Lamiales is an order of core eudicots with abundant diversity, and many Lamiales plants have important medicinal and ornamental values. Here, we comparatively reanalyzed 11 Lamiales species with well-assembled genome sequences and found evidence that Lamiales plants, in addition to a hexaploidization or whole-genome triplication (WGT) shared by core eudicots, experienced further polyploidization events, establishing new groups in the order. Notably, we identified a whole-genome duplication (WGD) occurred just before the split of Scrophulariaceae from the other Lamiales families, such as Acanthaceae, Bignoniaceae, and Lamiaceae, suggesting its likely being the causal reason for the establishment and fast divergence of these families. We also found that a WGT occurred ∼68-78 Mya, near the split of Oleaceae from the other Lamiales families, implying that it may have caused their fast divergence and the establishment of the Oleaceae family. Then, by exploring and distinguishing intra- and inter-genomic chromosomal homology due to recursive polyploidization and speciation, respectively, we inferred that the Lamiales ancestral cell karyotype had 11 proto-chromosomes. We reconstructed the evolutionary trajectories from these proto-chromosomes to form the extant chromosomes in each Lamiales plant under study. We must note that most of the inferred 11 proto-chromosomes, duplicated during a WGD thereafter, have been well preserved in Jacaranda (Jacaranda mimosifolia) genome, showing the credibility of the present inference implementing a telomere-centric chromosome repatterning model. These efforts are important to understand genome repatterning after recursive polyploidization, especially shedding light on the origin of new plant groups and angiosperm cell karyotype evolution.
Objectives: Disruption of gut–liver axis homeostasis is a hallmark of metabolic and toxic stress. This study aimed to evaluate the combined effects of high-fat diet (HFD), aflatoxin B1 (AFB1), and exogenous isoleucine supplementation on immunometabolic function under nutritional and toxic stress. Methods: Two-phase murine experiments assessed: (1) HFD and AFB1 effects individually and combined; and (2) dose-dependent isoleucine responses (25/50/100 mg/kg) across control, HFD, and HFD + AFB1 backgrounds. Results: HFD significantly impaired liver function, promoted Th17-mediated inflammation, and induced gut dysbiosis, while AFB1 alone exerted minimal effects. Their combination synergistically exacerbated hepatic steatosis, intestinal barrier disruption, and inflammatory responses. Fecal metabolomics identified elevated isoleucine as a potential inflammatory biomarker. Under HFD, isoleucine (50 mg/kg) amplified inflammation and oxidative stress. Remarkably, under HFD + AFB1, moderate/high-dose isoleucine reduced hepatic lipid deposition and triglycerides despite persistent intestinal damage, demonstrating context-dependent effects. Conclusions: HFD and AFB1 synergistically disrupt gut–liver axis integrity through immunometabolic mechanisms. Isoleucine supplementation exhibits dual-modulatory effects, exacerbating damage under nutritional stress while partially mitigating hepatic lipid accumulation under combined toxic-nutritional stress, highlighting the critical importance of environmental context in amino acid interventions.
Rice (Oryza sativa) is one of the key staple crops, providing food for nearly half of the world’s population. The past twenty years have seen significant advances in understanding Oryza species through genome sequencing efforts. However, the stability of Oryza genomes during their divergence has not been well characterized. Here, by performing gene collinearity and comparative genomics analysis, we selected ten Oryza species and three other Poaceae species to check their genome stability, with Leersia perrieri as the reference. Intra- and intergenomic analysis showed a ~30% difference in homologous block numbers and a 35.7% difference in collinear gene numbers per block, indicating that Oryza genomes have undergone extensive DNA permutations. Notably, we found that Oryza chromosomes with smaller ordinal numbers have often preserved larger percentages of genes, while those with bigger numbers have undergone more gene losses. This unique observation may be explained by elevated gene losses incurred by illegitimate or homoeologous recombination between homoeologous chromosomes produced by the grass-common tetraploidization (GCT) ~100 million years ago (Mya), e.g., Chro. 11 and 12. However, the lowered gene loss rates in Chro. 1–3 could be explained by earlier restriction of illegitimate recombination after the GCT due to there often being (larger) neo-chromosomes produced by the fusion of ancestral chromosomes. The enriched NBS-LRR (nucleotide-binding site and leucine-rich repeat) genes in chromosomes 11 and 12 are another explanation for the above observation. Further evidence was obtained from other Poaceae plants. Moreover, we revealed around twice as many differences in tandem genes and their densities among Oryza plants, further showing their divergent levels of genome stability. The present efforts may contribute to the understanding of the stability of the Oryza genome and its formation, evolution, and functional innovation.
Gene conversion contributes to gene copy number changes, DNA mutations, and functional innovation and has been widely reported in three domains of life. However, it has hardly been described in Aspergillus, including industrially and commercially important or pathogenic fungi. Here, we revealed multiple sets of homologous genes located in a region of chromosome 1 of A. flavus, and its orthologous counterpart of A. oryzae. Phylogenetic analysis showed evidence of frequent gene (DNA) conversion between ectopic paralogs in each species, accompanied by prominent point mutations and DNA deletion (from several to hundreds of base pairs). At least two independent cases showed that the converted genes in A. oryzae have been repeatedly split into shorter genes by the introduction of stop codons, and then ectopic conversion rendered paralogous genes (regions) to have the same configuration of tandemly located new genes. Inference of nucleotide substitution and ancestral gene content showed that the conversion-affected regions have seen 3.48 times as many substitutions and 4–6 times as many gene losses compared to the non-affected regions. We predicted that a DNA loop between proximal regions, in the common ancestor and inherited by each species, facilitates ectopic gene (DNA) conversion and elevated rates of mutations and losses. Overall, we found that gene conversion proves to be a key factor resulting in genome instability, elevated gene evolutionary rates, and an effective avenue to produce new genes, likely leading to the speciation of two Aspergillus lineages.