Integrated analysis of transcriptome, translatome and proteome reveals insights into yellow catfish (Pelteobagrus fulvidraco) brain in response to hypoxia.

Brain plays a central role in adapting to environmental changes and is highly sensitive to the oxygen level. Although previous studies investigated the molecular response of brain exposure to acute hypoxia in fish, the lack of studies at the translational level hinders further understanding of the regulatory mechanism response to hypoxia from multi-omics levels. Yellow catfish (Pelteobagrus fulvidraco) is an important freshwater aquaculture species; however, hypoxia severely restricts the sustainable development of its breeding industry. In the present study, the transcriptome, translatome, and proteome were integrated to study the global landscapes of yellow catfish brain response to hypoxia. The evidently increased amount of cerebral cortical cells with oedema and pyknotic nuclei has been observed in hypoxia group of yellow catfish. A total of 2750 genes were significantly changed at the translational level. Comparative transcriptional and translational analysis suggested the HIF-1 signaling pathway, autophagy and glycolysis/gluconeogenesis were up-regulated after hypoxia exposure. KEGG enrichment of translational efficiency (TE) differential genes suggested that the lysosome and autophagy were highly enriched. Our result showed that yellow catfish tends to inhibit the TE of genes by increasing the translation of uORFs to adapt to hypoxia. Correlation analysis showed that transcriptome and translatome exhibit higher correlation. In summary, this study demonstrated that hypoxia dysregulated the cerebral function of yellow catfish at the transcriptome, translatome, and proteome, which provides a better understanding of hypoxia adaptation in teleost.

Effects of acute hypoxia and reoxygenation on oxygen sensors, respiratory metabolism, oxidative stress, and apoptosis in hybrid yellow catfish "Huangyou-1".

The regulation mechanism of the hybrid yellow catfish "Huangyou-1" was assessed under conditions of hypoxia and reoxygenation by examination of oxygen sensors and by monitoring respiratory metabolism, oxidative stress, and apoptosis. The expressions of genes related to oxygen sensors (HIF-1α, HIF-2α, VHL, HIF-1ß, PHD2, and FIH-1) were upregulated in the brain and liver during hypoxia, and recovered compared with control upon reoxygenation. The expressions of genes related to glycolysis (HK1, PGK1, PGAM2, PFK, and LDH) were increased during hypoxia and then recovered compared with control upon reoxygenation. The mRNA levels of CS did not change during hypoxia in the brain and liver, but increased during reoxygenation. The mRNA levels of SDH decreased significantly only in the liver during hypoxia, but later increased compared with control upon reoxygenation in both tissues. Under hypoxic conditions, the expressions of genes related to oxidative stress (SOD1, SOD2, GSH-Px, and CAT) and the activity of antioxidant enzymes (SOD, CAT, and GSH-Px) and MDA were upregulated compared with control. The expressions of genes related to apoptosis (Apaf-1, Bax, Caspase 3, Caspase 9, and p53) were higher than those in control during hypoxic exposure, while the expressions of Bcl-2 and Cyt C were decreased. The findings of the transcriptional analyses will provide insights into the molecular mechanisms of hybrid yellow catfish "Huangyou-1" under conditions of hypoxia and reoxygenation. Overall, these findings showed that oxygen sensors of "Huangyou-1" are potentially useful biomarkers of environmental hypoxic exposure. Together with genes related to respiratory metabolism, oxidative stress and apoptosis occupy a quite high position in enhancing hypoxia tolerance. Our findings provided new insights into the molecular regulatory mechanism of hypoxia in "Huangyou-1."

Novel biomass-derived smoke-like carbon as a supercapacitor electrode material.

In this present work, smoke-like carbon was successfully fabricated from a bio-waste fungal substrate crude polysaccharide for the first time. The as-prepared products possess smoke-like structures, ultra-high specific surface area (S BET: 2160 m2 g-1) and a high content of micropores (microporous surface area of 60%, with a nanopore size of 0.70 nm), which can increase the specific capacitance, representing a wonderful structure for electrochemical energy storage devices. The as-prepared sample displayed an excellent specific capacitance of 152 F g-1 at 5 A g-1 in the three-electrode configuration and exhibited maximal densities of 6.8-10.2 W h kg-1 under power outputs of 253.4-24.3 kW kg-1. We believe that this work demonstrates a simple, green and low-cost route by using agricultural residue to prepare applicable carbon materials for use in energy storage devices.