Quantitative proteome profiling reveals molecular hallmarks of egg quality in Atlantic halibut: impairments of transcription and protein folding impede protein and energy homeostasis during early development.

Background: Tandem mass tag spectrometry (TMT labeling-LC-MS/MS) was utilized to examine the global proteomes of Atlantic halibut eggs at the 1-cell-stage post fertilization. Comparisons were made between eggs judged to be of good quality (GQ) versus poor quality (BQ) as evidenced by their subsequent rates of survival for 12 days. Altered abundance of selected proteins in BQ eggs was confirmed by parallel reaction monitoring spectrometry (PRM-LC-MS/MS).

Heterochiasmy and the establishment of gsdf as a novel sex determining gene in Atlantic halibut.

Atlantic Halibut (Hippoglossus hippoglossus) has a X/Y genetic sex determination system, but the sex determining factor is not known. We produced a high-quality genome assembly from a male and identified parts of chromosome 13 as the Y chromosome due to sequence divergence between sexes and segregation of sex genotypes in pedigrees. Linkage analysis revealed that all chromosomes exhibit heterochiasmy, i.

The role of cholecystokinin and peptide YY in feed intake in Atlantic halibut (Hippoglossus hippoglossus) larvae.

Control of appetite and feed intake in fish larvae are still largely unexplored. Two of the key players in controlling vertebrate's feed intake are cholecystokinin (CCK) and peptide YY (PYY). Here we investigated the mRNA expression of pyy, cck and cck receptors (cckr) in the brain (head) and gut of Atlantic halibut larvae in response to three consecutive meals.

Differential developmental toxicity of crude oil in early life stages of Atlantic halibut (Hippoglossus hippoglossus).

To further understand the complexity of developmental toxicity of dispersed oil and importance of exposure timing on fish early life stages, Atlantic halibut (Hippoglossus hippoglossus) were exposed to environmentally relevant concentrations through two embryonic developmental windows: the first period occurred during the epiboly process (named as "early embryonic exposure") and the second period overlapped the ontogenesis and cardiogenesis processes (named as "late embryonic exposure"). Following 72 hour oil exposure, embryos were transferred to clean seawater and a toxicity screening was performed in the yolk-sac larvae until first-feeding stages (56 days). The current study demonstrated that the exposure timing is essential for the development of toxic effects of crude oil in Atlantic halibut.

Structural and functional maturation of skin during metamorphosis in the Atlantic halibut (Hippoglossus hippoglossus).

To establish if the developmental changes in the primary barrier and osmoregulatory capacity of Atlantic halibut skin are modified during metamorphosis, histological, histochemical, gene expression and electrophysiological measurements were made. The morphology of the ocular and abocular skin started to diverge during the metamorphic climax and ocular skin appeared thicker and more stratified. Neutral mucins were the main glycoproteins produced by the goblet cells in skin during metamorphosis.

Vitamin A and arachidonic acid altered the skeletal mineralization in Atlantic cod (Gadus morhua) larvae without any interactions on the transcriptional level.

The main object of this study was to evaluate the impact of different levels of vitamin A (VA) and arachidonic acid (ARA) in relation to eicosapentaenoic acid (EPA) on mineralization and gene expression in Atlantic cod larvae (Gadus morhua). First-feeding larvae were fed enriched rotifers from start-feeding until 29 days post hatch (dph). Larvae in four tanks were fed one of the following diets: control (EPA/ARA ratio: 15.

Neuroendocrine control of appetite in Atlantic halibut (Hippoglossus hippoglossus): changes during metamorphosis and effects of feeding.

Hormones and neuropeptides play a crucial role in the appetite control system of vertebrates, yet few studies have focused on their importance during early teleost development. In this study, we analysed the expression patterns of the appetite-controlling factors ghrelin, neuropeptide Y (NPY), peptide YY (PYY), pro-opiomelanocortin (POMC-C), and cocaine-amphetamine-related transcript (CART) by quantitative PCR. Transcript expression was investigated in response to feeding in developing Atlantic halibut larvae: before (premetamorphic stage 5) and during metamorphosis (stages 8 and 9B), and also in response to a fast-refeed challenge.

Functional modifications associated with gastrointestinal tract organogenesis during metamorphosis in Atlantic halibut (Hippoglossus hippoglossus).

Background: Flatfish metamorphosis is a hormone regulated post-embryonic developmental event that transforms a symmetric larva into an asymmetric juvenile. In altricial-gastric teleost fish, differentiation of the stomach takes place after the onset of first feeding, and during metamorphosis dramatic molecular and morphological modifications of the gastrointestinal (GI-) tract occur. Here we present the functional ontogeny of the developing GI-tract from an integrative perspective in the pleuronectiforme Atlantic halibut, and test the hypothesis that the multiple functions of the teleost stomach develop synchronously during metamorphosis.

Evidence for a regulatory loop between cholecystokinin (CCK) and tryptic enzyme activity in Atlantic cod larvae (Gadus morhua).

In order to maximize protein digestion, the release of enzymes into the gut lumen is closely controlled by a regulatory loop. Cholecystokinin (CCK) is among the enteric hormones that play a key role in the control of digestive enzyme secretion, but its role in first-feeding larvae is still unclear and may differ between species. However, in all marine fish larvae that have not developed a stomach by first-feeding, trypsin is the most important proteolytic enzyme.

Toxic effects of dietary hydrolysed lipids: an in vivo study on fish larvae.

We have previously described that fish larvae absorb a larger fraction of dietary monoacylglycerol than TAG. To investigate how dietary hydrolysed lipids affect a vertebrate at early life stages over time, we fed Atlantic cod (Gadus morhua) larvae six diets with different degrees of hydrolysed lipids for 30 d. The different diets had no effect on growth, but there was a positive correlation between the level of hydrolysed lipids in the diets and mortality.