Marine biofouling causes severe economical and environmental challenges to marine industries and maritime activities. Biofouling prevention has emerged as one of the most pressing issues in water-related industries. Recently, the slippery liquid-infused porous surfaces (SLIPSs) have shown great potential for biofouling prevention across a broad spectrum of fouling organisms. However, our understanding of the mechanisms by which SLIPSs prevent biofouling remains limited. In this study, we discovered that oil-infused polydimethylsiloxane elastomer (i-PDMS), a silicone-based SLIPS variant, significantly inhibited the sensory responses of the fouling mussel Mytilopsis sallei , particularly at its sensory organ, the foot. Using bioinformatics and molecular biology analyses, we demonstrated that i-PDMS disrupts larval settlement of M. sallei by interfering with the mechanosensitive transient receptor potential melastatin-subfamily member 7 (TRPM7) channel, which is highly expressed in the foot during the settlement process. Furthermore, adhesion assays and molecular dynamics simulations revealed that the secreted foot proteins of the mussel are unable to effectively interact with the i-PDMS surface due to nanoscale fluctuations at the material interface. These findings enhance our understanding of how fouling organisms sense and adhere to surfaces and provide deeper insights into the antifouling mechanisms of SLIPS.

Most fouling organisms have planktonic larval and benthic adult stages. Larval settlement, the planktonic–benthic transition, is the critical point when biofouling begins. However, our understanding of the molecular mechanisms of larval settlement is limited. In our previous studies, we identified that the AMP-activated protein kinase-silk gland factor 1 (AMPK-SGF1) pathway was involved in triggering the larval settlement in the fouling mussel M. sallei. In this study, to further confirm the pivotal role of SGF1, multiple targeted binding compounds of SGF1 were obtained using high-throughput virtual screening. It was found that the targeted binding compounds, such as NAD⁺ and atorvastatin, could significantly induce and inhibit the larval settlement, respectively. Furthermore, the qRT-PCR showed that the expression of the foot proteins’ genes was significantly increased after the exposure to 10 μM NAD⁺, while the gene expression was significantly suppressed after the exposure to 10 μM atorvastatin. Additionally, the production of the byssus threads of the adults was significantly increased after the exposure to 10–20 μM of NAD⁺, while the production of the byssus threads was significantly decreased after the exposure to 10–50 μM of atorvastatin. This work will deepen our understanding of SGF1 in triggering the larval settlement in mussels and will provide insights into the potential targets for developing novel antifouling agents.

Most benthic marine invertebrates exhibit a characteristic biphasic life cycle, consisting of a planktonic larval stage followed by a benthic adult stage

(1) Background: Animal growth is a complex process, involving the coordination of a wide variety of genes, non-coding RNAs, and pathways. Circular RNAs (circRNAs) belong to a novel class of functional non-coding RNAs (ncRNAs). They have a distinctive ring structure and are involved in various biological processes, including the proliferation, differentiation, and apoptosis of muscle cells. The Pacific abalone Haliotis discus hannai is an economically valuable mollusk species cultivated in China. However, the modulation of muscle growth by circRNAs in this species is poorly understood. (2) Methods: In this study, we analyzed the muscle transcriptomes of 6 H. discus hannai specimens: three small (S_HD) and three large (L_HD) groups via RNA-seq and bioinformatics technology. (3) Results: The results indicated the presence of 11,744 circRNAs in abalone adductor muscle. Furthermore, the L_HD group had 250 significantly differentially expressed circRNAs (106 upregulated and 144 downregulated) relative to the S_HD group. Moreover, the bioinformatics assessment revealed that circRNAs were related to lipid transporter activity, lipid biosynthetic process, fat digestion and absorption, the single-organism metabolic process, the thyroid hormone signaling pathway, and the hippo signaling pathway, which regulates growth. Seventeen key candidate circRNAs were identified, and a core functional circRNA-miRNA-mRNA network associated with abalone muscle growth was described. Gene expression was verified using qRT-PCR, confirming the accuracy of the RNA-seq data. (4) Conclusion: Overall, this investigation furnishes novel evidence for the potential muscle growth modulatory mechanisms in Pacific abalone. These high-quality circRNA data of abalone muscle provide a reference for functional studies on the abalone genome.