Protein metabolism during sexual maturation in female Atlantic salmon (Salmo salar L)

Abstract

Body composition and fractional rates of protein synthesis (percentage of the protein mass synthesized per day) were determined in female Atlantic salmon returning to the River Tay, Scotland in July and in October after a 95 day period without food, during which time the animals became sexually mature. During the 95 day period of starvation/sexual maturation the ventricle and red muscle remained as a constant proportion of fresh weight whereas the liver, gill and ovary increased and the stomach and white muscle decreased. Fractional rates of protein synthesis increased markedly in the liver, stomach and ovary during the period of starvation/sexual maturation. In the gill, ventricle and white muscle fractional protein synthesis rates increased slightly or remained constant. From the estimated rates of protein loss or gain in the various tissues it is concluded that there is considerable protein turnover and repartitioning of amino acids during the period of starvation and sexual maturation. The absolute rate of protein synthesis rates in the ovary indicates that this tissue made the largest contribution to the energy and amino acid demands of the fish, whilst most of the amino acids required for maturation of the ovary were derived from white muscle, principally as the result of increased muscle protein degradation.

Quantitative changes in yolk protein and other components in the ovary and testis of the sea urchin Pseudocentrotus depressus

“…In scallops, proteins are stored in the adductor muscle and then mobilized into the gonad for gametogenesis (Mathieu and Lubet, 1993). In salmonids, proteins stored in the white muscle are mobilized into the gonad to produce gametes (Mommsen et al, 1980;Martin et al, 1993). Muscle protein can be considered to serve as a protein reserve for gametogenesis in these animals.…”

Metabolic adaptations of oxidative muscle during spawning migration in the Atlantic salmon Salmo salar L.

“…The spawning migration of Atlantic salmon (Salmo salar L.) is known to be an energetically expensive stage in the life history of individual fish (Martin et al 1993;Jonsson et al 1997). Upon entering most rivers, migrating salmon are subjected to numerous environmental, biological, and anthropogenic perturbations.…”

Fructose 1,6 bisphosphatase activity in liver and gonads of sea bass (Dicentrarchus labrax). Influence of diet composition and stage of the reproductive cycle

“…Sex-related differences were found. The gonadosomatic index for females was significantly higher than for males during the spawning period, as obtained for sea bass (Barnab6 1980) and other fish species (Idler and Bitner 1960;Crupkin et al 1988;Martin et al 1993). Accordingly, some of these authors have proposed that ovary development involves a major energy cost, due mainly to vitellogenesis and egg production, which would also explain the mobilization of approximately 75% of visceral fat in female sea bass during the spawning season compared with about 50-60% in males.…”