农学最新文献

As a canonical non-B DNA secondary structure, the G-quadruplex (G4) dynamically regulates core biological processes, including telomere homeostasis, DNA replication and gene transcription/translation-through its unique four-stranded conformation. The significant enrichment of G4 structures in regulatory regions, particularly promoter regions within mammalian genomes reveals their critical role in transcriptional regulation. In this review, we focus on the dynamic formation mechanisms and transcriptional regulatory functions of endogenous G4 structures, systematically elucidating their three molecular pathways in modulating gene expression: (1) orchestrating spatial assembly of transcription activation complexes; (2) dynamically regulating epigenetic modifications, includinghistone alterations and DNA methylation; (3) remodeling three-dimensional chromatin architecture to establish transcriptionally active microenvironments. By integrating advancements in G4 topological characterization techniques and dynamic equilibrium networks, this work highlights the role of the G4 as a critical cis-regulatory element and provides a theoretical framework for developing G4-targeted therapeutic strategies.

Mitochondria, as crucial organelles within eukaryotic cells, have their proteins and RNAs encoded by both the nuclear genome and the mitochondrial genome. They play vital roles in energy regulation, cellular metabolism, signal transduction, and various other physiological activities. Additionally, mitochondria interact with multiple organelles to collectively maintain cellular homeostasis. Mitochondria can also be transferred between cells and tissues through mechanisms such as migrasomes. Mitochondrial DNA (mtDNA) mutations often cause severe inherited rare diseases, characterized by tissue specificity, heterogeneity, multiple mutation sites, and challenges in achieving a complete cure. Gene editing of mtDNA holds promise for fundamentally curing such diseases. Traditional gene-editing nucleases, such as zinc-finger nucleases (ZFNs) and transcription activator-like effector nuclease (TALENs), as well as novel gene editors like DddA-derived cytosine base editors (DdCBEs), have been demonstrated to correct certain mtDNA mutations. However, CRISPR-based technologies-despite their superior programmability and efficiency-are currently limited due to the technical bottleneck of inefficient sgRNA delivery into mitochondria. This article systematically reviews the structure and function of mitochondria, related diseases, and the current state of mtDNA gene-editing therapies. Furthermore, it explores future directions for optimizing therapeutic tools to overcome the challenge of sgRNA delivery, thereby addressing the treatment barriers posed by pathogenic mtDNA mutations in inherited rare diseases.

Given the inherent complexity, hierarchical organization, and dynamic nature of living systems, there is no single best strategy for investigation, and priorities shift with the evolution of the life sciences. In the 1990s, two classic stories, The Salvation of Doug and The Demise of Bill, used automobiles as analogies and satire to contrast two research strategies: dismantling components to uncover underlying mechanisms, or applying functional perturbations to identify critical elements. These heuristic parables stimulated broad discussion on the respective strengths and limitations of different research approaches and continue to be widely used in teaching today. The life sciences have since entered an era integrating high-throughput, high-resolution, and multidimensional approaches, where single-path strategies can no longer provide deep, systematic insights into complex biological processes. We view the intrinsic features of living systems, such as modular organization, regulatory networks, nonlinear responses, and adaptive compensation, as factors that make any single approach likely to capture only local, static aspects, thereby hindering the reconstruction of systems-level, dynamic properties. Against this backdrop, we present a modern continuation of the two parables, reimagined in a contemporary setting and featuring two protagonists with symbolic Chinese names, "Zhiwei" (meaning "decoding hidden mechanisms") and "Sixu" ("reasoning through order"), who personify biochemical and genetic mindsets. In our narrative, the two protagonists transition from working independently to collaborating, integrating high-throughput experimentation, systems-level analysis, and computational modeling to uncover structural and operational principles underlying complex systems. We believe this retelling reflects the growing emphasis on systems-level and dynamic perspectives in biology, highlighting the value of methodological integration and innovation. We hope it will serve as a valuable resource for teaching in genetics and related disciplines, while fostering reflection on the enduring relevance of genetic reasoning in contemporary research.

The medicinal preparation of Chilobrachys jingzhao possesses various therapeutic properties, including anti-inflammatory, detoxifying, analgesic, and anti-edema effects. However, research on its genetic background and toxin mechanisms is held back by the lack of chromosome karyotype and genome data. In this study, we analyzed the karyotype of C. jingzhao using chromosome preparation techniques, estimated the genome size using flow cytometry and K-mer analysis, and performed genome sequencing and assembly using second- and third-generation single molecule real-time sequencing technologies. The results showed that C. jingzhao has a diploid chromosome number of 2n=68, with a karyotype formula of 2n=46m+18sm+4st and a chromosomal complement of 2n=10L+18M2+38M1+2S. Using Solanum lycopersicum and Trichonephila clavata as references, flow cytometry estimates the genome size at 7,775.49 Mb and 7,680.26 Mb, respectively. The 19-mer analysis also estimated the genome size to be 7,626.00 Mb, consistent with the flow cytometry results. Further analysis indicated that the genome of C. jingzhao has a high level of heterozygosity (8.45%) and a high proportion of repetitive sequences (67.10%), classifying it as an ultra-high heterozygous and high-repeat genome. The initial genome assembly of C. jingzhao was 8,804.93 Mb in size, with a contig N50 of 55.55 Mb and a BUSCO completeness score of 95.9%, indicating high assembly quality. This study first reveals the karyotype and genome information of C. jingzhao, offering crucial data for future research on its whole genome, toxin mechanisms, genetics, origin, evolution, and taxonomy.