Liver Transcriptome Changes in Zebrafish during Acclimation to Transport-Associated Stress

Abstract

Liver plays a key role during the stress acclimation, and liver transcriptome analysis of shipped zebrafish could reveal the molecular adjustments that occur in the organ. Transcriptional changes in liver were analyzed with a 44 K oligo array using total RNA from fish prior to transport and during a mock transport process - immediately after packing (0 h), at 48 and 72 h. Large numbers of genes related to a variety of biological processes and pathways were regulated, mainly during transport (at 48/72 h). Immediately after packing, transcripts of genes related to both gluconeogenesis and glycolysis were induced. During transport, induction of gluconeogenesis-linked genes and reduction of glycolysis-related genes may be supporting the increase in blood glucose levels. Inhibition of genes involved in fatty acid beta-oxidation may be pointing to the poor ability of fish to utilize energy from fatty acids, under transport conditions. Genes involved in some of the mechanisms that regulate body ammonia were also affected. Even though genes associated with certain transaminases were inhibited in liver, sustained glutamate deamination may have led to high ammonia accumulation in liver/body. Enhanced levels of gene transcripts in ubiquitination and MAPK signalling cascade and reduced levels of gene transcripts related to ROS generation via peroxisomal enzymes as well as xenobiotic metabolism may be signifying the importance of such cellular and tissue responses to maintain homeostasis. Furthermore, transcripts connected with stress and thyroid hormones were also regulated. Moreover, suppression of genes related to specific immune components may be denoting the deleterious impact of transport on fish health. Thus, this study has revealed the complex molecular -adjustments that occur in zebrafish when they are transported.

Fasting enhances cold resistance in fish through stimulating lipid catabolism and autophagy

“…The majority of assays were mainly performed on samples from fish liver or liver cells because the liver plays central roles in metabolism and homeostatic processes in fish (Dhanasiri et al . ). The fed fish (control), fed cold‐stressed (control‐cold), fasting and fasting cold‐stress groups are designated C, CC, F and FC, respectively.…”

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

“…Among them, we can cite immune sup- pression, stimulated protein catabolism, and gluconeogenesis (Baldisserotto 2009). 3, plasma cortisol increases markedly during the transport of fish (Gomes et al 2003;Acerete et al 2004;Urbinati and Carneiro 2006;Dhanasiri et al 2013b). 3, plasma cortisol increases markedly during the transport of fish (Gomes et al 2003;Acerete et al 2004;Urbinati and Carneiro 2006;Dhanasiri et al 2013b).…”

“…Other markers or approaches A recent complementary approach to the use of classical physiological markers is that of transcriptomics (Dhanasiri et al 2013b). Authors of this study have verified, during the transport of zebrafish, changes in the expression of genes involved in the metabolism of the stress response, such as enzymes involved in (i) gluconeogenesis and glycolysis, (ii) beta-oxidation of fatty acids, (iii) regulation of ammonia, (iv) the cellular stress response (ubiquitin and MAP kinases) and still, the immunological system, which belongs to the class of tertiary stress responses (Dhanasiri et al 2013a, b).…”

Deiodinases and thyroid metabolism disruption in teleost fish

“…The HPT axis is sensitive to several physical environmental factors (Dhanasiri et al, 2013;Li et al, 2012;Little et al, 2013), which may modulate the pathway in different ways depending on whether they act alone or in combination (Sinha et al, 2012). Salinity, water flow, food intake, light period, temperature and stress are some of the most relevant factors known to alter deiodination (Table 1).…”