In vivo studies of [1- 14C] fatty acid metabolism in rotifer (Brachionus plicatilis ) and Artemia (Artemia sp.)

Autor: Reis, Diana B., Pérez, José A., Ramírez, Daniel, Acosta, Nieves Guadalupe, Jerez, Salvador, Navarro, Juan Carlos, Rodríguez, Covadonga
Přispěvatelé: Gobierno de Canarias
Rok vydání: 2021
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
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Popis: Trabajo presentado en la International Conference & Exposition Aquaculture Europe, celebrada en Funchal, Maderia (Portugal) del 04 al 07 de octubre de 2021.
[Introduction]: Despite the recent progresses in the development of inert diets, the rearing of early life stages of aquatic organisms still depends on the use of live feeds. Within live feeds, rotifer (Brachionus plicatilis) and Artemia sp. are widely used in the rearing of marine larvae due to their high availability and acceptance by a large number of species. Nonetheless, both live preys naturally possess low content of long-chain polyunsaturated fatty acids (LC-PUFA) such as 20:5n-3 (EPA), and 22:6n-3 (DHA), which are essential fatty acids for proper development of marine fish larvae. In this respect, enrichment of live preys is used to tailor its lipid composition towards the nutritional needs of marine larvae. To improve the design of live prey enrichment protocols, it is advisable to unveil the metabolic fate of fatty acids (FA) during the enrichment process. Therefore, the aim of the present study was to determine the in vivo capability of rotifers and Artemia metanauplii to incorporate and transform unsaturated FA.
[Material and methods]: Incubations 75 000 rotifers (Strain S1 fed with baker’s yeast, Saccharomyces cerevisiae) 75 cm2 tissue culture flasks (Sarstedt AG & Co.) 50 mL of filtered water (20 ppt) 10 000 metanauplii (Artemia Cyst EG - INVE AQUACULTURE) 6-well flat-bottom tissue culture plates (Sarstedt AG & Co.) 10 mL of sea water 5 hours incubation 0.2 µCi (0.3 µM) of [1- 14C]-FA bound to BSA N=4 Incorporation and FA transformation analysis Incorporation of [1-14C]-FA into total lipids (TL) (Reis et al., 2017) [1-14C]-FA transformation (Exposure Cassete-K and Image Screen-K, BioRad) Image acquisition (Molecular Imager FX, BioRad) FA quantification (Quantity One 4.5.2 1-D analysis software, BioRad).
[Results]: Most notably, the incorporation of [1- 14C]DHA into live preys TL was approximately half to third of the incorporation of all other radiolabeled FA substrates. Data are presented in pmoles of 14C fatty acid incorporated per mg of protein per hour of incubation. Incorporation of [1- 14C]-FA into total lipids
[Discussion]: Similarly to what was reported by Lubzens et al. (1985), the results of the present study showed the capacity of rotifers to elongate and desaturate dietary FA, being this organism able to biosynthesize LC-PUFA from their C18 FA precursors. Besides, when [1-14C]OA was added to the incubation media, the biosynthesis of LA and ALA, showing Δ12 and Δ15 desaturase activities, and of ARA, EPA and DHA, indicating the activity of other ꞷ3 desaturases (Δ17 and Δ19) over C20 and C22 FA substrates, was detected. These results agree well with those of Kabeya et al. (2018), who showed the existence of Δ12 and ꞷ3 desaturase enzymes, in the rotifer Adineta vaga by functional characterization. This capacity would theoretically favor the accomplishment of tangible n-3 LC-PUFA content in rotifers’ tissues, and consequently the potential attainment of DHA and EPA requirements of marine fish larvae, even when enriched with vegetable oils (rich in LA and ALA). In contrast, the null capacity of Artemia metanauplii to biosynthesize LC-PUFA and its preferential catabolism of DHA (Guinot et al., 2013; Reis et al., 2017) highlights the reported difficulties for an efficient enrichment protocol for Artemia as food for larvae of marine organisms.
MACBIOBLUE (MAC/1.1b/086). C.R. is a member of ITB (Canary Islands)
Databáze: OpenAIRE
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