Teresa Ostaszewska

The effect of plant protein-based diet supplemented with dipeptide or free amino acids on digestive tract morphology and PepT1 and PepT2 expressions in common carp (Cyprinus carpio L.).

Common carp (Cyprinus carpio) of average body mass 0.07+/-0.02 g were fed three formulated diets: wheat gluten protein-based diet supplemented with Lys-Gly dipeptide (PP), wheat gluten protein-based diet supplemented with free lysine and glycine (AA), and a wheat gluten protein-based control diet without lysine supplementation (CON), frozen zooplankton (Z) (restricted diet), and a commercial starter food Aglo Norse (AN). After 4 weeks of experimental feeding, fish fed AN diet showed the highest body mass and length. Significantly lower mass occurred in groups fed PP, AA, CON, and Z. Fish fed CON diet showed the lowest intestinal folds and the highest number of mucous cells. Fish fed PP diet showed a significantly higher number of gastrin/cholecystokinin (CCK) positive cells. The diameter of lipid vacuoles in hepatocyte cytoplasm of fish fed formulated diets (PP, AA and CON) was significantly higher than in fish fed zooplankton (Z) and the commercial diet (AN). Hepatocytes of fish fed AA and CON showed a higher nucleus proliferation rate than in the other experimental groups. The quantitative analysis of the number of proliferating cell nuclear antigen (PCNA) and caspase-3(rabbit polyclonal antibody CPP-32)-positive cells showed that the highest proliferation rate was accompanied by the high apoptosis in the intestine of fish fed AA and CON. After 4 weeks of experimental feeding the highest relative expression of PepT1 gene was observed in fish fed PP diet, while the lowest expression occurred in fish fed CON. Feeding carp plant protein-based diet supplemented with Lys-Gly dipeptide (PP) had a beneficial influence on fish growth and metabolism in the digestive tract as compared to fish fed control diet without lysine supplementation (CON).

The effect of peptide absorption on PepT1 gene expression and digestive system hormones in rainbow trout (Oncorhynchus mykiss).

The present study evaluates the effect of protein source (dipeptides, free amino acids, and intact protein) on development and growth of Salmonid fish alevin. Specifically, we follow the expression of oligopeptide transporter protein PepT1 in the intestine of rainbow trout (Oncorhynchus mykiss). Fish were fed exogenously one of four diets: three formulated (lysyl-glycine dipeptide supplemented diet - PP, free lysine and glycine supplemented diet - AA, control diet with no lysine - CON) or commercial starter (Aller Futura - AF). Fish increased mean body weight 8 fold with PP- and AA-supplemented diets resulting in significantly higher weight gain than fish fed CON. Statistical analysis revealed a significant increase in relative PepT1 expression of fish fed experimental diets. Immunohistochemical staining with PepT1 antibody showed the presence of the transporter protein in the brush border membrane of the proximal intestinal enterocytes of fish from all experimental groups. Leptin immunoreactivity occurred not only in the gastric glands but also in proximal intestine and pyloric caeca of fish fed PP, AA and AF diets. Leptin immunoreactivity was also observed in hepatocyte cytoplasm and pancreatic acinar cells. Gastrin/CCK immunoreactive cells were present in the proximal intestine and pyloric caeca.

Influence of nanoparticles of platinum on chicken embryo development and brain morphology

Platinum nanoparticles (NP-Pt) are noble metal nanoparticles with unique physiochemical properties that have recently elicited much interest in medical research. However, we still know little about their toxicity and influence on general health. We investigated effects of NP-Pt on the growth and development of the chicken embryo model with emphasis on brain tissue micro- and ultrastructure. The embryos were administered solutions of NP-Pt injected in ovo at concentrations from 1 to 20 μg/ml. The results demonstrate that NP-Pt did not affect the growth and development of the embryos; however, they induced apoptosis and decreased the number of proliferating cells in the brain tissue. These preliminary results indicate that properties of NP-Pt might be utilized in brain cancer therapy, but potential toxic side effects must be elucidated in extensive follow-up research.

Intersex Gonad Differentiation in Cultured Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) Sturgeon

ABSTRACT Among sturgeons, the occurrence of individuals with gonads containing both testis and ovary components is considered pathological, and such fish are described as intersex individuals or intersexes. Intersexes are observed in both wild and cultured populations of sturgeon, usually at low frequencies. In the present study, intersex Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeons constituted 30% of the studied populations. Macroscopically, intersex gonads were recognizable from 500 days posthatching (dph). Initially, gonads with predominantly male characteristics (testis-ova) were observed, but in older fish gonads with predominantly female traits (ova-testis) were more frequent. Using microscopic analysis, intersex gonads were discernible by 130–200 dph. Observations of intersex germinal epithelium development and analysis of sex distribution in the study populations indicated that feminization was occurring. Histological analysis revealed that differentiation of the germinal epithelium in such gonads was accompanied by various morphological alterations (transformations) that were described using quantitative and localization criteria. The most common type of transformations, massive subepithelial transformations, was manifested by the presence of abundant female germinal tissue located under the gonad surface epithelium in the developing testis. These transformations were identified in the early development stage (100–200 dph). In this type of transformation, differentiation of female germinal tissue at the gonad surface and male tissue at the mesorchium/mesovarium resulted in complete formation of both male and female germinal epithelia within the same gonad.

Cloning two PepT1 cDNA fragments of common carp, Cyprinus carpio (Actinopterygii: Cypriniformes: Cyprinidae).

1 Division of Ichthyobiology and Fisheries, Faculty of Animal Science, Warsaw University of Life Sciences, Warsaw, Poland 2 Division of Molecular Cytogenetics, Faculty of Biotechnology and Animal Science, West Pomeranian University of Technology, Szczecin, Poland 3 Laboratory of General Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, via Provinciale LecceMonteroni, Lecce, Italy 4 School of Environment and Natural Resources, Ohio State University, Columbus, Ohio, USA

Development and Functionality of the Digestive System in Percid Fishes Early Life Stages

In percid fishes, the development of digestive structures and activities is quite similar to that of other carnivorous species (sea bass and sea bream). In most species at hatching, the digestive tract is a simple tube consisting of undifferentiated cells. The mouth and anus are closed and the esophagus is not connected with the intestine. Liver and pancreas are undifferentiated. Digestive enzymatic activities (pancreas, intestine) are detected shortly after hatching. According to histological and enzymatic studies, important changes occur around mouth opening (fifth to seventh dph). The pancreas shows exocrine activity and the liver becomes functional with adipogenic and glycogenic functions. The primary stomach develops in pikeperch and even earlier in Eurasian perch. Pancreatic (trypsin, amylase) and intestinal (leucine-alanine peptidase, Alkaline phosphatase, aminopeptidase N) enzyme activities increase at mouth opening. Leucine-alanine peptidase (cytosolic enzyme) activity declines after mouth opening concurrently with the strong increase of the brush border membrane enzymes (Alkaline phosphatase, leucine-aminopeptidase N) activity indicating the development of the brush border membrane of intestinal enterocytes. The stomach development occurs between 15th and 20th dph in pikeperch and between 21th and 35th in Eurasian perch. Pepsin activity is detected only on day 29 in pikeperch as well as in Eurasian perch larvae and is concurrent with the development of gastric glands. The development of brush border membrane of the intestinal enterocytes and the gastric activity indicate that larvae acquire an adult mode of digestion. The digestive structures and activities can be affected by the nature and the diet composition. This aspect is also discussed in this chapter allowing an approach of the nutritional requirements of percid larvae.

Expression of dmrt1 and vtg genes during gonad formation, differentiation and early maturation in cultured Russian sturgeon Acipenser gueldenstaedtii

Expression of the dmrt1 and vtg genes was described using the real-time PCR (rt-PCR) method from 25 to 1600 days post-hatch (dph) in cultured Russian sturgeon Acipenser gueldenstaedtii. The level of dmrt1 transcription in gonads in subsequent studied periods increased exponentially while vtg expression increased in gonads and livers of A. gueldenstaedtii examined, but in later stages of development. Both dmrt1 and vtg genes showed elevated expression in intersex individuals probably caused by dietary exposure to phyto-oestrogens.

Development of the Sense Organs in Percid Fishes

Morphology and arrangement of various receptors in Teleostei indicate trophic and environmental preferences of different species. In the Percidae family, the sensory system begins to develop during embryogenesis and evolves over the larval and juvenile stages. The olfactory placodes develop between 26 (Gymnocephalus sp.) and 78 (walleye, Sander vitreus) hours post fertilization (hpf). However, the olfactory epithelium becomes fully developed at the age of about 1 month, as in the pikeperch (Sander lucioperca). During the ontogeny of fish, taste buds develop later than the olfactory system. In pike-perch juveniles, the first taste buds appear 13 days post hatching, primarily in the mouth and the gills, but later on they become visible in other parts of the body. During embryonic development of percids, the eye is the first sense organ to form. Gymnocephalus sp. show well developed eyes already after 26 hpf, while in walleye embryos the optic vesicles are fully formed after 70 hpf. Fish maintain body balance thanks to their inner ear (labyrinth), while the movement and vibration in the surrounding water is detected by canal neuromasts of the lateral line and superficial neuromasts of the skin. In the embryos of different percid species auditory vesicles appear after 26–70 h of development, while the lateral line – after 103 h.

Growth, Survival, and Body Composition of Sunshine Bass after a Feeding and Fasting Experiment

Abstract There is continuous interest in experimental, semipurified diet formulations and in the formulation of practical, inexpensive diets for grow out of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis). The effects of four diets on growth, survival, and body composition of sunshine bass after a feeding period (51 d) and a subsequent fasting period (14 d) were examined. To our knowledge, no previous sunshine bass feeding experiments have incorporated a fasting period to simulate the handling and acclimation conditions experienced by farmed fish that are stocked into new environments. Diets consisted of a high-nutrient commercial diet, a wheat-gluten-based practical diet, a semipurified diet (meeting standard nutrient requirements), and a frozen natural diet (chironomids). Fish were hand fed three times per day at 4% of body weight. At the end of the fasting period, samples were collected for histological analysis of the liver and posterior intestine. Survival was signi...