Marine Life Science & Technology最新文献

Mangroves are adapted to intertidal zones, which present extreme environmental conditions. WRKYs are among the most prominent transcription factors (TFs) in higher plants and act through various interconnected networks to regulate responses to multiple abiotic stressors. Here, based on omic data, we investigated the landscape and evolutionary patterns of WRKYs in the main mangrove genus Avicennia. We found that both the number and the proportion of TFs and WRKYs in Avicennia species exceeded their inland relatives, indicating a significant expansion of WRKYs in Avicennia. We identified 109 WRKY genes in the representative species Avicennia marina. Comparative genomic analysis showed that two recent whole-genome duplication (WGD) events played a critical role in the expansion of WRKYs, and 88% of Avicennia marina WRKYs (AmWRKYs) have been retained following these WGDs. Applying comparative transcriptomics on roots under experimental salt gradients, we inferred that there is high divergence in the expression of WGD-retained AmWRKYs. Moreover, we found that the expression of 16 AmWRKYs was stable between freshwater and moderately saline water but increased when the trees were exposed to high salinity. In particular, 14 duplicates were retained following the two recent WGD events, indicating potential neo- and sub-functionalization. We also found that WRKYs could interact with other upregulated genes involved in signalling pathways and natural antioxidant biosynthesis to enhance salt tolerance, contributing to the adaptation to intertidal zones. Our omic data of the WRKY family in A. marina broadens the understanding of how a TF family relates to the adaptive evolution of mangroves.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00177-y.

Chitosan oligosaccharides (COSs) have been reported to possess a broad range of activities such as antitumor, antioxidant and neuroprotective activities. In this study, the protective effects and mechanisms of peracetylated chitosan oligosaccharides (PACOs) against Aβ-induced cognitive deficits were investigated in Sprague-Dawley (SD) rats. PACOs treatment significantly improved the learning and memory function of Alzheimer's disease (AD) rats and attenuated the neuron cell damage caused by Aβ. PACOs also markedly reduced the levels of lactate dehydrogenase (LDH) and Malondialdehyde (MDA) and decreased the phosphorylation of Tau protein to inhibit oxidative injury and inflammatory responses in AD rats. Further studies indicated that PACOs may promote the repair of Aβ induced nerve damage and inhibit neuronal apoptosis mainly through regulating PI3K/Akt/GSK3β signaling pathway. Consistently, the transcriptome analysis verified that the differentially expressed genes (DEGs) were mainly involved in neuron development and the PI3K-Akt signaling pathway. Taken together, peracetylated chitosan oligosaccharides (PACOs) have the potential to be developed into novel anti-AD agents targeting the cellular PI3K/Akt/GSK3β signaling pathway.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00172-3.

Exploring how food web complexity emerges and evolves in island ecosystems remains a major challenge in ecology. Food webs assembled from multiple islands are commonly recognized as highly complex trophic networks that are dynamic in both space and time. In the context of global climate change, it remains unclear whether food web complexity will decrease in a monotonic fashion when undergoing habitat destruction (e.g., the inundation of islands due to sea-level rise). Here, we develop a simple yet comprehensive patch-dynamic framework for complex food web metacommunities subject to the competition-colonization tradeoff between basal species. We found that oscillations in food web topological complexity (characterized by species diversity, mean food chain length and the degree of omnivory) emerge along the habitat destruction gradient. This outcome is robust to changing parameters or relaxing the assumption of a strict competitive hierarchy. Having oscillations in food web complexity indicates that small habitat changes could have disproportionate negative effects on species diversity, thus the success of conservation actions should be evaluated not only on changes in biodiversity, but also on system robustness to habitat alteration. Overall, this study provides a parsimonious mechanistic explanation for the emergence of food web complexity in island ecosystems, further enriching our understanding of metacommunity assembly.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00167-0.

Non-alcoholic steatohepatitis (NASH) is a primary cause of cirrhosis and hepatocellular carcinoma. Unfortunately, there is no approved drug treatment for NASH. AMP-activated kinase (AMPK) is an important metabolic sensor and whole-body regulator. It has been proposed that AMPK activators could be used for treating metabolic diseases such as obesity, type 2 diabetes and NASH. In this study, we screened a marine natural compound library by monitoring AMPK activity and found a potent AMPK activator, candidusin A (CHNQD-0803). Further studies showed that CHNQD-0803 directly binds recombinant AMPK with a K_D value of 4.728 × 10^-8 M and activates AMPK at both molecular and intracellular levels. We then investigated the roles and mechanisms of CHNQD-0803 in PA-induced fat deposition, LPS-stimulated inflammation, TGF-β-induced fibrosis cell models and the MCD-induced mouse model of NASH. The results showed that CHNQD-0803 inhibited the expression of adipogenesis genes and reduced fat deposition, negatively regulated the NF-κB-TNFα inflammatory axis to suppress inflammation, and ameliorated liver injury and fibrosis. These data indicate that CHNQD-0803 as an AMPK activator is a novel potential therapeutic candidate for NASH treatment.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00168-z.

The majority of marine ammonia oxidizers belong to Thaumarchaeota, a phylum of Archaea, which is distributed throughout the water column. Marine surface waters contain distinct thaumarchaeotal phylotypes compared to the deeper ocean, but spatial dynamics of the surface-associated lineages are largely unsolved. This study of 120 seawater samples from the eastern Chinese marginal seas identified contrasting distribution and association patterns among thaumarchaeotal phylotypes across different dimensions. Horizontally, Nitrosopumilus-like and Nitrosopelagicus-like phylotypes dominated the surface water (3 m) of the Yellow Sea (YS) and East China Sea (ECS), respectively, along with increased abundance of total free-living Thaumarchaeota in ECS. Similar compositional changes were observed in the surface microlayer. The spatial heterogeneity of particle-attached Thaumarchaeota was less clear in surface microlayers than in surface waters. Vertically, the Nitrosopelagicus-like phylotype increased in abundance from surface to 90 m in ECS, which led to an increase in the proportion of Thaumarchaeota relative to total prokaryotes. This occurred mainly in the free-living fraction. These results indicate a clear size-fractionated niche partitioning, which is more pronounced at lower depths than in the surface water/surface microlayer. In addition, associations of Thaumarchaeota with other microbial taxa varied between phylotypes and size fractions. Our results show that a phylotype-resolved and size-fractionated spatial heterogeneity of the thaumarchaeotal community is present in surface oceanic waters and a vertical variation of the Nitrosopelagicus-like phylotype is present in shallow shelf waters.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00169-y.

The large yellow croaker (Larimichthys crocea) is one of the most economically valuable marine fish in China and is a notable species in ecological studies owing to a serious collapse of wild germplasm in the past few decades. The stock division and species distribution, which have important implications for ecological protection, germplasm recovery, and fishery resource management, have been debated since the 1960s. However, it is still uncertain even how many stocks exist in this species. To address this, we evaluated the fine-scale genetic structure of large yellow croaker populations distributed along the eastern and southern Chinese coastline based on 7.64 million SNP markers. Compared with the widely accepted stock boundaries proposed in the 1960s, our results revealed that a climate-driven habitat change probably occurred between the Naozhou (Nanhai) Stock and the Ming-Yuedong (Mindong) Stock. The boundary between these two stocks might have shifted northwards from the Pearl River Estuary to the northern area of the Taiwan Strait, accompanied by highly asymmetric introgression. In addition, we found divergent landscapes of natural selection between the stocks inhabiting northern and southern areas. The northern population exhibited highly agminated signatures of strong natural selection in genes related to developmental processes, whereas moderate and interspersed selective signatures were detected in many immune-related genes in the southern populations. These findings establish the stock status and genome-wide evolutionary landscapes of large yellow croaker, providing a basis for conservation, fisheries management and further evolutionary biology studies.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00165-2.

[This corrects the article DOI: 10.1007/s42995-022-00160-z.].

Metabolites of microorganisms have long been considered as potential sources for drug discovery. In this study, five new depsidone derivatives, talaronins A-E (1-5) and three new xanthone derivatives, talaronins F-H (6-8), together with 16 known compounds (9-24), were isolated from the ethyl acetate extract of the mangrove-derived fungus Talaromyces species WHUF0362. The structures were elucidated by analysis of spectroscopic data and chemical methods including alkaline hydrolysis and Mosher's method. Compounds 1 and 2 each attached a dimethyl acetal group at the aromatic ring. A putative biogenetic relationship of the isolated metabolites was presented and suggested that the depsidones and the xanthones probably had the same biosynthetic precursors such as chrysophanol or rheochrysidin. The antimicrobial activity assay indicated that compounds 5, 9, 10, and 14 showed potent activity against Helicobacter pylori with minimum inhibitory concentration (MIC) values in the range of 2.42-36.04 μmol/L. While secalonic acid D (19) demonstrated significant antimicrobial activity against four strains of H. pylori with MIC values in the range of 0.20 to 1.57 μmol/L. Furthermore, secalonic acid D (19) exhibited cytotoxicity against cancer cell lines Bel-7402 and HCT-116 with IC₅₀ values of 0.15 and 0.19 μmol/L, respectively. The structure-activity relationship of depsidone derivatives revealed that the presence of the lactone ring and the hydroxyl at C-10 was crucial to the antimicrobial activity against H. pylori. The depsidone derivatives are promising leads to inhibit H. pylori and provide an avenue for further development of novel antibiotics.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00170-5.

The Permian Basin is a unique ecosystem located in the southwest of the USA. An unanswered question is whether the bacteria in the Permian Basin adapted to the changing paleomarine environment and survived in the remnants of Permian groundwater. In our previous study, a novel bacterial strain, Permianibacter aggregans HW001^T, was isolated from microalgae cultures incubated with Permian Basin waters, and was shown to originate from the Permian Ocean. In this study, strain HW001^T was shown to be the representative strain of a novel family, classified as 'Permianibacteraceae'. The results of molecular dating suggested that the strain HW001^T diverged ~ 447 million years ago (mya), which is the early Permian period (~ 250 mya). Genome analysis was used to access its potential energy utilization and biosynthesis capacity. A large number of transporters, carbohydrate-active enzymes and protein-degradation related genes have been annotated in the genome of strain HW001^T. In addition, a series of important metabolic pathways, such as peptidoglycan biosynthesis, osmotic stress response system and multifunctional quorum sensing were annotated, which may confer the ability to adapt to various unfavorable environmental conditions. Finally, the evolutionary history of strain HW001^T was reconstructed and the horizontal transfer of genes was predicted, indicating that the adaptation of P. aggregans to a changing marine environment depends on the evolution of their metabolic capabilities, especially in signal transmission. In conclusion, the results of this study provide genomic information for revealing the adaptive mechanism of strain HW001^T to the changing ancient oceans.

Supplementary information: The online version contains supplementary material available at 10.1007/s42995-023-00164-3.

Sex determination (SD) involves mechanisms that determine whether an individual will develop into a male, female, or in rare cases, hermaphrodite. Crustaceans harbor extremely diverse SD systems, including hermaphroditism, environmental sex determination (ESD), genetic sex determination (GSD), and cytoplasmic sex determination (e.g., Wolbachia controlled SD systems). Such diversity lays the groundwork for researching the evolution of SD in crustaceans, i.e., transitions among different SD systems. However, most previous research has focused on understanding the mechanism of SD within a single lineage or species, overlooking the transition across different SD systems. To help bridge this gap, we summarize the understanding of SD in various clades of crustaceans, and discuss how different SD systems might evolve from one another. Furthermore, we review the genetic basis for transitions between different SD systems (i.e., Dmrt genes) and propose the microcrustacean Daphnia (clade Branchiopoda) as a model to study the transition from ESD to GSD.