Project description:The Antarctic krill provides central ecosystems services to the Southern Ocean grazing on autotroph and heterotoph diet and constituting the dominant food source for higher trophic levels. Moreover, E. superba's extensive equipment with biomacromolecule hydrolysing enzymes represents a largely untapped resource for applied purposes. The proteome compendium of krill provides a valuable basis for future studies on krill biology (e.g., metabolism, development, migration behaviour), for krill's contribution to organic matter turnover in the Southern Ocean, as well as for multilevel biotechnological prospecting.
Project description:The Antarctic krill provides central ecosystems services to the Southern Ocean grazing on autotroph and heterotoph diet and constituting the dominant food source for higher trophic levels. Moreover, E. superba's extensive equipment with biomacromolecule hydrolysing enzymes represents a largely untapped resource for applied purposes. The proteome compendium of krill provides a valuable basis for future studies on krill biology (e.g., metabolism, development, migration behaviour), for krill's contribution to organic matter turnover in the Southern Ocean, as well as for multilevel biotechnological prospecting.
Project description:The Antarctic krill provides central ecosystems services to the Southern Ocean grazing on autotroph and heterotoph diet and constituting the dominant food source for higher trophic levels. Moreover, E. superba's extensive equipment with biomacromolecule hydrolysing enzymes represents a largely untapped resource for applied purposes. The proteome compendium of krill provides a valuable basis for future studies on krill biology (e.g., metabolism, development, migration behaviour), for krill's contribution to organic matter turnover in the Southern Ocean, as well as for multilevel biotechnological prospecting.
Project description:The Antarctic krill provides central ecosystems services to the Southern Ocean grazing on autotroph and heterotoph diet and constituting the dominant food source for higher trophic levels. Moreover, E. superba's extensive equipment with biomacromolecule hydrolysing enzymes represents a largely untapped resource for applied purposes. The proteome compendium of krill provides a valuable basis for future studies on krill biology (e.g., metabolism, development, migration behaviour), for krill's contribution to organic matter turnover in the Southern Ocean, as well as for multilevel biotechnological prospecting
Project description:The Antarctic krill provides central ecosystems services to the Southern Ocean grazing on autotroph and heterotoph diet and constituting the dominant food source for higher trophic levels. Moreover, E. superba's extensive equipment with biomacromolecule hydrolysing enzymes represents a largely untapped resource for applied purposes. The proteome compendium of krill provides a valuable basis for future studies on krill biology (e.g., metabolism, development, migration behaviour), for krill's contribution to organic matter turnover in the Southern Ocean, as well as for multilevel biotechnological prospecting.
2022-09-28 | PXD033775 | Pride
Project description:Diet composition of krill and salps in the Southern Ocean
Project description:The experiment aimed to investigate seasonal and regional differences in gene expression in Antarctic krill in three different latitudinal regions of the Southern Ocean with variable photoperiodic conditions: South Georgia (54°S), South Orkneys/Bransfield Strait (60°S-63°S) and Lazarev Sea (62°S -66°S). An RNAseq approach was used to test for (1) seasonal differences in gene expression between summer and winter krill from each region, and (2) regional differences in gene expression between the three different regional krill samples from each season. The RNAseq data was analysed with the goal to identify potential seasonal target genes with regulatory functions in the seasonal life cycle of Antarctic krill, focussing on genes related to regulation, reproduction, development and visual perception.
Project description:Antarctic krill (Euphausia superba) is a high latitude pelagic organism which plays a central role in the Southern Ocean ecosystem. E. superba shows daily and seasonal rhythms in physiology and behaviour, which are synchronized with the environmental cycles of its habitat. Recently, the main components of the krill circadian machinery have been identified and characterized. However, the exact mechanisms through which the endogenous timing system operates the control and regulation of the overt rhythms remains only partially understood. Here we investigate the involvement of the circadian clock in the temporal orchestration of gene expression by using a newly developed version of a krill microarray platform. The analysis of transcriptome data from krill exposed to both light-dark cycles (LD 18:6) and constant darkness (DD), has led to the identification of 1,564 putative clock-controlled genes. A remarkably large proportion of such genes, including several clock components (clock, period, cry2, vrille, and slimb), show oscillatory expression patterns in DD, with a periodicity shorter than 24 hours. Energy-storage pathways appear to be regulated by the endogenous clock in accordance with their ecological relevance in daily energy managing and overwintering. Our results provide the first representation of the krill circadian transcriptome under laboratory, free-running conditions. This SuperSeries is composed of the SubSeries listed below.
Project description:The inclusion of intact phospholipids in the diet is essential during larval development and can improve culture performance of many fish species. The effects of supplementation of dietary phospholipid from marine (krill) or plant (soy lecithin) sources were investigated in Atlantic salmon, Salmo salar. First feeding fry were fed diets containing either krill oil supplying phospholipid at 2.6% of diet (named K2.6) or soybean lecithin supplying phospholipid at 2.6 % (S2.6), 3.6 % (S3.6) of diet. A control diet (B) without supplemented phospholipid was also supplied. Fish were sampled at ~ 2.5 g (~1990 ˚ day post fertilization, dpf) and ~10 g (2850 ˚dpf). By comparison of the intestinal transcriptome in specifically chosen contrasts, it was determined that by 2850˚dpf fish possessed a profile that resembled that of mature and differentiated intestinal cell types with a number of changes specific to glycerophospholipid metabolism. It was shown that intact phospholipids and particularly phosphatidylcholine are essential during larval development and that this requirement is associated with the inability of enterocytes in young fry to endogenously synthesize sufficient phospholipid for the efficient export of dietary lipid. In the immature phase (~1990 ˚dpf), the dietary phospholipid content as well as its class composition impacted on several biochemical and morphological parameters including growth, but these differences were not associated with differences in intestinal transcriptomes. The results of this study have made an important contribution to our understanding of the mechanisms associated with lipid transport and phospholipid biosynthesis in early life stages of fish.
Project description:Dietary supplementation with ω-3 polyunsaturated fatty acids (ω-3 PUFAs), specifically the fatty acids docosahexaenoic acid (DHA; 22:6 ω-3) and eicosapentaenoic acid (EPA; 20:5 ω-3), is known to have beneficial health effects including improvements in glucose and lipid homeostasis and modulation of inflammation. To evaluate the efficacy of two different sources of ω-3 PUFAs, we performed gene expression profiling in the liver of mice fed diets supplemented with either fish oil or krill oil. We found that ω-3 PUFA supplements derived from a phospholipid krill fraction (krill oil) downregulated the activity of pathways involved in hepatic glucose production as well as lipid and cholesterol synthesis. The data also suggested that krill oil-supplementation increases the activity of the mitochondrial respiratory chain. Surprisingly, an equimolar dose of EPA and DHA derived from fish oil modulated fewer pathways than a krill oil-supplemented diet and did not modulate key metabolic pathways regulated by krill oil, including glucose metabolism, lipid metabolism and the mitochondrial respiratory chain. Moreover, fish oil upregulated the cholesterol synthesis pathway, which was the opposite effect of krill supplementation. Neither diet elicited changes in plasma levels of lipids, glucose or insulin, probably because the mice used in this study were young and were fed a low fat diet. Further studies of krill oil supplementation using animal models of metabolic disorders and/or diets with a higher level of fat may be required to observe these effects. Twenty-one microarrays: three diets (CO, FO, KO) x seven mice per diet x one microarray per mouse