Enzymes of lipogenesis

Segner, Helmut; Böhm, R.

doi:10.1016/b978-0-444-82033-4.50033-7

Cited by 22 publications

(22 citation statements)

References 22 publications

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“…Regardless of the dietary treatment, the highest lipid content was found in liver followed by whole body (including adipose tissue) and flesh. Increasing lipid content of liver in the present study might be associated with the lipogenesis activity in this organ since the liver is the main site for lipogenesis, followed by other tissues (Segner and Böhm, 1994). Numerous studies, in a wide range of fish species, have shown that flesh fatty acid composition is closely correlated to dietary fatty acid composition and that feeding high levels of vegetable oils will strongly influence the preferential deposition and retention of "unwanted" fatty acids such as 18:2n− 6 and 18:3n− 3 in flesh lipids.…”

Section: Tablementioning

confidence: 80%

Effects of alternate feeding with different lipid sources on fatty acid composition and bioconversion in European sea bass (Dicentrarchus labrax)

et al. 2016

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Section: Tablementioning

confidence: 80%

Effects of alternate feeding with different lipid sources on fatty acid composition and bioconversion in European sea bass (Dicentrarchus labrax)

et al. 2016

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“…Larval DNA concentrations can be regarded as an estimate for the number of cells per weight, whereas the ratio protein/DNA reflects more the size of a cell (Foster et al 1993;B6hm et al 1994). With values between 1.97 and 2.69 itg DNA mglarval weight, the DNA concentrations were slightly higher in fishes receiving dry food than in larvae fed on Artemia (1.73-2.11 g DNA mg-1 larval weight; Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…A change of maximum enzyme activities reveals an altered demand for the related metabolic function (Newsholme and Paul 1983;Moon and Mommsen 1987;Kiessling et al 1991). This methodological approach has been used in numerous studies on the influence of environmental factors on fish metabolism (e.g., Mommsen et al 1980;Cowey et al 1981;Hilton and Atkinson 1982;Moon 1983;Walton 1986;Lupianez et al 1989;Walzem et al 1991;B6hm et al 1994;Pelletier et al 1994). This approach is applied in the present study to analyse metabolic ontogeny in larval C. gariepinus reared under different nutritional conditions.…”

Section: Discussionmentioning

confidence: 99%

“…The analysis of DNA and RNA followed the method of Rafael and Vsianski (1981). From these data, it was calculated the DNA/weight ratio as an estimate of cell number per unit weight, the protein/DNA ratio as an estimate of the cell size, and the RNA/DNA ratio as an estimate of the amount of RNA per cells (Foster et al 1993;B6hm et al 1994).…”

Section: Other Methodsmentioning

confidence: 99%

“…1.1.1.40, measured according to Segner and B6hm 1994): 50 mM Tris, pH 7.5, 8.4 mM MgCI 2 , 0.4 mM NADP +; start by 1 mM malate; reaction was monitored by following the generation of NADPH at 340 nm.…”

Section: Enzyme Analysesmentioning

confidence: 99%

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Metabolic enzyme activities in larvae of the African catfish, Clarias gariepinus: changes in relation to age and nutrition

Segner

Verreth²

1995

Fish Physiol Biochem

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The influence of ontogeny and nutrition on metabolic enzyme activities in larvae of the African catfish, Clarias gariepinus, was studied. After start of exogenous feeding, the larvae were reared for 10 days under three different nutritional conditions: Artemia nauplii, a dry starter diet, and starvation. The live feed gave the best growth (96 mg within 10 days) whereas the dry diet resulted in low growth (33 mg). This growth difference was reflected in larval RNA and DNA concentrations, but not in the levels of soluble protein. Enzymes representing the following aspects of metabolism have been analysed: NADPH generation (G6PDH, ME), glycolysis (PFK, PK), gluconeogenesis (FDPase), amino acid catabolism (GOT, GPT) and oxidative catabolism (CS). All enzymes were present from the start of exogenous feeding onwards, but their maximum specific activities displayed different developmental patterns. In catfish larvae fed on Artemia, G6PDH and ME activities steadily increased with age and weight of the larvae. CS levels remained, after an immediate enhancement upon onset of exogenous feeding, on a rather stable plateau. The amino acid-degrading enzymes GOT and GPT showed maximum levels at days 3-5 of feeding or at a body weight of 10-20 mg, but decreased thereafter. Activities of PFK, PK and FDPase showed low initial levels, and increased significantly with age and size. Based on the ontogenetic patterns of metabolic enzymes, in C. gariepinus larvae an early and a late developmental phase can be distinguished. During the early phase, the glycolytic and gluconeogenetic capacities are low, whereas they are enforced during the later phase. The oxidative capacity is high both during the early and the late phase. The metabolic changes in catfish development coincide with other major ontogenetic events, e.g., alterations of muscle organization, gill morphology, respiration and stomach structure and function. Rearing catfish larvae on a dry diet instead of Artemia partly altered the developmental pattern described: The ontogenetic elevation of CS, PFK and FDPase was delayed and the early peak in GOT and GPT activities was not realized. Particularly during the early developmental phase, the enzyme behaviour of the larvae fed on dry food was similar to that of starved larvae.

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De novo biosynthesis of linoleic acid is widespread in parasitic wasps

Broschwitz

Prager

Pokorny

et al. 2021

Arch Insect Biochem Physiol

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Linoleic acid (C18:2 Δ9,12 , LA) is an important metabolite with numerous essential functions for growth, health, and reproduction of organisms. It has long been assumed that animals lack Δ12-desaturases, the enzymes needed to produce LA from oleic acid (C18:1 Δ9 , OA). There is, however, increasing evidence that this is not generally true for invertebrates. In the insect order Hymenoptera, LA biosynthesis has been shown for only two parasitic wasp species of the so-called "Nasonia group," but it is unknown whether members of other taxa are also capable of synthesizing LA. Here, we demonstrate LA biosynthesis in 13 out of 14 species from six families of parasitic wasps by gas chromatography-mass spectrometry analysis using two different stable isotope labeling techniques. Females of the studied species converted topically applied fully 13 C-labeled OA into LA and/or produced labeled LA after feeding on fully 13 C-labeled α-D-glucose. These results indicate that Δ12-desaturases are widespread in parasitic Hymenoptera and confirm previous studies demonstrating that these insects are capable of synthesizing fatty acids de novo.

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Enzymes of lipogenesis

Cited by 22 publications

References 22 publications

Effects of alternate feeding with different lipid sources on fatty acid composition and bioconversion in European sea bass (Dicentrarchus labrax)

Effects of alternate feeding with different lipid sources on fatty acid composition and bioconversion in European sea bass (Dicentrarchus labrax)

Metabolic enzyme activities in larvae of the African catfish, Clarias gariepinus: changes in relation to age and nutrition

De novo biosynthesis of linoleic acid is widespread in parasitic wasps

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