotechnology. While these techniques have proven successful for many species, certain plants or tissues are recalcitrant and do not respond as desired, limiting the application of these technologies due to unattainable or minimal in vitro regeneration rates. Indeed, traditional in vitro culture techniques may fail to induce organogenesis or somatic embryogenesis in some plants, leading to classification as in vitro recalcitrance. This paper focuses on recalcitrance to somatic embryogenesis due to its promise for regenerating juvenile propagules and applications in biotechnology. Specifically, this paper will focus on epigenetic factors that regulate recalcitrance as understanding them may help overcome these barriers. Transformation recalcitrance is also addressed, with strategies proposed to improve transformation frequency. The paper concludes with a review of CRISPR-mediated genome editing's potential in modifying somatic embryogenesis-related epigenetic status and strategies for addressing transformation recalcitrance.

Crop breeding, which relies on the presence and/or generation of alterations in DNA, has been essential to the development of agricultural production. Such breeding endeavours are carried out using a wide range of methods, which have diversified immensely over the years as our understanding of genetics has grown. While this expansion in our breeding "toolbox" has provided vast improvements in the specificity, pace and effectiveness of crop trait enhancement, apprehension surrounding the use of biotechnological breeding platforms in particular led countries to develop costly and lengthy regulatory processes for plants deemed to be "genetically modified" as a means of managing safety concerns and assuaging public unease. In this article, we discuss crop regulatory policies in Canada and beyond, in the context of transgenic crops, as well as those developed using newer biotechnological breeding platforms such as gene editing. We also examine the benefits of biotechnologically bred crops, and consider the broader socio-economic, ethical, and environmental impacts of overly restrictive regulatory frameworks, which could very feasibly limit the prospect of food security in the future.

Anthrax, caused by the bacterial pathogen Bacillus anthracis, is a lethal disease affecting both livestock and humans. This study focused on the comparative whole-genome analysis of two Indian virulent Bacillus anthracis strains recovered from anthrax cases in cattle (NIVEDIAX3) and sheep (NIVEDIAX61), and their comparison with available genomes (n = 55) in the NCBI database. Phylogenetic analysis based on average nucleotide identity clustered the 57 strains into 3 groups, with both NIVEDIAX strains grouped under Cluster II, alongside the Ames Ancestor strain. Multilocus sequence typing (MLST) assigned the strains to Bacillus cereus sequence type ST1, Bacillus anthracis core genome MLST ST284, and Bacillus anthracis plasmid ST12 based on typing scheme. A total of 5217 orthologous clusters and 468 single-copy gene clusters shared between the NIVEDIAX strains and the Ames Ancestor strain were identified. Canonical single nucleotide polymorphism (canSNP) analysis classified both strains as A.Br.003 (A.Br.Aust94 sub-lineage). Further, analysis of the 57 Bacillus anthracis genomes revealed that A.Br.003 was the most prevalent canSNP among animal isolates. In India, multiple Bacillus anthracis sub-lineages have been reported. In conclusion, the circulation of diverse Bacillus anthracis sub-lineages in livestock across Southern and Eastern states of India, was noted.

Traditional taxonomic revisions based on macromorphological and leaf anatomical traits may have limitations in accurately distinguishing certain species within the genus. To improve taxonomic clarity, this study applied DNA barcoding to enhance the understanding of the taxonomy and phylogeny of Baccaurea Lour., a plant genus widely utilized for food, medicine, and building materials. DNA barcode regions, including rbcL, ITS2, and trnH-psbA, were used to analyze 64 samples representing 19 Baccaurea species. Using similarity Basic Local Alignment Search Tool and phylogenetic tree inference, we determined the discriminatory efficiencies of rbcL, ITS2, trnH-psbA, and their combinations rbcL + ITS2 and rbcL + ITS2 + trnH-psbA as 21.1%, 89.5%, 87.5%, 89.5%, and 89.5%, respectively. The Neighbor-Joining tree revealed well-defined, monophyletic species clusters that largely align with phylogenetic positions based on macromorphological features. Notably, our results indicate that Baccaurea parviflora and the synonymized Baccaurea scortechinii are distinct species, recommending the re-establishment of B. scortechinii as a separate species. DNA barcoding is useful in delineating species boundaries, facilitating routine specimen identification, and flagging atypical samples for detailed examination.

Platycarya longipes is a dominant tree species in karst forests. Due to limited genomic information, its exact phylogenetic position within the family Juglandaceae remains unclear. In this study, the complete chloroplast genome (cp genome) of Platycarya longipes was de novo assembled using Illumina reads. This circular cp genome was 158 592 bp in length, consisting of an 88 066 bp large single-copy region, an 18 524 bp small single-copy region, and a total of 26 001 bp derived from a pair of inverted repeats (IRa and IRb), with an average GC content of 36.15%. It accommodated a total of 113 genes, including 80 protein-coding genes, 29 tRNAs, and 4 rRNAs. Additionally, within the genome, 49 long repeats and 66 simple sequence repeats, which could be utilized as molecular markers, were identified. In comparison to the related Platycarya strobilacea, the K_a/K_s substitution rate values of Platycarya longipes exhibited significant divergence, supporting the differentiation between the species. The conserved gene order and structure of the Platycarya longipes cp genome compared to other Juglandaceae members. Phylogenetic analysis using maximum likelihood and Bayesian inference methods with Fagales genomes showed a close relationship between Platycarya longipes and Platycarya strobilacea.

Benzo(a)pyrene produced by food during high-temperature process enters the body through ingestion, which causes food safety issues to the human body. To alleviate the harm of foodborne benzo(a)pyrene to human health, a strain that can degrade benzo(a)pyrene was screened from Kefir, a traditional fermented product in Xinjiang. Bacillus cereus M72-4 is a Gram-positive bacteria sourced from Xinjiang traditional fermented product Kefir; under benzo(a)pyrene stress conditions, there was 69.39% degradation rate of 20 mg/L benzo(a)pyrene by strain M72-4 after incubation for 72 h. The whole genome of M72-4 was sequenced using PacBio sequencing technology in this study. The genome size was 5754 801 bp and a GC content was 35.24%; a total of 5719 coding genes were predicted bioinformatically. Through functional database annotation, it was found that the strain has a total of 219 genes involved in the transportation and metabolism of hydrocarbons, a total of 9 metabolic pathways related to the degradation and metabolism of exogenous substances, and a total of 67 coding genes. According to the Kyoto Encyclopedia of Genes and Genomes database annotation results, a key enzyme related to benzo(a)pyrene degradation, catechol 2,3-dioxygenase, was detected in the genome data of Bacillus cereus M72-4, encoding genes dmpB and xylE, respectively. There are also monooxygenases and dehydrogenases. Therefore, it can be inferred that this strain mainly degrades benzo(a)pyrene through benzoate metabolic.