农学最新文献

Rice (Oryza sativa L.) is an important food crop in China. Its growth and development are threatened by rice blast, which leads to huge grain losses in severe cases. Cultivating and deploying rice varieties that contain broad-spectrum resistance (R) genes is the most economical and effective strategy to prevent and control rice blast. In general, rice blast resistance genes code nucleotide-binding (NB), leucine-rich repeat (LRR) receptors (NLRs) that play a crucial role in the resistance to rice blast. Therefore, it is essential to clone NLR genes and elucidate the recognition and activation mechanisms between NLRs and effectors for rice disease resistance breeding. In this review, we summarize and provide perspectives on the research progress of NLR genes, the recognition between NLR proteins and effectors in rice, as well as the role and mechanism of paired NLR proteins in the resistance, hoping to provide reference for rice disease resistance breeding.

Gastric cancer (GC) has a high incidence and mortality rate globally. Double minutes (DMs) are extrachromosomal circular chromosomes that carry amplified oncogenes or drug resistance genes, and they are closely associated with tumorigenesis and drug resistance. To investigate the role and regulatory mechanisms of double minutes in the malignant progression of gastric cancer, we utilize bioinformatics methods to analyze genomic copy number variation data from the CCLE cell line database and TCGA solid tumor database. We analyze and summarize the genomic features of tumor samples with double minutes. Based on these features, we classify gastric cancer samples. We use the FANTOM5 database, R package "GenomicRanges", Bedtools, and MEME SUITE to analyze the functions of the enhancers on double minutes and their regulated target genes in gastric cancer. Next, we apply the CIBERSORT package and the GDSC drug database to analyze immune cell infiltration and drug resistance in gastric cancer samples with and without double minutes from TCGA. The results show that the genome with a copy number greater than 10 and genomic fragments longer than 50 kb play a significant role. The regulatory role of double minutes enhancers affects drug resistance and tumor immunity, with disruptions in the enhancer-transcription factor-target gene regulatory loops also linked to tumor immunity. Furthermore, the target genes regulated by double minutes enhancers not only alter the expression of immune-related genes but also contribute to increased drug resistance to common chemotherapy agents in gastric cancer samples. High expression of drug resistance-related target genes in gastric cancer samples with double minutes is closely associated with poor prognosis. This study provides new insights for the treatment of gastric cancer patients with double minutes.

Reversible alterations at DNA sequence or epigenetic levels can result in phenotypes that are unstably inherited. The reversibility of these inheritable changes might be uniquely beneficial for adaption to possible fluctuations in environment. However, unstable changes are always ignored for the genetic instability in traditional studies, especially in the cause of drug resistance. In this study, we conduct a specific genetic screen in fission yeast using rapamycin (+caffeine) and obtain 173 resistant isolates. In contrast to the common strategy of isolating stable genetic mutants, we passage the cell culture with rapamycin resistance on drug free condition and test the resistance of offspring every five days, and obtain 14 strains that exhibit unstable resistance to rapamycin (the drug resistance is lost randomly among the cell progenies without drug selection pressure). Further studies show that the unstable genetic resistance of some strains is regulated by reversible DNA sequence alterationat the ssp1 gene locus. This study provides new insights and relevant scientific basis for the regulatory mechanism of unstable drug resistance in the process of rapamycin as a clinical anti-tumor drug, and a new possible target for solving the problem of drug resistance.

Ubiquitin-fold modifier 1 (FM1) is a ubiquitin-like type I protein widely present in prokaryote and most eukaryote. UFMylaiton, mediated by UFM1, is involved in the regulation of a variety of cellular biochemical processes. Recently, the importance of UFM1 system in endoplasmic reticulum homeostasis regulation has been gradually discovered and emphasized. Endoplasmic reticulum stress caused by Mycobacterium tuberculosis is an important link in the progression of tuberculosis, so UFM1 system is expected to become a new target for the development of anti-tuberculosis drugs. In this review, we provide a brief overview of the UFM1 system and UFMylation pathway, and summarize the recent advances in understanding UFM1's role in ER homeostasis regulation and its potential value in TB treatment, with the aim of offering new insight and direction for developing novel therapeutic strategies against tuberculosis.

The Ngari Prefecture is located in the western part of the Tibetan Plateau. Despite its high altitude and harsh natural environment, it occupies a strategic position adjacent to northern Nepal, India, and Ladakh. As a crossroads connecting the Tibetan Plateau, Xinjiang Autonomous Region, Central Asia, and South Asia, it likely played an important role in early human migration. Archaeological studies in recent years have revealed that even before the establishment of the Tubo Dynasty in the seventh century, the Ngari region maintained extensive cultural connections with Kashmir, Nepal, Xinjiang, and other regions. Furthermore, its subsistence economy reflected strong interactions between Ngari and northern South Asia. Recent paleogenetic studies have demonstrated that the genetic components of the ancient population in the Ngari region originated from the southern part of the plateau, with multiple population expansions occurring from south to west. These studies have also confirmed that alongside cultural exchanges, the Ngari region began experiencing complex genetic interactions with ancient populations from neighboring Central and South Asia at least 2,300 years ago. In this review, we integrate findings from paleogenetics, archaeology, archaeobotany, and zooarchaeology in the Ngari region to systematically examine the genetic origins of the ancient western plateau population and analyze both intraregional cultural-genetic interactions within the Tibetan Plateau and those between Ngari populations and external groups. This synthesis provides important insights for understanding the complex relationships between ancient population movements and interactions in the western Tibetan Plateau, as well as the transformation patterns of regional archaeological cultures and subsistence economies.

As the most thoroughly studied epigenetic modification, DNA methylation-induced silencing of suppressor genes is closely related with the development of cancers. Bioinformatic analysis is an important research tool in the fields of life sciences, medicine, and so on. To introduce the application of bioinformatic analysis in cancer epigenetic research to students and to change the current situation that students usually passively perform experiments during the experimental teaching of genetics, we established a comprehensive and exploratory epigenetic experiment which was integrated with bioinformatic analysis. The implement of this experiment followed the principles of centering on students and cultivating scientific research capabilities. Students selected the genes that were potentially silenced by high DNA methylation in lung adenocarcinoma through bioinformatic analysis and literature review under the guidance of teachers and formulated experimental scheme by their own. They then conducted real-time PCR and methylation-specific PCR to explore whether DNA methylation caused the expression silencing of genes of interest and to identify the DNA methyltransferase responsible for the methylation of genes of interest. To comprehensively assess the capability of students, we designed diversified evaluation methods which intensify the assessment of experiment process. This experiment has the characteristics of interdisciplinarity, comprehensiveness, and inquiry, which can help to cultivate the scientific thinking and practical ability of students.

Primitive hematopoiesis is a crucial process in the organism, responsible for the transportation of oxygen and nutrients during early embryonic stages and laying the foundation for the immune system. During primitive hematopoiesis, hematopoietic-related transcription factors and their cofactors interact to form a complex regulatory network that controls the process of primitive hematopoiesis. Among the bHLH transcription factor family, SCL and LYL1 are key factors in embryonic hematopoiesis. SCL is responsible for initiating primitive hematopoiesis, while LYL1, a paralog of SCL, compensates for the hematopoietic impact of SCL deficiency in adulthood. However, the role of LYL1 in primitive hematopoiesis remains unclear. This study, through analysis of zebrafish blood cell scRNA-seq data, discovered high expression of CABZ01066694.1 in hematopoietic stem/progenitor cells. Sequence alignment revealed it as a short transcript of the lyl1 gene. Subsequently, using 5'RACE and sequencing, the study confirmed the existence of both long (lyl1f) and short (lyl1s) transcripts of lyl1 in zebrafish and humans, similar to mice. Further analysis of scRNA-seq and RNA-seq data from public databases showed that in zebrafish primitive hematopoietic cells, lyl1 primarily transcribes lyl1s. Finally, using Morpholino technology to knock down lyl1f and lyl1s separately, it was found that knocking down lyl1s hindered the production of primitive myeloid progenitors and primitive granulocytes, whereas knocking down lyl1f promoted the production of primitive macrophages. In conclusion, this study demonstrates the existence of long and short transcripts of lyl1 in zebrafish and humans, with distinct roles in regulating primitive myelopoiesis, providing new insights into the regulation of primitive hematopoiesis.

MicroRNA (miRNA) is a class of single-stranded non-coding short RNA molecules about the size of 22 nt. Currently, miRNA has received the most extensive research and attention, and miRNA has been shown to be involved in the post-transcriptional regulation of gene expression in almost all cellular events, including cell proliferation, migration, differentiation, and apoptosis. miRNA plays an important role in the process of muscle regeneration by targeting key factors at different stages of skeletal muscle regeneration. In this review, we summarize the role of miRNA in regulating muscle regeneration by affecting satellite cell quiescence, myoblast proliferation, and differentiation during muscle regeneration, and update the relationship between miRNA and PI3K/AKT, TGF-β/Smad signaling during muscle regeneration. The research progress of pathway interaction will help researchers to learn more about the knowledge of miRNA in muscle regeneration biology, and provide a better understanding of the involvement of non-coding RNAs in muscle regeneration.

Apomixis is a form of asexual reproduction in plants where embryos and clone seeds are formed directly without meiosis and fertilization. The progenies generated through apomixis are genetically identical to the maternal plants, and the genotypes does not change across generations, and the phenotypes do not undergo segregation. Successful introduction of apomixis into major crops and permanent, can achieve the permanent fixation of crop heterosis, will resulting in significant economic benefits. Parthenogenesis constitutes a pivotal component in artificial apomixis, facilitating the transition from sexual reproduction to unisexual reproduction. In this review, we summarize the recent studies on plant parthenogenesis genes, and provide an overview of the application in haploid breeding and apomixis system. This contributes to a deeper and comprehensive understanding of parthenogenesis, offering important references for its application in apomixis.

Muscle fibers are the fundamental units of skeletal muscle. Based on contraction speed and metabolic properties, muscle fibers are categorized into fast-twitch and slow-twitch fibers. Further subdivision based on MyHC gene isoforms identifies them as type I, IIA, IIB, and IIX fibers. There is potential for interconversion among these muscle fiber types. The proportions of different muscle fibers determine muscle functional properties and affect muscle quality. Compared with muscles mainly harboring fast-twitch fibers, muscles predominantly composed of slow-twitch fibers are characterized by enhanced water-holding capacity, tenderness, and superior flavor. During the formation and transformation of animal skeletal muscle fibers, the expression of a series of muscle-specific genes is precisely regulated by cis-regulatory elements. These cis-regulatory elements achieve precise regulation of the target genes through interactions with transcription factors and other regulatory proteins, thereby ensuring the formation and transformation of muscle fibers. Based on introducing the types and characteristics of muscle fibers, we summarize and prospect the role of the transcription factors and cis-regulatory elements in the formation and transformation of fast-twitch and slow-twitch muscle fibers in livestock. The aim of this review is to deepen the understanding of the relationship between gene expression regulation and muscle fiber diversity, and to provide theoretical support for the improvement of meat quality in livestock.