Characterization and analysis of transcriptome complexity using SMRT-Seq combined with RNA-Seq for a better understanding of Acanthogobius ommaturus in response to temperature stress

Responses of the mud snail Cipangopaludina cathayensis to thermal stress: Insights from metabolism, oxidative stress damage, and hepatopancreas transcriptional modulation

Global warming linked to climate change poses a significant risk to aquatic animals. Invertebrates, such as Cipangopaludina cathayensis are especially susceptible to elevated temperature. Understanding how C. cathayensis responds to high-temperature stress is crucial for predicting the putative effects of climate change on its cultivation. In this study, we exposed C. cathayensis to various temperature conditions (26 °C, 28 °C, 30 °C, and 32 °C) for 3 h, revealing that both oxygen consumption and ammonia excretion rates increased gradually with increasing temperature, reaching maximum values of 77.711 ± 2.364 μg·(g·h)-1 and 4.701 ± 0.036 μg·(g·h)-1 at 30 °C and 28 °C, respectively. However, values of these parameters decreased when the culture temperature increased to 32 °C. High-temperature stress also resulted in a reduced O:N ratio and decreased energy metabolism rate. To investigate how high temperature impacts antioxidant activities, immune function, and transcriptional regulation in the hepatopancreas, C. cathayensis were exposed to temperatures of 26 °C or 32 °C for 3 and 7 days, respectively. Our results indicated that high temperature disrupted the antioxidant defense system and led to immunosuppression in the hepatopancreas. Comparative transcriptome analysis identified 6638 genes with significantly altered expression between these two temperature groups. Functional enrichment analysis of differentially expressed genes demonstrated that high temperature affected protein homeostasis, energy metabolism, and immune function of C. cathayensis. Together, these findings offer valuable information for evaluating the impacts of global warming on the culture of mud snail.

Comparative transcriptomic analysis revealed changes in multiple signaling pathways involved in protein degradation in the digestive gland of Mytilus coruscus during high-temperatures

As a result of global warming, the Mytilus coruscus living attached in the intertidal zone experience extreme and fluctuating changes in temperature, and extreme temperature changes are causing mass mortality of intertidal species. This study explores the transcriptional response of M. coruscus at different temperatures (18 °C, 26 °C, and 33 °C) and different times (0, 12, and 24 h) of action by analyzing the potential temperature of the intertidal zone. In response to high temperatures, several signaling pathways in M. coruscus, ribosome, endocytosis, endoplasmic reticulum stress, protein degradation, and lysosomes, interact to counter the adverse effects of high temperatures on protein homeostasis. Increased expression of key genes, including heat shock proteins (Hsp70, Hsp20, and Hsp110), Lysosome-associated membrane glycoprotein (LAMP), endoplasmic reticulum chaperone (BiP), and baculoviral IAP repeat-containing protein 7 (BIRC7), may further mitigate the effects of heat stress and delay mortality in M. coruscus. These results reveal changes in multiple signaling pathways involved in protein degradation during high-temperature stress, which will contribute to our overall understanding of the molecular mechanisms underlying the response of M. coruscus to high-temperature stress.

Regulating Strategies of Transcription and Alternative Splicing for Cold Tolerance Harpadon nehereus Fish

In recent years, Harpadon nehereus gradually become a dominant species with great potential for exploitation in the East China Sea, and it is worth investigating whether H. nehereus would tolerate cold stress to continue to expand into the colder northern waters. The molecular regulation level is favorable evidence to explore the cold tolerance of H. nehereus, a total of 6,650, 1,936, and 2,772 differentially expressed genes (DEGs) in transcription regulation, and 4,409, 1,250, and 2,303 differential alternative splicing genes (DASGs) in alternative splicing regulation were identified in H. nehereus at 13, 15, and 17°C, respectively, importantly, 47 genes were identified as the key candidate genes for cold tolerance in H. nehereus. In transcription regulation, up-regulated DEGs were enriched in metabolic process terms and ribosome, spliceosome pathway, etc., while down-regulated DEGs were enriched in signal transduction terms, focal adhesion, proteoglycans in cancer pathway, etc., at 13, 15, and 17°C, respectively. In alternative splicing regulation, spliceosome, mRNA surveillance pathway, etc., were significantly enriched in DASGs. In a word, H. nehereus adapts to cold environments mainly through transcription and translation, transmembrane transport, protein modification, etc., while cold stress may also induce some diseases in H. nehereus.