Gene Family Research Articles

Genome-wide identification and characterization of bZIP gene family explore the responses of PsebZIP44 and PsebZIP46 in Pseudoroegneria libanotica under drought stress.

The fundamental leucine zipper (bZIP) genes play a crucial role as transcriptional coactivators in plants. Pseudoroegneria libanotica served as the maternal contributor to several species within the tribe Triticeae (Poaceae), exhibiting commendable resilience to various stressors. Consequently, bZIP genes of Pseudoroegneria libanotica response to abiotic stresses was important for further understanding of stress tolerance studies in Triticeae. A total of 108 PsebZIPs were identified in this study, and they were divided into 10 subgroups. PsebZIPs were found to be extensively involved in the biological activities within P. libanotica. The RNA-seq results revealed differential responses of PsebZIPs to drought stress in both aerial and root tissues. PsebZIP44 and PsebZIP46 were regarded as potential genes capable of responding to abiotic stress, and their varying degrees of responsiveness to drought, salinity, heavy metals, heat, and oxidative stress have been demonstrated in yeast. Homologous proteins with intact bZIP gene structures of PsebZIP44 or PsebZIP46 have not been identified in wheat. The current investigation not only provides a fundamental basis for further probing into the biological functions of PsebZIPs within P. libanotica but also reveals previously undiscovered potential genes with the ability to respond to abiotic stress. They could contribute to improving the genetic constitution of Triticeae crops, including wheat.

Deciphering the anthocyanin metabolism gene network in tea plant (Camellia sinensis) through structural equation modeling.

Tea is an important cash crop that significantly contributes to rural development, poverty reduction and food security in many developing countries. It provides livelihoods for millions of smallholder producers and aids their economic stability. Anthocyanins in tea leaves provides excellent commercial quality and germplasm exploration potential. These compounds give tea leaves vibrant colors and increase health benefits. The current understanding of the synergistic regulation mechanisms responsible for color changes in purple tea, attributed to anthocyanin degradation, remains unclear. In this study, we have identified 30 gene families within the genome that are associated to with anthocyanin metabolism from tea. These gene families play distinct roles in the biosynthesis of anthocyanin including the formation of the core, structure, modification of the molecular framework, facilitation of transport process, regulation of gene expression, breakdown pathways, sugar transportation and iron ion respectively. Subsequently, we investigated the synergistic mechanisms of anthocyanin metabolism related gene families within tea leaves using structural equation modeling. The results showed that sugar transport positively affects anthocyanin transportation, and promotes anthocyanin degradation during leaf pigmentation, whereas, it inhibits anthocyanin degradation during the fading of leaf color. Further, Iron ions facilitate the degradation of anthocyanins during their deposition and conversely, impede this degradation process during digestion. These finding suggests that tea plants may regulate the synthesis and degradation of anthocyanins through sugar transport and iron ions ensure healthy levels and vibrant colors. Our study contributes valuable information into the dynamic equilibrium anthocyanin mechanism and sheds light on complex regulatory mechanisms that govern the synthesis, transport and degradation of these pigments. These insights could be further used to develop strategies for enhancing anthocyanins content in unique tea germplasm to aid tea industry in producing new tea products with increased health benefits and aesthetic appeals.

Genome-wide identification, transcript profiling and functional analyses of PCP gene family in Wucai (Brassica campestris).

Pollen coat proteins (PCPs) are cysteine-rich small-molecule proteins, which exhibit high levels of polymorphism and are expressed in gametocytes. Previous investigations have revealed that PCP genes are involved in pollen wall synthesis, pollen-stigma recognition, and pollen development and germination. However, gene expression and function of PCP family in pollen development is not well understood in Wucai (Brassica campestris L.). In this study, genome-wide identification and expression analysis of the BcPCP gene family members were conducted, including their physical and chemical properties, chromosome localization, phylogenetic relationships, gene structure, and tertiary structure. A total of 20 BcPCP genes were identified and classified into three subfamilies showing high homology to Arabidopsis thaliana. Expression pattern analysis indicated that the BcPCP gene family exhibits higher expression levels in reproductive organs, suggesting their potential involvement in the reproductive development. Notably, BraA02g002400.3C, potentially associated with male sterility, was identified through multiple transcriptomic and proteomic datasets. Subsequently, sequence analysis revealed its homology with the Arabidopsis GRP20 gene, and thus it was named BcGRP20. Functional analysis of this gene showed that overexpression of BcGRP20 gene in the Arabidopsis grp20 mutant could restore anther fertility. Overall, our findings indicate that BcGRP20 plays a critical role in pollen development and may be the causative gene for male sterility in Wucai. This study provides candidate genes for further functional identification of BcPCP genes in Wucai, which are crucial for anther development.

Genome-based analysis of biosynthetic potential from antimycotic Streptomyces rochei strain A144.

Streptomyces rochei is a species of Streptomyces with a diverse range of biological activities. S. rochei strain A144 was isolated from desert soils and exhibits antagonistic activity against several plant pathogenic fungi. The genome of S. rochei A144 was sequenced and revealed the presence of one linear chromosome and one plasmid. The chromosome length was found to be 8,085,429bp, with a GC content of 72.62%, while the Plas1 length was 177,399bp, with a GC content of 69.08%. Comparative genomics was employed to analyse the S. rochei group. There is a high degree of collinearity between the genomes of S. rochei strains. Based on pan-genome analysis, S. rochei has 10,315 gene families, including 4051 core and 2322 unique genes. AntiSMASH was used to identify the gene clusters for secondary metabolites, identifying 33 secondary metabolite genes on the A144 genome. Among them, 18 clusters were found to be >70% identical to known biosynthetic gene clusters (BGCs), indicating that A144 has the potential to synthesize secondary metabolites. The majority of the BGCs were found to be conserved within the S. rochei group, including those encoding polyketide synthases (PKS), terpenes, non-ribosomal peptide synthetases (NRPS), other ribosomally synthesised and post-translationally modified peptides (RiPP), nicotianamine-iron transporters, lanthipeptides, and a few other types. The S. rochei group can be a potential genetic source of useful secondary metabolites with applications in medicine and biotechnology.

Genome-Wide Identification of GRAS Gene Family in Cunninghamia lanceolata and Expression Pattern Analysis of ClDELLA Protein Under Abiotic Stresses

The Chinese fir (Cunninghamia lanceolata) is a significant species utilized in afforestation efforts in southern China. It is distinguished by its rapid growth and adaptability to diverse environmental conditions. The GRAS gene family comprises a group of plant-specific transcription factors that play a pivotal role in plant growth and development, response to adversity, and hormone regulatory networks. However, the exploration of the GRAS family in gymnosperm Chinese fir has not yet begun. In this study, a total of 43 GRAS genes were identified in the whole genome of Chinese fir, and a phylogenetic analysis classified them into nine distinct subfamilies. Gene structure analysis revealed that the majority of ClGRAS genes lacked introns. It is notable that among these proteins, both ClGAI and ClGRA possess distinctive DELLA structural domains. Cis-acting element analysis revealed that nearly all ClGRAS genes contained light-responsive elements, while hormone-responsive elements, environmental-responsive elements (low-temperature- or defense-responsive elements), and meristem-organization-related elements were also identified. Based on transcriptome data and RT-qPCR expression patterns, we analyzed the expression of ClGAI and ClRGA genes across different developmental stages, hormones, and three abiotic stresses. Subcellular localization analysis demonstrated that ClGAI and ClRGA were localized to the nucleus. Transcriptional activation assays showed that both genes have self-activating activity. In conclusion, the results of this study indicate that the ClGRAS gene family is involved in the response of Chinese fir to environmental stress. Further research on the ClDELLA genes provides valuable information for exploring the potential regulatory network of DELLA proteins in Chinese fir.

Whole-Genome Sequence and Characterization of Ralstonia solanacearum MLY102 Isolated from Infected Tobacco Stalks

Background/Objectives: Bacterial wilt disease is a soil-borne disease caused by Ralstonia solanacearum that causes huge losses to crop economies worldwide. Methods: In this work, strain MLY102 was isolated and further identified as R. solanacearum from a diseased tobacco stalk. The genomic properties of MLY102 were explored by performing biochemical characterization, genome sequencing, compositional analysis, functional annotation and comparative genomic analysis. Results: MLY102 had a pinkish-red color in the center of the colony surrounded by a milky-white liquid with fluidity on TTC medium. The biochemical results revealed that MLY102 can utilize carbon sources, including D-glucose (dGLU), cane sugar (SAC) and D-trehalose dihydrate (dTRE). Genome sequencing through the DNBSEQ and PacBio platforms revealed a genome size of 5.72 Mb with a G+C content of 67.59%. The genome consists of a circular chromosome and a circular giant plasmid with 5283 protein-coding genes. A comparison of the genomes revealed that MLY102 is closely related to GMI1000 and CMR15 but has 498 special genes and 13 homologous genes in the species-specific gene family, indicating a high degree of genomic uniqueness. Conclusions: The unique characteristics and genomic data of MLY102 can provide important reference values for the prevention and control of bacterial wilt disease.

Exploring the driver events of eccrine poromas and porocarcinomas: A retrospective, cross-institutional study of 54 cases.

We have comprehensively characterised the mutational landscape of eccrine poroma (EP) and eccine porocarcinoma (EPC), uncovering novel events and delineating different pathways of tumorigenesis underlying these tumours. EPs are driven largely by oncogenic fusion genes, whereas EPCs are driven largely by somatic mutations affecting various pathways, with a subset driven by fusion genes as the first oncogenic driver, and somatic mutations representing secondary events contributing to progression of the tumour. Fusion genes in EP predominantly involve YAP1 whereas those in EPC preferentially involve PAK gene family members.

ABC Family Gene Polymorphisms and Cognitive Functions Interact to Influence Antidepressant Efficacy.

The importance of identifying relevant indicators of antidepressant efficacy is highlighted by the low response rates to antidepressant treatment for depression. The ABC gene family, encoding ATP-dependent transport proteins facilitating the transport of psychotropic drugs, has drawn attention. This study delved into the relationship between antidepressant efficacy and seven single nucleotide polymorphisms of ABCB1 and ABCB6 genes. A total of 549 depressed patients participated in the study, and all completed a 6-week course of antidepressant treatment. Cognitive function was assessed at baseline and post-treatment. Patients were categorized based on post-treatment HAMD-17 scores (with HAMD≤7 indicating remission), and comparisons were made between different groups in terms of allelic gene frequencies and genotypes. Logistic regression was used to explore the interaction between cognitive function and genotype on efficacy. Dual-luciferase reporter assays were performed to compare the regulatory effects of rs1109866 allele variants on the ABCB6 promoter. There were no notable differences in allelic gene frequencies and genotypes between the remission and non-remission groups. Nonetheless, a significant interaction was identified between the rs1109866 genotype and language fluency-related indicators concerning efficacy (p=0.029) before correction. The dual-luciferase reporter assays demonstrated markedly higher fluorescence intensity of rs1109866-C compared to that of rs1109866-T (p<0.001). Relying solely on genetic polymorphisms of ABC family genes as predictors of antidepressant treatment response may not be sufficient. However, the interaction between the rs1109866 and cognition plays a pivotal role. The potentially enhanced transcriptional activity of rs1109866-C might offer insight into its impact on antidepressant efficacy.

A conserved sequence that sparked the field of evo-devo.

The discovery that homeotic genes in Drosophila are conserved and utilized for embryonic development throughout the animal kingdom, including humans, revolutionized the fields of developmental biology and evolutionary developmental biology (evo-devo). In a pair of back-to-back papers published in Cell in 1984, researchers at the Biozentrum in Basel, Switzerland, showed that the homeobox - previously identified as a sequence shared by homeotic genes in Drosophila - was also present in the genome of diverse animals. The first paper (McGinnis et al., 1984a) showed that genomes of both invertebrates and vertebrates contain sequences that cross-hybridized with Drosophila homeobox probes. The second paper (Carrasco et al., 1984) identified a cross-hybridizing sequence in the model system Xenopus laevis. They then isolated the first vertebrate homeobox-containing gene by cloning and sequencing of the corresponding genomic region. Finally, they showed that this gene (AC1, later renamed HoxC6) was expressed during embryonic development, the first evidence that developmentally expressed Drosophila genes could be used to isolate regulators of vertebrate embryonic development. These findings led to a flurry of activity in the evo-devo field, initially focused on isolating Hox genes across diverse species, and then expanding to isolation of other gene families based on Drosophila orthologs, an approach that continues today. This led to the notion of a conserved genetic toolkit for embryonic development, currently accepted, but unexpected at the time of its discovery. We attempt to provide some context for the sea-change in thinking that these discoveries brought about by referring to Jean Piaget's theories about the sequential acquisition of scientific knowledge.

Molecular characterization of Pleiotropic Drug Resistance (PDR) genes involved in tolerance of cadmium in peanut (Arachis hypogaea L.).

Peanut (Arachis hypogaea L.) is one of the most important oil crops worldwide. Cadmium (Cd), a heavy metal that is nonessential and toxic, has the potential to significantly impacted the quality and safety of peanut. Despite the known importance of Pleiotropic Drug Resistance (PDR) genes in heavy metal accumulation and transport in plants, there is a lack of comprehensive research on the systematic identification and functional characterization of AhPDRs in peanut. In this study, a total of 38 AhPDR genes were discovered within the peanut genome. Among these, AhPDR24, AhPDR30, and AhPDR33 displayed notable variations in expression levels in response to Cd stress. Particularly noteworthy was the observation that AhPDR33, localized in the plasma membrane, exhibited a significant increase in expression (approximately 3.8-fold) and heightened promoter activity (approximately 4.1-fold) following exposure to Cd (75 μM CdCl2). Furthermore, the study found that the overexpression of AhPDR33 in Arabidopsis resulted in increased root elongation and decreased Cd accumulation (approximately 0.42-fold) compared to wild-type plants. This suggests that AhPDR33 may have a beneficial role in facilitating Cd efflux and tolerance in plants. Additionally, transient silencing of AhPDR33 in peanut demonstrated its positive regulation of Cd tolerance through the promotion of reactive oxygen species (ROS) scavenging and membrane permeability reduction. These findings contribute to the understanding of the molecular mechanisms involved in AhPDR33-mediated Cd tolerance and detoxification in peanut. Furthermore, this study provides comprehensive information to understand the AhPDR gene family, its features, and its expression, which will hold a promising utility as an excellent candidate in the genetic improvement of peanut Cd stress tolerance.

Pan-genome wide identification and analysis of the SAMS gene family in sunflowers (Helianthus annuus L.) revealed their intraspecies diversity and potential roles in abiotic stress tolerance

IntroductionS-adenosylmethionine (SAM), a key molecule in plant biology, plays an essential role in stress response and growth regulation. Despite its importance, the SAM synthetase (SAMS) gene family in sunflowers (Helianthus annuus L.) remains poorly understood.MethodsIn this study, the SAMS genes were identified from the sunflower genome. Subsequently, the protein properties, gene structure, chromosomal location, cis-acting elements, collinearity, and phylogeny of the SAMS gene family were analyzed by bioinformatic methods. Finally, the expression patterns of SAMS genes in different tissues, under different hormonal treatment and abiotic stress were analyzed based on transcriptome data and qRT-PCR.ResultsThis study identified 58 SAMS genes across nine cultivated sunflower species, which were phylogenetically classified into seven distinct subgroups. Physicochemical properties and gene structure analysis showed that the SAMS genes are tightly conserved between cultivars. Collinearity analysis revealed segmental duplications as the primary driver of gene family expansion. The codon usage bias analysis suggested that natural selection substantially shapes the codon usage patterns of sunflower SAMS genes, with a bias for G/C-ending high-frequency codons, particularly encoding glycine, leucine, and arginine. Analysis of the cis-regulatory elements in promoter regions, implied their potential roles in stress responsiveness. Differential expression patterns for HanSAMS genes were observed in different tissues as well as under hormone treatment or abiotic stress conditions by analyzing RNA-seq data from previous studies and qRT-PCR data in our current study. The majority of genes demonstrated a robust response to BRA and IAA treatments in leaf tissues, with no significant expression change observed in roots, suggesting the response of HanSAMS genes to hormones is tissue-specific. Expression analyses under abiotic stresses demonstrated diverse expression profiles of HanSAMS genes, with HanSAMS5 showing significant upregulation in response to both drought and salt stresses.DiscussionThis comprehensive genomic and expression analysis provides valuable insights into the SAMS gene family in sunflowers, laying a robust foundation for future functional studies and applications in crop improvement for stress resilience.

Comparative transcriptomic and proteomic analyses of two salt-tolerant alfalfa (Medicago sativa L.) genotypes: investigation of the mechanisms underlying tolerance to salt

Abiotic stressors such as salt stress restrict plant development and output, which lowers agricultural profitability. In this study, alfalfa (Medicago sativa L.) varieties with different levels of salt tolerance were examined using high-throughput RNA sequencing (RNA-Seq) and Tandem Mass Tags (TMT) technologies to study the reactions of the root systems to salt stress, from transcriptomics and proteomics perspectives. The varieties Atlantic (AT) and Zhongmu-1 (ZM-1) were selected and evaluated after 2 h and 6 h of treatment with 150 mM NaCl. The results showed that under salt stress for 2 h, 1810 differentially expressed genes (DEGs) and 160 differentially expressed proteins (DEPs) in AT were screened, while 9341 DEGs and 193 DEPs were screened in ZM-1. Under salt stress for 6 h, 7536 DEGs and 118 DEPs were screened in AT, while 11,754 DEGs and 190 DEPs were screened in ZM-1. Functional annotation and pathway enrichment analyses indicated that the DEGS and DEPs were mainly involved in the glutathione metabolism, biosynthesis of secondary metabolites, glycolysis/gluconeogenesis, carbon fixation in photosynthetic organisms, and photosynthesis pathways. A series of genes related to salt tolerance were also identified, including GSTL3 and GSTU3 of the GST gene family, PER5 and PER10, of the PER gene family, and proteins such as APR and COMT, which are involved in biosynthesis of secondary metabolites. This study provides insights into salt resistance mechanisms in plants, and the related genes and metabolic pathways identified may be helpful for alfalfa breeding in the future.

PP2 gene family in Phyllostachys edulis: identification, characterization, and expression profiles.

Phloem protein 2 (PP2), a dimeric lectin, is known for its involvement in plant responses to biotic and abiotic stresses. However, research on PP2 proteins in Moso bamboo is lacking. In this study, comprehensive genome-wide analysis of the PP2-like gene family was conducted in Moso bamboo (Phyllostachys edulis), which has a significant economic and ecological value. Using HMMER3 search and InterPro domain analysis, 23 PP2-like genes (PhePP2-1 to PhePP2-23) were identified in the P. edulis genome. These genes were distributed across 12 chromosomal scaffolds, with proteins ranging from 216 to 556 amino acids in length. Phylogenetic analysis, including 163 PP2 proteins from eight plant species, revealed six distinct groups, with Group III and Group V being the largest. Gene structure and motif analyses indicated conserved domains across the PhePP2 proteins. In addition, Cis-element analysis of the promoter regions highlighted their potential regulatory roles in hormone, stress, and light responses. Expression pattern analysis using RNA-seq data showed differential expression of PhePP2 genes under drought, salt, salicylic acid, and abscisic acid treatments, indicating their involvement in stress response pathways. Furthermore, qPCR validation in different tissues and organs of Moso bamboo confirmed the expression profiles of the selected PhePP2 genes. This study provides a comprehensive understanding of the functional roles of PP2-like genes in Moso bamboo and insights into their potential applications in enhancing stress tolerance and growth in plants.

Genome-Wide Characterization of Solanum tuberosum CCoAOMT Gene Family and Identification of StCCoAOMT Genes Involved in Anthocyanin Biosynthesis

Background: The caffeoyl-CoA-O methyltransferase (CCoAOMT) family plays essential roles in the methylation of various secondary metabolites, including anthocyanins. Despite the wide identification of the CCoAOMT family in plants, the characterization and function of CCoAOMT protein members in Solanum tuberosum remain poorly understood. Methods and Results: In this study, a total of 12 StCCoAOMT members were identified in the genome of S. tuberosum using the Blastp and HMM search and were unevenly located on eight chromosomes. Collinearity analysis revealed that four tandem duplicated gene pairs and two segmental duplicated gene pairs existed in the S. tuberosum genome, demonstrating that duplication events play a key role in the expansion of the CCoAOMT family. All StCCoAOMTs were clustered into group I and group II based on phylogenetic analysis, which was further verified by the conserved motifs and gene structures analysis. The cis-acting elements analysis illustrated that StCCoAOMTs might be important for photosynthesis, hormone responses, and abiotic stress. Expression analysis demonstrated that StCCoAOMT genes have diverse transcript levels in various tissues and that StCCoAOMT10 was significantly expressed in purple potatoes with abundant anthocyanin content according to RNA-seq data and qRT-PCR assays. In addition, the subcellular localization assay validated that the StCCoAOMT10 protein was mainly localized in the cytoplasm and nucleus. Conclusions: These results will be of great importance for a better understanding of the features of CCoAOMT family members, especially of the candidate genes involved in the methylation of anthocyanins in S. tuberosum, and also for improving the nutritional quality of S. tuberosum.

Abstract IA005: Tumor cell-based liquid biopsy to characterize prostate cancer

Abstract Circulating Tumor Cells (CTCs) hold the promise of comprehensive yet noninvasive molecular characterization of cancer cells during the course of tumor evolution and progression. To dissect the epigenetic profile of prostate CTCs, we undertook paired DNA methylation and RNA sequencing of single CTCs isolated from blood specimens of patients with prostate cancer. Across the genome, our study identified 40 core Partial Methylation Domains (PMDs) that arise early in tumorigenesis and are shared by all individual CTCs across multiple patients. Key among these is a single genomic locus harboring multiple interferon-inducible genes along with all the CD1 gene family members, implicated in innate immunity. Based on mouse models, we propose that early biallelic silencing of multiple genes residing within a single PMD may contribute to the escape from immune surveillance in prostate and potentially other cancers. Studies of CTC heterogeneity within individual patients are limited by the very small number of cells that can be isolated from standard 10ml blood volumes. To enable such analyses, we applied a new high throughput microfluidic platform, capable of processing an entire leukapheresis product, interrogating 2-3 L of blood volume equivalent. Applying this technology to patients with metastatic prostate cancer, we successfully enriched thousands of CTCs from individual cases, enabling the characterization of intra-patient heterogeneity at the level of cell morphology and marker expression, chromosome copy number variation and exome-wide genotyping, and transcriptionally-defined tumor cell subpopulations. Such high-volume microfluidic enrichment of CTCs constitutes a new dimension in liquid biopsies. Citation Format: Daniel A Haber, Shyamala Maheswaran, Hongshan Guo, Joanna Vuille, Shih-Bo Huang, Ben S Wittner, Lecia V Sequist, Richard J Lee, Patricia AR Brunker, David T Miyamoto, Avanish Mishra, Mehmet Toner. Tumor cell-based liquid biopsy to characterize prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr IA005.

Genome-wide identification of the OVATE gene family and revelation of its expression profile and functional role in eight tissues of Rosa roxburghii Tratt.

The OVATE gene family is a new class of transcriptional repressors, which play an important regulatory role in plant growth and development. Many studies have proved that the OVATE gene family can regulate the development of plant tissues and organs and resist stress, but its quantity and functional role in Rosa roxburghii remain unknown. In this study, 14 OVATE family members were identified by re-annotating the genome of Rosa roxburghii, and these members were unevenly distributed on 6 chromosomes. Evolutionary analysis indicated that these family members were classified into three groups. In their promoter regions, many hormone-related cis-acting elements such as ABA, GA, and MeJA were identified. Segmental duplication is an important driving force for the expansion of the OVATE family in Rosa roxburghii. Transcriptome sequencing and RT-qPCR analysis showed that OVATE gene family had a specific tissue expression pattern in Rosa roxburghii. For instance, the expression level of gene Rr602241 in leaves was more than 4 times that of other tissues. The gene Rr101515 was highly expressed in FR1 and FR4 stages of fruit tree development, and was highly homologous to the gene regulating fruit shape in tomatoes. These results suggest that members of the OVATE gene family may have diverse functions in different tissues. Furthermore, based on the transcriptome data of eight tissues, a transcriptional regulatory co-expression network of different transcription factors and 14 OVATE genes was constructed. In conclusion, our study provides the expression profiles of the OVATE family and reveals the potential functional roles of different members in the growth and development of Rosa roxburghii Tratt.

Comparative genomics of obligate predatory bacteria belonging to phylum Bdellovibrionota highlights distribution and predicted functions of lineage-specific protein families.

Comparative genomics of predatory bacteria is important to understand their ecology and evolution and explore their potential to treat drug-resistant infections. We compared chromosomes of 18 obligate predators from phylum Bdellovibrionota (16 intraperiplasmic, two epibiotic) and 15 non-predatory bacteria. Phylogenetics of conserved single-copy genes and analysis of genome-wide average amino acid identity provide evidence for at least five Bdellovibrio species and support recent reclassifications of predatory taxa. To define shared and differential genome content, we grouped predicted protein sequences into gene clusters based on sequence similarity. Few gene clusters are shared by all 33 bacteria or all 18 predatory bacteria; however, we identified gene clusters conserved within lineages, such as intraperiplasmic Bdellovibrio, and not found in other bacteria. Many of these are predicted to function in cell envelope biogenesis, signal transduction, and other roles important for predatory lifestyles. Among intraperiplasmic Bdellovibrio, we detected high abundance of gene clusters predicted to encode transglycosylases, endopeptidases, and lysozymes, and we identified six gene clusters (amidase, L,D-transpeptidase, four transglycosylases) with evidence of recent gene duplication and gene family expansion. Focusing on peptidoglycan metabolism, we defined a suite of gene clusters that include peptidoglycan-degrading and -modifying enzymes and occur only in predatory bacteria, suggesting these proteins may have evolved activities specific to predation. Our analyses highlight key genome content differences between obligate predatory bacteria and non-predatory relatives and identify gene clusters that may encode enzymes adapted to predatory lifestyles. These lineage-specific proteins are strong candidates for functional characterization to clarify their role in predation.IMPORTANCEEvolution of predation as a bacterial lifestyle involves selective pressure on and adaptation of enzymes that contribute to killing and digestion of prey bacteria, in some cases from within the prey itself. Such enzymes are a hallmark of obligate predatory bacteria belonging to phylum Bdellovibrionota, which includes the well-studied predator Bdellovibrio. By comparing protein sequences of obligate predatory bacteria and their non-predatory relatives, we define key genome content differences that distinguish bacterial predators and identify lineage-specific enzymes that may have evolved unique activities due to selective pressures related to a predatory lifestyle. In addition to providing insights into the ecology and evolution of predatory bacteria, comparative genomics studies, like this, can inform efforts to develop predatory bacteria and/or their enzymes as potential biocontrol agents to combat drug-resistant bacterial infections.

KAT6B is required for histone 3 lysine 9 acetylation and SOX gene expression in the developing brain.

Heterozygous mutations in the histone lysine acetyltransferase gene KAT6B (MYST4/MORF/QKF) underlie neurodevelopmental disorders, but the mechanistic roles of KAT6B remain poorly understood. Here, we show that loss of KAT6B in embryonic neural stem and progenitor cells (NSPCs) impaired cell proliferation, neuronal differentiation, and neurite outgrowth. Mechanistically, loss of KAT6B resulted in reduced acetylation at histone H3 lysine 9 and reduced expression of key nervous system development genes in NSPCs and the developing cortex, including the SOX gene family, in particular Sox2, which is a key driver of neural progenitor proliferation, multipotency and brain development. In the fetal cortex, KAT6B occupied the Sox2 locus. Loss of KAT6B caused a reduction in Sox2 promoter activity in NSPCs. Sox2 overexpression partially rescued the proliferative defect of Kat6b -/- NSPCs. Collectively, these results elucidate molecular requirements for KAT6B in brain development and identify key KAT6B targets in neural precursor cells and the developing brain.

Genome-wide analysis of the PLATZ gene family provides insights into the genome evolution of cultivated peanut (Arachis hypogaea, Leguminosae)

Genome-wide analysis of the PLATZ gene family provides insights into the genome evolution of cultivated peanut (Arachis hypogaea, Leguminosae)

Multi-trait association analysis reveals shared genetic loci between Alzheimer's disease and cardiovascular traits.

Several cardiovascular traits and diseases co-occur with Alzheimer's disease. We mapped their shared genetic architecture using multi-trait genome-wide association studies. Subsequent fine-mapping and colocalisation highlighted 16 genetic loci associated with both Alzheimer's and cardiovascular diseases. We prioritised rs11786896, which colocalised with Alzheimer's disease, atrial fibrillation and expression of PLEC in the heart left ventricle, and rs7529220, which colocalised with Alzheimer's disease, atrial fibrillation and expression of C1Q family genes. Single-cell RNA-sequencing data, co-expression network and protein-protein interaction analyses provided evidence for different mechanisms of PLEC, which is upregulated in left ventricular endothelium and cardiomyocytes with heart failure and in brain astrocytes with Alzheimer's disease. Similar common mechanisms are implicated for C1Q in heart macrophages with heart failure and in brain microglia with Alzheimer's disease. These findings highlight inflammatory and pleomorphic risk determinants for the co-occurrence of Alzheimer's and cardiovascular diseases and suggest PLEC, C1Q and their interacting proteins as potential therapeutic targets.