Teresa Ostaszewska

The effects of CEME and it complex with GO injected in ovo on the growth and development of chicken embryo hindlimb muscle were investigated. First, the preliminary in vitro study on primary muscle precursor cell culture obtained from a nine-day-old chicken embryo was performed to assess toxicity (MTT assay) of CEME, GO (100 ppm) and it complex with different concentrations (1, 2, 5, and 10 wt.%). The effect on cell proliferation was investigated by BrdU assay. CEME at concentrations 1–5% increased cell proliferation, but not the complex with GO. In vitro cytotoxicity was highest in 10% and GO groups. Next, the main experiment with chicken embryos was performed with CEME, GO and it complex injected in ovo on day one of embryogenesis. On day 20 of embryogenesis survival, morphological development, histological structure of the muscle, and biochemical parameters of blood serum of the embryos were measured. No negative effect on mortality, body weight, or biochemistry of blood after use of CEME or GO-CEME complexes was observed. Interestingly, the slight toxicity of GO, observed in in vitro studies, was not observed in vivo. The use of CEME at the levels of 2% and 5% improved the structure of the lower limb muscle by increasing the number of cells, and the administration of 2% CEME increased the number of nuclei visible in the stained cross-section of the muscle. The complex GO-CEME did not further improve the muscle structure. The results indicate that CEME can be applied as an in ovo enhancer of muscle development in broilers.

The study is a preface to redesign farming of carp, and the aim was to determine the influence of three artificial feeds on carp growth performance, chemical composition, intestinal and liver histology, and the expression of two main genes of fatty acid catabolism: acyl-coenzyme A oxidase 1 (acox1) and peroxisome proliferator-activated receptor  (ppar). The 61-days trials were run in set of 9 floating cages in triplicate (n=3 per diet). The results showed that zootechnical parameters (i.e. feed conversion ratio, protein efficiency ratio) significantly improved with increased level of fat in diet, for instance, the lowest FCR was noted for fish fed diet A (9.900.23% of fat). Additionally, gene expression analysis revealed that activity of acox1 and ppar in the liver depend on the fat level in carp diet. The expression of ppar and its target gene acox1 in the intestine of fish showed a distinct pattern in relation to liver samples, since feeds with high and low levels of fat exerted a comparable effect on the mRNA level of the studied genes. In conclusion, this study showed that the level of fat in common carp diets correlated with the level of lipids in the meat.

Nutrition affects the metabolism of muscle cells and myogenic progenitor cells which play a crucial role in the growth and development of the muscle tissue. Because of the fact that the development process of yellow perch muscle tissue is not well known, the study aimed to analyze the influence of diets containing wheat gluten and supplemented with Lys and Gly in dipeptides or free form. Fish were allocated into 12 tanks and divided into four groups. Two of the experimental diets were supplemented Lys-Gly in the dipeptide form (DP group) or free amino acids (FAA group). The third was not supplemented with lysine (LF group). The fourth group of fish was fed commercial starter Bio-Oregon (C group). Histological or histomorphometric analyses were conducted: white muscle area, the total number of muscle fibers, the total number of white muscle nuclei, muscle fiber area, number of proliferating myonuclei. Fish fed LF diet showed the lowest number of nuclei and satellite cells proliferation. Results in DP and FAA groups were similar to that observed in fish fed C diet. Summarizing, wheat gluten-based diets supplemented with Lys-Gly dipeptide or free Lys and Gly amino acids exert beneficial effects on the morphology of yellow perch white muscle.

The butterfly splitfin (Ameca splendens) is a fish species that belongs to the Goodeidae family. The biology of this species, which is today at risk of extinction in its natural habitats, has not been fully explored. The objective of the present study was to characterize melanomacrophages (MMs) and the melanomacrophage centers (MMCs) that they form, associated with the immunological system of butterfly splitfin. Butterfly splitfin is a potential new model species with a placenta for scientific research. In addition, knowledge about the location and characteristics of MMCs will allow the effective development of a conservation strategy for this species and monitoring of the natural environment. The results of histological analyses show that the immune system of fish aged 1 dph was completely developed. Single MMs were observed in hepatic sinusoids and in head kidney and their agglomerations were noticed in the exocrine pancreas and in the spleen. Hemosiderin was detected in single MMs in the head kidney of fish aged 1 dph, and in the spleen, exocrine pancreas and liver of older fish. Furthermore, histological analyses of older fish revealed the presence of lipofuscin in the head kidney, exocrine pancreas and spleen in melanomacrophages. The localization and size of MMCs may be an indicator of the health status of fish and may be a biomarker of their immune system activation. The obtained results will allow effective monitoring of the populations of this species. Furthermore our results demonstrate the contribution of liver in the iron homeostasis in fish, as evidenced by enhanced deposition of hemosiderin during butterfly splitfin ontogenesis.

Nanoparticles are commonly used in the industry and are present in consumer goods; therefore, evaluation of their potential toxicity is necessary. The aim of the present study was to assess the cytotoxic effects of the nanoparticles of silver (AgNPs) at the concentration of 1.5 mg L⁻¹ and copper (CuNPs) at 0.15 mg L⁻¹ on rainbow trout (Oncorhynchus mykiss) hepatocytes after 28 days of exposure. Histological analysis revealed dilated sinusoids, shrunken hepatocytes, nuclear necrosis, and increased number of Kupffer cells in the liver of fish exposed to nanoparticles. The lowest hepatocyte proliferation index was observed in fish treated with AgNPs. Ultrastructural studies revealed mitochondrial edema and cristolysis, dilated and loosened endoplasmic reticulum, cytoplasm vacuolation, accumulation of lipid droplets, glycogen depletion, and formation of myelin-like bodies. The results also revealed that the liver of fish exposed to copper nanoparticles showed higher regenerative potential indicated by higher proliferation index, more abundant glycogen, and more numerous Kupffer cells compared to the fish treated with silver nanoparticles.