1,720,964 research outputs found
Identificazione intra-e inter specifica nelle famiglie Gadidae e Merluccidae (Gadiformi, Gadoidei)
No full textBiological Pollution: Molecular Identification of Non-Native Species in the Central Tyrrhenian Sea
No full textIn the Mediterranean, numerous and frequent bio-invasions by non-native species have occurred in recent decades. Among the reasons for this biological pollution there is the recent trend of global warming, which led to the extension of distribution area of tropical and/or thermophilic species. The present investigation describes analyses of 12S and 16S mt-rRNA gene fragments conducted on fresh muscle tissues of Tyrrhenian Sea fishes that confirm the morphological records of Fistularia commersonii, Sphoeroides pachygaster and Trachipterus trachipterus and provides a 12S mt-rRNA fragments database for future investigations on Remora osteochir, Tetragonurus cuvieri, Pomadasys incisus and Sudis hyalina. Among the species examined, Fistularia commersonii and Sphoeroides pachygaster are allochthonous species penetrated into the Mediterranean through Suez Canal (Red Sea) and Gibraltar Strait respectively. Pomadasys incisus is thermophilus species basically restricted to the southern parts of the Mediterranean. The others, Sudis hyalina, Tetragonurus cuvieri, Trachipterus trachipterus, and Remora osteochir are all autochthonous species of sporadic occurrence. Accordingly, the present work proposes the unequivocal non-native species discrimination by polymerase chain reaction that may be used as an index of biological pollution
MOLECULAR IDENTIFICATION OF RARE AND THERMOPHILIC FISH SPECIES IN THE CENTRAL TYRRHENIAN SEA
No full textIdentification of gadoid species (Pisces, Gadidae) by sequencing and PCR-RFLP analysis of mitochondrial 12S and 16S rRNA gene fragments.
No full textWe applied PCR–RFLP (PolymeraseChainReaction – Restriction Fragment Length Polymorphism) analysis to identify seven gadoid species of different biogeographical origin and commercial relevance, namely Gadus morhua (Atlantic ocean); Trisopterus minutus capelanus, Trisopterus minutus minutus, Molva elongata, Phycis blennoides, Micromesistius poutassou (Atlantic ocean and Mediterranean sea); Theragra chalcogramma (Pacific ocean). Two DNA fragments belonging to mitochondrial 12S and 16S rRNA genes of about 430 and 630 bp, respectively, were isolated by PCR amplification. Their direct sequencing showed a significant genotypic diversity among gadoid species, useful for species identification. Digestion of 16S rRNA gene PCR fragment with MvaI or Bsh1285I restriction enzymes, followed by agarose gel electrophoresis of the cleaved products, yielded specific restriction profiles that enabled direct, visual identification of the species analyzed. This PCR– RFLP method allowed a clear and rapid discrimination of the gadoid species studied
High-performance liquid chromatographic evaluation of vitamin E antioxidant resource in the european eel, Anguilla anguilla
No full textFish plays an important role in human diet and numerous changes occur in post-mortem affecting its chemical composition, nutritional contribution and fi llet quality. High performance liquid chromatographic (HPLC) method was carried out to quantify the Vitamin E (-tocopherol) resource in fresh European eel, Anguilla anguilla and to detect the antioxidant variation after storage for 24hrs and 48hrs at 4°C and frying, traditional Mediterranean cooking. Our results show a great resource of vitamin E in Anguilla anguilla fi llet. Storage and cooking effects depends by the initial vitamin E content and by the culinary way used
PCR-RFLP ANALYSIS OF MITOCHONDRIAL 16S rRNASEQUENCES OF GADIDAE AND MERLUCCIDAE(GADIFORMES, GADOIDEI) SPECIES
No full textOxidative defenses in the sea bass, Dicentrarchus labrax
No full textA study on the oxidative defenses during larval growth and under stress conditions was carried out in the bred sea bass, Dicentrarchus labrax. A high-pressure liquid chromatography (HPLC) method was used for the quantitative determination of vitamins C and E; glutathione peroxidase activity was measured by an enzymatic assay. Vitamin E was measured in the seminal fluid, eggs, embryos and larvae. Vitamins C and E, and glutathione peroxidase activity were measured in adults of Dicentrarchus labrax under normal conditions and subjected to hypoxia. Vitamin E content was high in seminal fluid, eggs, and embryos and at the early stage of larval development. It decreased slowly, but steadily, throughout the larval growth. In adults exposed to hypoxia, vitamins C and E levels were significantly lower with respect to the control group. Glutathione peroxidase levels showed a decrease in the hypoxia-subjected group, although the values were not significant
Selenoproteins and Fish Egg Quality
No full textThis work analysed the selenoprotein glutathione peroxidase (GPx) activity in eggs of Sparus aurata. GPx was found in eggs before and after fertilization, in embryos during development, at hatching and during larval development. The content was very low in segmentation and organogenesis whereas increased at the end of embryogenesis and in larval development. This study provides evidence on how selenoproteins as GPx exert an antioxidant defense in sea bass development and sustain antioxidants as quality index
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