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Öğe Cardiac toxicity of acrolein exposure in embryonic zebrafish (Danio rerio)(Springer Heidelberg, 2020) Arman, Sezgi; Isisag Ucuncu, SemaAcrolein is a widely distributed pollutant produced from various sources such as industrial waste, organic combustion, and power plant emissions. It is also intentionally released into irrigation canals to control invasive aquatic plants. Zebrafish (Danio rerio) has a good reputation for being an attractive model organism for developmental and toxicological research. in this study, zebrafish embryos were exposed to acrolein to investigate the cardiotoxic effects. the 96-h LC50 (median lethal concentration) value of acrolein was determined as 654.385 mu g/L. Then, the embryos were treated with the sublethal experimental concentrations of acrolein (1, 4, 16, 64, and 256 mu g/L) for 96 h. Embryos were examined at 48, 72, and 96 h post-fertilization (hpf). Acrolein affected the cardiac morphology and function of the embryos. Sinus venosus-bulbus arteriosus (SV-BA) distance of 64 mu g/L and 256 mu g/L acrolein groups was elongated compared with the control samples. Immunostaining with MF20 antibody clearly exhibited that the atrium positioned posterior to the ventricle which indicated cardiac looping inhibition. Histological preparations also showed the mispositioning and the lumens of the chambers narrowed. Acrolein-induced increased heart rate was noted in the 4, 16, 64, and 256 mu g/L treatment groups. Taken together, these results indicated that acrolein disrupted the heart development and cardiac function in zebrafish, suggesting that its water-borne risks should be considered seriously.Öğe Comparison of vertebrate skin structure at class level: A review(Wiley, 2022) Akat, Esra; Yenmis, Melodi; Pombal, Manuel A.; Molist, Pilar; Megias, Manuel; Arman, Sezgi; Vesely, MilanThe skin is a barrier between the internal and external environment of an organism. Depending on the species, it participates in multiple functions. The skin is the organ that holds the body together, covers and protects it, and provides communication with its environment. It is also the body's primary line of defense, especially for anamniotes. All vertebrates have multilayered skin composed of three main layers: the epidermis, the dermis, and the hypodermis. The vital mission of the integument in aquatic vertebrates is mucus secretion. Cornification began in apmhibians, improved in reptilians, and endured in avian and mammalian epidermis. The feather, the most ostentatious and functional structure of avian skin, evolved in the Mesozoic period. After the extinction of the dinosaurs, birds continued to diversify, followed by the enlargement, expansion, and diversification of mammals, which brings us to the most complicated skin organization of mammals with differing glands, cells, physiological pathways, and the evolution of hair. Throughout these radical changes, some features were preserved among classes such as basic dermal structure, pigment cell types, basic coloration genetics, and similar sensory features, which enable us to track the evolutionary path. The structural and physiological properties of the skin in all classes of vertebrates are presented. The purpose of this review is to go all the way back to the agnathans and follow the path step by step up to mammals to provide a comparative large and updated survey about vertebrate skin in terms of morphology, physiology, genetics, ecology, and immunology.Öğe Gonadal histology of the tiger barb Puntius tetrazona (Cyprinidae)(Bdfish, 2020) Arman, Sezgi; Ucuncu, Sema IsisagThe ornamental fish industry constitutes a big portion of the economy in many countries of the world. Thousands of attractive fish species are traded annually. The tiger barb Puntius tetrazona is one of the most charming freshwater aquarium species worldwide. The present paper aimed at expanding the knowledge of the reproductive biology of this tropical fish. The ovary and the testis tissues of the tiger barb were embedded in paraffin following routine histological processes, stained with hematoxylin and eosin and Mallory's trichrome techniques, and investigated by light microscopy. Histological examinations confirmed asynchronous-type ovaries resembling four different developmental stages including primary growth, cortical alveolar, vitellogenic and maturation. in the testis, primary spermatogonia, secondary spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa were identified. All oogenetic and spermatogenetic phases and mature germ cells occurred simultaneously in the tiger barb. This feature allows this tropical fish to breed rapidly and helps expanding its global trades.Öğe Histochemical Characterization of Convict Cichlid (Amatitlania nigrofasciata) Intestinal Goblet Cells(Zoological Soc Pakistan, 2017) Arman, Sezgi; Ucuncu, Sema IsisagIn the present study, some histochemical features of goblet cells of the intestine of convict cichlid (A. nigrofasciata) were described. In order to reveal the main histological construction, transverse sections of different parts of intestine were firstly stained with hematoxylin eosin (H-E). Sections of anterior, mid and posterior intestinal segments were also treated with different staining methods of alcian blue (AB) at pH 2.5, aldehyde fuchsin (AF), periodic acid-Schiff (PAS), KOH/PAS and PAS/AB (pH 2.5) and investigated. Goblet cells of anterior intestine were colored strongly by AB (pH 2.5), AF and PAS; and moderately by PAS/AB (pH 2.5) (AB dominant). In the mid part of the gastrointestinal tract, goblet cells were also stained strongly with AB, PAS and PAS/AB (pH 2.5) (AB dominant), however, their reactions to KOH/PAS treatment were recorded as negative. Because of numerous supranuclear vacuoles of the epithelial cells, only a few goblet cells could be differentiated in posterior parts of alimentary channel, with their weakly reaction to AB (pH 2.5), PAS and PAS/AB (pH 2.5). Moreover, these cells were not stained with AF and KOH/PAS. According to their affinities, goblet cells oriented in anterior and the mid intestine were mainly classified as acidic (AB-positive) and neutral (PAS-positive). Statistical analysis were confirmed that, the numbers of acidic and neutral cells of per unite square of epithelial area were significantly different.Öğe Histopathological Effects of Fonofos on Gills of Zebrafish (Danio rerio)(2019) Arman, Sezgi; Üçüncü, Sema İşisağOrganophosphate pesticides are commonly used to increase agricultural efficiency worldwide. However, it has been proved that these chemicals generally do not show target specificity and non-target vertebrate organisms are adversely affected by pesticide exposure. the aim of the present study was to examine the potential harmful effects of fonofos, an organophosphate insecticide, on the gill tissues of zebrafish (Danio rerio). Adult zebrafish were exposed to 1, 2 and 4 mg/L fonofos for 96 hours. Gill tissues were removed, fixed with Bouin’s fluid and embedded in paraffin. 5 ?m serial sections were stained with hematoxylin-eosin, Gomori trichrome or periodic acid-Schiff. Samples were investigated by light microscopy and histological alterations were compared with the 0.1% dimethyl sulfoxide (DMSO) exposed solvent control samples. Fonofos caused epithelial lifting, curling of secondary lamellae, desquamation, epithelial hyperplasia, and lamellar fusion in the gills. Gills showed distinct histopathological changes through fonofos exposure. It was determined that fonofos is a threat to non-target organisms living in aquatic ecosystems.Öğe İki farklı pestisit (acrolein ve fonofos) maruziyetinin zebra balığında (Danio rerio) kalp gelişimi üzerindeki etkileri(Ege Üniversitesi, Fen Bilimleri Enstitüsü, 2018) Arman, Sezgi; İşisağ Üçüncü, SemaZebra balığı (Danio rerio), gelişim ve toksikoloji araştırmalarında kullanılan ilgi çekici bir model organizma olmasıyla tanınır. Bu çalışmada, kardiyotoksik etkilerini incelemek üzere zebra balığı embriyoları acrolein (herbisit) ve fonofosa (insektisit) maruz bırakıldı. Gelişimsel toksisite de ayrıca değerlendirildi. Acrolein ve fonofosun 96 saatlik LC50 değerleri sırasıyla 654,385 µg/L ve 7,067 mg/L olarak belirlendi. Daha sonra embriyolara 96 saat boyunca 1, 4, 16, 64, 256 µg/L acrolein ve 0,25, 0,5, 1, 2, 4 mg/L fonofos uygulandı. Embriyolar 48, 72 ve 96. saatlerde incelendi. İki pestisitin de embriyoların gelişimi ile kalbin morfolojisi ve işlevini önemli ölçüde etkilediği gözlendi. Sinüs venozus-bulbus arteriyozus (SV-BA) mesafesinin 64, 256 µg/L acrolein ve 2, 4 mg/L fonofos uygulanan gruplarda kontrollere kıyasla daha uzun olduğu kaydedildi. MF20 antikoru ile immünoboyama, atriyumun açıkça ventrikülün arkasında konumlanmış, yani kalp tüpünde normal kıvrılmanın engellenmiş olduğunu gösterdi. Ayrıca kalp duvarının histolojik yapısında da değişimler belirlendi. 4, 16, 64 ve 256 µg/L uygulamalarında acrolein indüklü artan kalp atım hızı gözlenirken, fonofos yalnızca 4 mg/L'de kalp atım sayısının azalmasına yol açtı. Zebra balığının gelişmekte olan kalbinin acrolein ve fonofos için bir hedef organ olduğu ortaya kondu ve etki mekanizmaları üzerinde daha ileri araştırmalar yapılması gerektiği sonucuna varıldı.Öğe Impact of acute fonofos exposure on skeletal muscle of zebrafish: Histopathological and biometric analyses(Edp Sciences S A, 2021) Arman, Sezgi; Ucuncu, Sema IsisagIt is widely known that pesticides generally do not show target specificity, and off-target species are strikingly affected by these chemicals. In the current work, histological changes in skeletal muscles of zebrafish (Danio rerio) caused by fonofos, an acetylcholinesterase (AChE) inhibitor organophosphate insecticide, were examined. Zebrafish were treated with 1 mg/L, 2 mg/L and 4 mg/L of fonofos for 96 hours. Skeletal muscle samples were removed from the pectoral region and embedded in paraffin. Sections were stained with Mayer's Hematoxylin and Eosin, Gomori's Trichrome and Periodic Acid Schiff techniques. Histopathological alterations were investigated by light microscopy. Fibrosis, intramyofibrillar vacuoles, disintegrated myofibrils, splitting of myofibers, atrophic and disappeared fibers, histoarchitectural loss, necrosis and progressive decrement in glycogen content were noted. Muscle fiber diameter measurements were also performed. Statistical analysis showed that measured fiber diameters of all fonofos exposed groups were significantly different from the control group, and they decreased in a concentration-dependent manner. These results suggested that fonofos caused significant myoarchitectural impairments in non-target freshwater zebrafish. The present work investigated histological changes in skeletal muscles of zebrafish (Danio rerio) caused by fonofos, an organophosphate insecticide. Fonofos-induced fibrosis, intramyofibrillar vacuoles, disintegrated myofibrils, splitting of myofibers, atrophic and disappeared fibers, histoarchitectural loss, necrosis and progressive decrement in glycogen content were noted. Muscle fiber diameter measurements showed that the fiber diameters of all fonofos exposed groups were decreased in a concentration-dependent manner. These results suggested that fonofos caused significant myoarchitectural impairments in non-target freshwater zebrafish.
