Biology-Basel最新文献

The MATα_HMGbox and HMG-box_ROX1-like domains of the MAT1-1-1 and MAT1-2-1 proteins, respectively, play essential roles in DNA binding and the subsequent regulation of gene transcription, controlling Ophiocordyceps sinensis sexual reproduction. Alternative splicing, differential occurrence and transcription of the MAT1-1-1 and MAT1-2-1 genes have been demonstrated in Hirsutella sinensis (GC-biased Genotype #1 of the 17 O. sinensis genotypes), suggesting self-sterility under heterothallic or hybrid outcrossing. In this study, the MATα_HMGbox domains of MAT1-1-1 proteins in wild-type Cordyceps sinensis isolates were shown to cluster into 5 clades in the Bayesian clustering tree and belong to diverse stereostructure morphs under 19 AlphaFold codes. The HMG-box_ROX1-like domains of MAT1-2-1 proteins, on the other hand, were shown to cluster into 2 branched Bayesian clades and belong to stereostructure morphs under 25 AlphaFold codes. Correlation analysis revealed that 1-3 amino acid substitutions in the DNA-binding domains of the mating proteins resulted in altered hydrophobicity and secondary and tertiary structures of the DNA-binding domains of the proteins, especially altered stereostructures of the hydrophobic cores formed by 3 critical α- helices within the functional domains of the proteins. Fungal origin analysis revealed possible heterospecific fungal sources of mating proteins with stereostructure variations in wild-type C. sinensis isolates, suggesting that alterations in DNA binding function and the subsequent regulation of mating-related gene transcription are involved in ensuring the accuracy and genetic diversity of heterothallic and hybrid reproduction of O. sinensis during the lifecycle of the C. sinensis insect-fungal complex.

Whole-genome duplication, or tetraploidization, occurs in cells, tissues, or entire organisms. In human cancers, tetraploidization promotes aneuploidy and genomic instability, accelerating tumor progression, metastasis, and drug resistance. These adaptations demand metabolic rewiring, including mitochondrial plasticity. Here, we investigate the relationship between mitochondrial quantity/activity, including the mitochondrial transmembrane potential, the intracellular calcium, and the oxidative stress in diploid versus tetraploid cancer cells (colon, sarcoma, liver) and fungal and yeast models (C. albicans diploid/tetraploid strains; S. cerevisiae haploid/diploid/tetraploid strains). We demonstrate that tetraploid cells, whether from human carcinomas or yeast, exhibit consistently enlarged cell size, elevated mitochondrial content, and heightened metabolic activity compared to diploids. Our findings underscore mitochondrial adaptation as a hallmark of tetraploidization, offering novel therapeutic targets for chromosomally unstable tumors.

Sphaerodactylidae play a crucial role in ecosystems, possessing significant ecological, scientific, and conservation value. They contribute to pest control and the maintenance of ecological balance, and also provide abundant materials for research in evolutionary biology and biodiversity. To refine the phylogenetic position of Teratoscincus scincus within the Sphaerodactylidae using mitogenomic data, this study sequenced the complete mitochondrial genome of T. scincus using the Illumina NovaSeq Xplus platform, and subsequently performed assembly, annotation, and analysis. The phylogenetic relationships of T. scincus within the Sphaerodactylidae were analyzed using 13 protein-coding genes (PCGs) from the mitochondrial genome via Bayesian inference (BI) and maximum likelihood (ML) methods. The complete mitochondrial genome of T. scincus is 16,943 bp in length and consists of 13 PCGs, 22 tRNA genes, 2 rRNA genes, and 1 control region (D-loop). The base composition shows a distinct AT preference, with the highest A + T content (56.3%) found in the PCGs region. A phylogenetic tree was constructed based on the amino acid sequences of 13 PCGs from the mitochondrial genomes of nine Sphaerodactylidae species retrieved from GenBank and the newly sequenced T. scincus generated in this study. The results confirm that T. scincus belongs to the genus Teratoscincus within the family Sphaerodactylidae. Phylogenetic analysis reveals that T. scincus and Teratoscincus keyserlingii cluster into a monophyletic group, suggesting a close phylogenetic relationship. Additionally, the phylogenetic tree provides new molecular evidence for understanding the formation mechanism of Sphaerodactylidae diversity. This study not only enriches the mitochondrial genome database of Sphaerodactylidae but also lays an important foundation for subsequent research on the adaptive evolution and conservation biology of T. scincus.

Copepods are key components of marine food webs, linking primary producers such as microalgae to higher trophic levels, including many fish species. This study investigates long-term changes in the composition, density, and biomass of copepod communities along the Romanian coast of the Black Sea over six decades (1956-2015), based on historical records and recent monitoring from 18 sampling stations. Mean copepod density declined markedly over the study period, particularly during the cold season, decreasing from values exceeding 1000 ind/m³ in the 1960s to <300 ind/m³ after 2000, while biomass showed weaker but comparable long-term fluctuations. Seasonal variability was pronounced, with significantly higher densities and biomass during the warm season. Generalised Additive Models (GAMs) explained up to 40-55% of the variance in copepod density and biomass, depending on the season. During the warm season, phosphate exerted a positive effect on copepod abundance, consistent with bottom-up control via phytoplankton productivity, whereas during the cold season, temperature showed a positive effect and salinity a negative effect, indicating stronger physical control of copepod persistence. Species composition shifted over time, with a reduction in constant species and an increase in rare or accidental taxa in later decades. These results indicate that climate variability and anthropogenic pressures have reshaped copepod communities, with potential consequences for food-web efficiency and ecosystem resilience in the Black Sea.

Tail fat deposition constitutes a distinctive adaptive phenotype in sheep. The Large-tailed Han (LTH) and Small-tailed Han (STH) breeds display pronounced divergence in tail fat storage, offering an ideal model for elucidating lipid metabolism regulation. Integrated sRNA-Seq and RNA-Seq analysis identified 521 differentially expressed genes and 144 miRNAs, which were significantly enriched in lipid metabolism pathways, including fatty acid metabolism and PPAR signaling. Key candidate genes (ADIRF, LPL, ACSL5) were highlighted as pivotal regulators. Additionally, 23 miRNA-mRNA regulatory networks were constructed, revealing complex interaction patterns from 'one-to-one' to 'many-to-one' relationships. For example, six miRNAs collectively targeted LTA4H. Collectively, this study advances understanding of the genetic network underlying tail fat deposition and provides candidate targets for modulating lipid metabolism. Functional validation is warranted to delineate causal mechanisms.

Orthodontic force magnitude influences angiogenesis during orthodontic tooth movement (OTM); however, the role of senescent cells remains largely unclear. This study investigated the localization of senescent cells and their expression of vascular endothelial growth factor (VEGF) during angiogenesis using a rat horizontal OTM model with different force magnitudes. Nickel-titanium coil springs exerting 60 g or 180 g of orthodontic force were applied to the maxillary first molar of 15-week-old male Sprague-Dawley rats; untreated rats served as controls. Tooth movement was evaluated by stereomicroscopy and micro-computed tomography. Senescent cells (p21, p16) and angiogenesis (CD31 and VEGF) were evaluated by multiplex immunofluorescence. Tooth movement was observed under both the 60 g and 180 g conditions. The 60 g group showed increased cellularity, vascular density, and VEGF expression, suggesting an optimal mechanical force. In contrast, the 180 g group reduced cellularity and angiogenesis, consistent with excessive force. Senescent cells were more abundant in the 60 g group, with over 40% expressing VEGF. These findings suggest that force magnitude influences the presence of VEGF⁺ senescent cells, which may be associated with the angiogenic process in OTM. This work provides insights into the mechanisms underlying optimal force in orthodontic treatment.

Between 2022 and 2024, a severe branch dieback disease was observed affecting over 6% of sweet cherry trees of the 'Tieton' cultivar in commercial greenhouses in southern Liaoning Province, China. Symptoms primarily occurred at the top of young branches. At the early stage of disease onset, the lesions appeared as dark brown, irregularly shaped areas with a moist surface; as the disease progressed, these lesions turned dry and rotten, leading to tree decline symptoms in sweet cherry trees. Disease diagnosis was carried out in sweet cherry greenhouses across Liaoning Province, where 24 diseased samples were collected and 14 fungal isolates were obtained therefrom. Based on morphological traits, cultural characteristics, and multi-locus phylogenetic analyses of the internal transcribed spacer (ITS) region, beta-tubulin (TUB2) gene, and translation elongation factor 1-α (TEF1) gene, these isolates were identified as Botryosphaeria dothidea. Two representative isolates, namely zdcy-1 and zdcy-2, were selected for pathogenicity assays. Both mycelial plug and spore suspension inoculation methods confirmed the pathogenicity of the pathogen. The biological characteristic assays revealed that the optimal temperature range for the pathogen's mycelial growth on PDA medium was 25-28 °C, and the optimal pH range was 6.0-8.0. This study improves the understanding of branch dieback disease in sweet cherry orchards in China, enriches the knowledge regarding the geographical distribution, host range, and infection sites of the pathogen, and provides novel insights for the management of sweet cherry diseases.

Potato (Solanum tuberosum L.) is one of the most widely cultivated crops in the world; however, drought is a major constraint to its productivity. Arbuscular mycorrhizal fungi (AMF) have been shown to improve plant resistance under conditions of water stress. However, their effects on potato plants are poorly studied. The purpose of this study was to evaluate the potential of two AMF inocula (two different strains of the AMF species Rhizophagus irregularis with different origin: Southern Spain MI₁ and Tunisia MI₂) on potato tolerance to drought stress through the determination of growth parameters, photosynthetic parameters, and antioxidant systems, under well-watered (WW; field capacity) and drought stress (DS; 50% of field capacity) conditions. Therefore, the experiment consisted of two factors: AMF strain and watering regime. The results showed that under drought stress conditions, AMF inoculation considerably stimulated photosynthetic performance as compared with non-inoculated controls. Moreover, leaf superoxide dismutase (SOD) and catalase (CAT) activities of inoculated plants were higher in WW conditions, but unchanged in DS conditions. Inoculated plants had significantly higher ascorbate peroxidase (APX) and glutathione reductase (GR) activities than non-inoculated plants under DS conditions. Also, expression of some antioxidant enzyme genes were upregulated by inoculation. Lipid peroxidation content of inoculated plants was lower than that of non-inoculated. Furthermore, there was a high positive correlation between mycorrhizal root colonization (RC) and almost all the measured parameters. The results of this study indicated that AMF inoculation could enhance potato plant tolerance to water stress through the induction of antioxidant mechanisms implicated in scavenging oxygen-free radicals.

Plant organic cation transporters (OCTs) are involved in a variety of beneficial biological processes, such as cadaverine transfer in plants and soil, and play an active role in the formation of plant stress resistance. In this study, 52 OCT family genes were identified in tomato, and comprehensive bioinformatics analyses of these numbers, such as promoter cis-acting elements, gene mapping and collinearity, protein characterization and phylogenetic analysis. By analyzing the expression of tomato OCT family genes under cold and salt stresses using transcriptome data and qRT-PCR experiments, a key gene regulating cold stress tolerance, SlOCT20, was identified. Subcellular localization experiments indicated that SlOCT20 was mainly localized in the cell membrane. When the SlOCT20 gene was silenced in tomato, the tolerance to cold stress was significantly reduced and oxidative stress was aggravated, indicating that this gene positively regulates the tolerance to cold stress in tomato.

Mactra antiquata sensu lato, a commercially important clam species in China, exhibits remarkable morphological and molecular diversity, which has led to the proposal of cryptic species within this complex. In the present study, specimens of M. antiquata sensu lato were collected from four coastal provinces (Shandong, Guangdong, Guangxi, and Hainan) of China, and an integrated comparative analysis was performed based on morphological traits and partial sequences of two mitochondrial genes (cytochrome c oxidase subunit I, COI; and 16S rRNA). Our results revealed that M. antiquata sensu lato could be clearly delineated into two distinct clades: the N-group (comprising specimens collected from Shandong in this study) and the S-group (including specimens collected from Guangdong, Guangxi, and Hainan), with significant intergroup differences. Morphologically, S-group individuals possessed relatively narrower shells (mean shell width-to-length ratio = 0.465) and shorter shells (mean shell height-to-length ratio = 0.781) compared to N-group conspecifics. Additionally, the pallial sinus of S-group clams extended directly toward the anterior adductor muscle, whereas that of N-group clams pointed to the region below the anterior adductor muscle. Furthermore, the escutcheon of N-group individuals was considerably more slender than that of the S-group. Phylogenetic trees and haplotype networks constructed based on both partial COI and 16S rRNA sequences further confirmed a deep genetic divergence between the two groups, with Kimura 2-parameter distances of 0.158 for COI and 0.084 for 16S rRNA. Collectively, these morphological and molecular lines of evidence strongly support the existence of cryptic species within M. antiquata sensu lato. By comparing the morphological characteristics of specimens in this study with the original description of M. antiquata, we herein propose that the S-group represents a new species, which we named M. haiboensis sp. nov. Our findings provide a scientific basis for the targeted conservation and further research of both M. antiquata and M. haiboensis sp. nov.