Transcriptional dynamic changes in energy metabolism, protein synthesis and cell cycle regulation reveal the biological adaptation mechanisms of juvenile Acrossocheilus wenchowensis under acute temperature changes.

In recent years, frequent acute temperature changes have posed a serious threat to the physiology and survival of fish. This study utilized RNA-Seq technology to analyze the transcriptional dynamics in the muscle tissues of Acrossocheilus wenchowensis under various acute temperature conditions (16◦C, 20◦C, 24◦C, 28◦C and 32◦C). Through comprehensive analysis, we identified 11509 differentially expressed genes (DEGs), a gene set (profiles 19) that was significantly up-regulated with increasing temperature, and two weighted gene co-expression network analysis (WGCNA) modules that were significantly correlated with acute temperature changes. Furthermore, we identified 28 transcription factors that are pivotal in oxidative stress and energy metabolism under acute temperature changes. Our results showed that, compared to the control group (24°C), KEGG functional enrichment analysis revealed significant enrichment of DEGs in the cell cycle, DNA replication, and p53 signaling pathway, with an overall trend of suppressed expression. This indicates that maintaining cell stability and reducing cell damage is an effective adaptive mechanism for A. wenchowensis to cope with acute temperature changes. Through STEM analysis and the black WGCNA module associated with high-temperature stress, we identified significant up-regulation of pathways and hub genes related to energy metabolism including oxidative phosphorylation, TCA cycle, purine metabolism, and glutathione metabolism, as well as the central roles of signal transduction pathways such as MAPK signaling pathway and AMPK signaling pathway, which synergistically regulate energy production. Under acute low-temperature stress, the turquoise WGCNA module highlighted significant up-regulation of hub genes associated with Ribosomal and Spliceosomal pathways related to protein synthesis and processing, as well as activation of calcium signaling pathways, which plays an important role in maintaining cellular function during low-temperature adaptation. These findings provide a critical theoretical and molecular basis for the adaptation of eurythermal fish to rapid temperature changes.

The complete mitochondrial genome of Neolissochilus soroides (Duncker, 1904) (Cypriniformes: Cyprinidae).

In this paper, we first report the complete mitochondrial genome of Neolissochilus soroides. The main purpose of this study was to determine the mitochondrial genome and phylogenetic status of N. soroides. The length mitogenome was 16584 bp, containing 2 ribosomal RNA genes, 13 protein-coding genes, 22 transfer RNA genes, and 3 non-coding control regions. The genome showed a slight A + T bias (A + T = 56.47%). 12 genes (ND1, COX2, ATP6, ND4L, ND5, ND6, ND2, ATP8, ND3, ND4, Cytb, COX3) start with ATG codon, besides one gene (COX1) start with GTG codon. Six genes (ND1, COX1, ATP6, ND4L, ND5, ND6) end with a TAA codon, 3 genes (ND2, ATP8, ND3) end with a TAG codon, and four genes (COX2, ND4, Cytb, COX3) end with the TA or T codon. The phylogenetic analysis showed that N. soroides was closely related to N. hendersoni. The mitogenome could have important implications for phylogeny, population genetics, and conservation of the N. soroides.