Tissue Distribution and Nutritional Regulation of Fatty Acid-Binding Proteins (fabps) in Two Marine Teleosts, Turbot (Scophthalmus maximus), and Tiger Puffer (Takifugu rubripes)

Abstract

Fatty acid-binding proteins (fabps) play important roles in lipid homeostasis. In the present study, 7 fabp isoforms, namely, fabp1, fabp2, fabp3, fabp4, fabp6, fabp7, and fabp10, in two marine teleosts, were characterized. In general, turbot and tiger puffer fabp genes showed high identity to their orthologs in other fish species and mammals, but tiger puffer Fabp6 shared the lowest identity to its known orthologs in zebrafish and human. The tissue distribution patterns of fabps were generally in accordance with their function features. However, tiger puffer fabps, in particular Fabp1, Fabp2, Fabp6 and Fabp7, may have functions distinct from other teleosts, as indicated by the phylogenetic tree and tissue distribution patterns. In both species, high dietary lipid levels downregulated the expression of fabp2, fabp3, fabp6, and fabp7a but tended to upregulate the fabp1 expression. Starvation downregulated the expression of most fabps in both fish species, but the downregulation of fabp expression in turbot was much more drastic and earlier compared to tiger puffer. Long-term (30-day) starvation increased the fabp7 expression in tiger puffer and tended to increase the fabp6 expression in turbot. Results of this study contribute to fish fabp physiology and its nutritional regulation.

Tissue distribution and nutritional regulation of peroxisomal fatty acid β‐oxidation genes: A preliminary study in two marine teleosts, turbot ( Scophthalmus maximus ) and tiger puffer ( Takifugu rubripes )

“…Compared with turbot, tiger puffer with lower lipid content in the muscle had early peaks of peroxisomal β-oxidation gene expression during starvation. Similar results were also observed in a recent study on the transcription of fatty acid-binding proteins in these two fish species (Wang et al, 2022).…”

“…The average initial body weight of turbot and tiger puffer was 26 and 19.5 g respectively. The two fish species were fed nearly identical experimental diets (Wang et al, 2022). Briefly, the experimental diets contained different lipid levels (8.0%, 12.0% and 16.0% of dry weight), designated as LL (low lipid level, control), ML (moderate lipid level) and HL (high lipid level) respectively.…”

“…The methods for RNA extraction, cDNA synthesis, quantitative real time‐polymerase chain reaction analysis, and statistical analysis were performed according to the procedure described previously (Wang et al, 2022). The sequences of specific primers used were presented in Table 1.…”

“…The methods for collection of fish tissue samples used in this study were described previously (Wang et al, 2022). Briefly, brain (B), eye (E), gill (G), skin (Sk), muscle (M), heart (H), kidney (K), liver (L), stomach (St), spleen (Sp), pyloric caecum (P), anterior intestine (AI), mid intestine (MI) and hind intestine (HI) were collected from 30 juvenile turbot (10 fish as a replicate pool), and brain (B), eye (E), muscle (M), skin (Sk), heart (H), liver (L), spleen (Sp) and intestine (I) were collected from 15 juvenile tiger puffer (5 fish as a replicate pool).…”

Fatty acid–binding protein genes in gilthead seabream: molecular cloning and nutritional regulation under low water temperatures

“…FABPs are also involved in the ß‐oxidation of fatty acids (FAs), so they play pivotal functions in lipid homeostasis. Nonetheless, the functions of FABPs have not yet been fully determined (Chen et al ., 2012; Taşbozan et al ., 2022; Venkatachalam et al ., 2009; Wang et al ., 2022). Earlier reports have suggested a different ligand‐binding specificity for each fabp gene (Storch & Thumser, 2010).…”