Histological and biochemical evaluation of skeletal muscle in the two salmonid species Coregonus maraena and Oncorhynchus mykiss

Abstract

The growth of fishes and their metabolism is highly variable in fish species and is an indicator for fish fitness. Therefore, somatic growth, as a main biological process, is ecologically and economically significant. The growth differences of two closely related salmonids, rainbow trout (Oncorhynchus mykiss) and maraena whitefsh (Coregonus maraena), have not been adequately studied as a comparative study and are therefore insufficiently understood. For this reason, our aim was to examine muscle growth in more detail and provide a first complex insight into the growth and muscle metabolism of these two fish species at slaughter size. In addition to skeletal muscle composition (including nuclear counting and staining of stem and progenitor cells), biochemical characteristics, and enzyme activity (creatine kinase, lactate dehydrogenase, isocitrate dehydrogenase) of rainbow trout and maraena whitefish were determined. Our results indicate that red muscle contains cells with a smaller diameter compared to white muscle and those fibres had more stem and progenitor cells as a proportion of total nuclei. Interestingly, numerous interspecies differences were identified; in rainbow trout muscle RNA content, intermediate fibres and fibre diameter and in whitefish red muscle cross-sectional area, creatine kinase activity were higher compared to the other species at slaughter weight. The proportional reduction in red muscle area, accompanied by an increase in DNA content and a lower activity of creatine kinase, exhibited a higher degree of hypertrophic growth in rainbow trout compared to maraena whitefish, which makes this species particularly successful as an aquaculture species.

Muscle Fiber Characteristics and Transcriptome Analysis in Slow- and Fast-Growing Megalobrama amblycephala

“…In 20-month-old common carp, the hypertrophy of muscle fibers was an important reason for the difference in growth [4]. Compared with two-year-old Coregonus maraena, the hypertrophy of muscle fibers is an important reason for the rapid growth of one-year-old Oncorhynchus mykiss [19]. These results indicate that hypertrophic growth of muscle plays an important role in the growth of skeletal muscle in the later development stage in many species, and the role of hyperplasia and hypertrophy in muscle growth depends on the developmental stage and species.…”

Starvation Affects the Muscular Morphology, Antioxidant Enzyme Activity, Expression of Lipid Metabolism-Related Genes, and Transcriptomic Profile of Javelin Goby (Synechogobius hasta)

“…To date, research on starvation-induced oxidative stress in fish has mainly focused on the liver and gastrointestinal tract rather than muscle tissue despite the fact that muscle accounts for the overwhelming majority of the fish mass [ 8 ]. Moreover, muscle tissues play a crucial role in the metabolic homeostasis of fish [ 29 , 36 ]. The significant elevation of muscle SOD in the 7-day fasted group appeared to neutralize starvation-induced intramuscular ROS to some extent.…”

“…These responses of lpl and cpt1a to starvation suggested that the biological processes involved in lipid hydrolysis and fatty acid β -oxidation were suppressed in S. hasta muscle. Unlike S. hasta liver, which can store large amounts of fat under natural conditions [ 18 ], white muscle may preferentially consume glycogen deposits to meet energy requirements in situations of nutrient unavailability [ 6 , 36 ], resulting in an increase in anaerobic glycolysis until muscle glucose is fully depleted due to prolonged starvation. The anaerobic environment of glycolysis might repress the oxidative metabolism of the limited lipid storage in white muscle fibers [ 52 ].…”

Establishment of an in vitro model from the vulnerable fish species Coregonus maraena (maraena whitefish): Optimization of growth conditions and characterization of the cell line

“…Dorsal fin from an adult C. maraena was used for cell isolation. The fish was obtained from the Institute of Fisheries of the State Research Center for Agriculture and Fishery Mecklenburg-Vorpommern in Born within another project (Grunow, Stange et al, 2021). Before cell isolation, the fin tissue was washed intensively three times in 1x DPBS (Dulbecco's Phosphate-Buffered Saline; PAN-Biotech).…”