Search

Hypoxia, a common environmental condition, can affect cell survival and physiological function by triggering oxidative stress. Akt/FoxO pathway has been proven to play a non-negligible role in the regulation of autophagy. However, the role of Akt/FoxO pathway in hypoxia-induced autophagy is unclear in fish. Therefore, in this study, grass carp hepatocyte cells (L8824) were treated by CoCl2 to simulate hypoxia, and the results showed that CoCl2 can increase the expression of Hif-1a protein at different concentrations or different treatment time. Further study found that hypoxia increased intracellular reactive oxygen species (ROS) level, and the expression of autophagy-related genes (LC3-II, pink1, beclin-1 and p62) and foxO1a/1b. The mitochondrial membrane potential (ΔΨm) was also depolarized, and autophagosomes were intriguingly detected by transmission electron microscope (TEM) after the treatment of hypoxia. Moreover, hypoxia inhibited Akt phosphorylation, while PI3K/Akt pathway inhibitor, LY294002 significantly up-regulated the expression of foxO1a/1b and autophagy-related genes. Additionally, silencing foxo1b also resulted in down-regulation of autophagy-related genes. It was demonstrated that hypoxia induced autophagy via Akt/FoxO1 pathway. These results will provide a new light on further understanding the role of Akt/FoxO pathway in the response to hypoxia in fish. [ABSTRACT FROM AUTHOR]

To understand the current status of germplasm resources of Penaeus japonicus, in this study, genetic diversity was analyzed based on morphometric analysis and fluorescent microsatellite markers. For morphometric analysis, the cumulative ratios of the PC1 and PC2 (85.90%) were greater than 75%, which can explain the morphological variation among populations. For microsatellite analysis, the allele number in 10 microsatellite loci ranged from 27 to 53, and the effective allele number ranged from 21 to 42. The observed heterozygosity ranged from 0.463 to 0.983, whereas expected heterozygosity ranged from 0.932 to 0.966, and the average polymorphism information content was 0.947, which indicated a high level of genetic diversity. The unbiased genetic distance among populations ranged from 0.230 to 0.431, and the genetic similarity coefficient ranged from 0.654 to 0.782. Analysis of molecular variance (AMOVA) showed that the genetic variation within individuals was the main source of variation, accounting for 88.55%, and only 1.49% of the genetic variation came from among populations. [ABSTRACT FROM AUTHOR]