Reserve lipid

Temperature affects food supply in another way also. The Mediterranean sprat, which prefers cold waters, exploits a wider feeding area than fish that inhabit only warm waters, because it takes advantage of a greater water depth and can feed all the year round. It possesses a much greater lipid reserve than the warm-water anchovy, and its range of fatness over the annual cycle is wider (Figure 36). The feeding conditions in the warm Mediterranean waters are therefore more favourable to fish that prefer cooler waters rather than warm. 

Pre-wintering migration. Metabolism is adjusted to a stable state lipid accumulation and increase in protein are at a standstill the activity of alkaline phosphatase in the scales, which regulates the development of sclerites, decreases markedly the concentration of protein in the blood serum remains stable. During the wintering period, the metabolic activity of the population declines considerably. Lipid reserves decline steadily and tend to exhibit an increased degree of unsaturation in these warm-water fish because of the lower... 

Since the liver changes markedly in size according to its lipid content, the most useful measure is the quantity of lipid in the whole liver, rather than the concentration in a piece of the organ. Where much lipid is stored, the liver is large and creamy in appearance, while the liver of a starved fish is small and red. It must be emphasized that this particular scheme applies only to nonfatty fish, which store virtually all their lipid reserves in their livers. Fatty fish will behave somewhat differently, although die general principles are the same. 

Thus far no sex pheromone has been described in the Phasmida. Some phasmids produce toxic monoterpenes in typical Class III integumentary glands located behind the head (e.g. Happ et al., 1966). The glands exhibit lipid reserves, carboxylic esterases, phosphatases, alcohol dehydrogenase, and a mevalonate kinase, all of which are suggested to be involved in the production of the toxic compounds (Happ et al., 1966). 

When not indicated otherwise, our observations refer to cells in the sub apical area between 300 and 600 pm from the root tip. In the actively growing root, this area is the site of active cell division along with the first stages of cell differentiation, depending on the tissue. Root cells from 2 h-imbibed seeds contained numerous protein bodies19,24 of spheroidal shape, about 1.5-3 pm in diameter and nearly completely filled with highly omiophilic protein material they also contained abundant lipid reserves in the form of minute droplets, mainly concentrated at the cell periphery. The nucleus had spheroid or ellipsoidal shape and showed a distinct nucleolus. The cytoplasm contained numerous mitochondria with a dense matrix as well as relatively small and scarcely differentiated plastids with no or very little starch (Fig. 15.3a,b). 

Electron microscopy of radish radicle, a) and b) Details of cortical cells from radicles of 2 h-imbibed control seeds, (a) Note the abundance of protein reserves in protein bodies (PB) and lipid reserves in the peripheral cytoplasm (arrows), (b) Numerous mitochondria (M) are visible among lipid bodies (L). (c-e) Details of cells from radicles of 16 h-imbibed control seeds, (c) Cortical parenchyma cells. The protein bodies have converted into normal vacuoles (V) and lipid reserves have been partially depleted, (d) Detail of epidermal cell showing a plastid (P) containing starch deposits (S). (e) Detail of cortical cell, showing several mitochondria (M) and a microbody (Mb). 

The treatment with RO fraction slowed down post-imbibition cell development and was directly proportional to the concentration applied. In 1 14-treated roots the protein and lipid reserves were almost completely depleted (Fig. 15.5a). By contrast, in 1 10- and 1 8-roots the vacuolar protein deposits were still abundant, notably in the latter, and lipid reserves appeared to be nearly as abundant as in the 2 h-control roots. 

Kandihan et al (2013) have shown the direct relation of the specific rate of photon absorption with lipid accumulation in the condition of nitrogen starvation, which is known to tri er lipid reserve (ie, TAG) accumulation but also to strongly decrease pigment content, thus altering light absorption by cells. The authors found that a given value of specific rate of photon absorption A was necessary to tri er TAG overaccumulation, and also that TAG synthesis rate was strongly related to A. 

Pouliquen et al. (1997) used NMR technique to study water and lipid reserves in seeds. The temperature dependence of relaxation time was used to identify differences in the thermodynamic properties of water between dry seeds and during germination (Figure 8.3). 

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