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The mechanosensory lateral line system of fish is responsible for several functions such as balance, hearing, and orientation in water flow and is formed by neuromast receptor organs distributed on head, trunk and tail. Superficial and canal neuromasts can be distinguished for localization and morphological differences. Several information is present regarding the superficial neuromasts of zebrafish and other teleosts especially during larval and juvenile stages, while not as numerous data are so far available about the ultrastructural characteristics of the canal neuromasts in adult zebrafish. Therefore, the aim of this study was to investigate by transmission electron microscopy the ultrastructural aspects of cells present in the canal neuromasts. Besides the typical cellular aspects of the neuromast, different cellular types of hair cells were observed that could be identified as developing hair cells during the physiological turnover. The knowledge of the observed cellular types of the canal neuromasts and their origin could give a contribution to studies carried out on adult zebrafish used as model in neurological and non‐neurological damages, such as deafness and vestibular disorders.  相似文献   
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A total of 82 grapevine genotypes were sampled from several areas of the Italian region of Sicily where vineyards are widely spread. The grapevines were characterized using six microsatellite markers (VVS2, VVMD5, VVMD7, VVMD27, VrZAG62 and VrZAG79) to evaluate genetic diversity. Thirty-seven of the 82 cultivars sampled had their names quoted in historical and literary sources, while 45 cultivars from old vineyards did not have their names reported in ancient literature. According to their genetic profiles at SSR loci, 70 different cultivars were found, while interesting cases of synonymies (Regina and Moscato bianco, Alicante and Dolcetta or among different clones of Zibibbo and Catarratto) and cases of homonymy (Frappato and Nerello Mascalese) were discovered. Several genetic parameters were calculated to assess the efficacy of the loci chosen in this work. Pairwise genetic distances between all cultivars were calculated. A dendrogram representing the genetic similarities among cultivars was depicted using the UPGMA method to investigate their relationships, explaining them from a historical point of view. The cluster distribution of cultivars clearly does not reflect their current geographical distribution, suggesting successive introductions of cultivars in Sicily from different areas of origin.  相似文献   
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  • 1. Spatio‐temporal distribution and anthropogenic mortality factors were investigated in loggerhead turtles (Caretta caretta) found stranded or floating in the waters around Italy. A total of 5938 records for the period 1980–2008 were analysed concerning loggerhead turtles measuring from 3.8 to 97 cm curved carapace length (mean: 48.3 cm).
  • 2. Results highlighted the following conservation issues: (i) in the study area, anthropogenic mortality is higher than natural mortality; (ii) interaction with fisheries is by far the most important anthropogenic mortality factor; (iii) longlines are an important mortality factor in the southern areas; (iv) trawlers are the cause of high numbers of dead strandings in the north Adriatic; (v) entanglement in ghost‐gear or in other anthropogenic debris affects high numbers of turtles; and (vi) boat strikes are an important source of mortality in most areas but mostly in the warm seasons.
  • 3. Results also indicate that: (vii) the north Adriatic is the area with the highest turtle density; and (viii) the south Adriatic and to a lesser extent the surrounding areas of the north Adriatic and the Ionian, are important developmental areas for loggerhead turtles in the first years of life.
  • 4. Italy is in the centre of the Mediterranean Sea and borders major foraging areas for the loggerhead turtles in the region, and these results confirm previous concerns about the level of anthropogenic mortality in Italian waters. Copyright © 2010 John Wiley & Sons, Ltd.
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The Atlantic salmon (Salmo salar) is a freshwater and marine fish of the family Salmonidae, widely farmed in aquaculture facilities in several countries. The salmon are carnivorous, but in aquaculture, alternative foods have been experienced. It is well known that feeding in captivity should cause adaptation and modifications of the morphological characteristics of the oral cavity, especially of tongue; therefore, the aim of this study was to investigate, by light, laser confocal and scanning electron microscopy, the morphological characteristics of the tongue dorsal surface, considering the importance of the correlations between feeding habits and the anatomy of the tongue. Scanning electron microscopy demonstrates the presence of caniniform teeth with oro-aboral orientation surrounded by numerous filiform papillae, single, fused or arranged in row. Oro-aborally, the papillae show an appearance like a rosette and they disappear at level of the root. Light and laser confocal microscopy demonstrates that the mucosa is covered by a non-keratinized stratified pavement epithelium with, in the deepest layer, the presence of a triangular structure whose apex is cranially directed and base facing aborally. In this structure, spindle-shaped cells are present, with a vimentin immunoreactivity, that for their characteristics could be adult mesenchymal stem cells. The obtained data could be useful not only for further studies on the nutrition, but it is interesting the detection of tissues typical of the embryo-fetal phase in the adult specimens tongue, thus giving a basis for studies of potential applications, if any, regarding cell therapies for different clinical indications.  相似文献   
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The oral cavity in vertebrates plays a very important role in food intake mechanics and also contains chemical sensors for food and environmental water. Comparative studies revealed morphological and functional inter‐specific differences that can be correlated to evolutionary events and might represent the adaptation to environmental conditions present in different habitats (Iwasaki, 2002). Particularly these events are strictly dependent on the food intake mechanisms determining the success of the adaptation of vertebrates to their environment and therefore their survival (Roth and Wake, 1989). Since data about the morphology of the zebrafish oral cavity are scarce the aim of the present research was to study it by light, scanning and transmission electron microscopy and immunohistochemistry for some growth factor receptors, i.e. trkA and trkB. The zebrafish was chosen because as a vertebrate it has valuable features as a model for study of vertebrate development (Withfield, 2002). Adult zebrafishes were anesthesized with MS222 and the samples were taken and routinely processed for light and electron microscopy and for indirect peroxidase immunohistochemistry. The topographical and ultrastructural study demonstrated the presence of three different zones. The outer zone is characterized orally by the presence of a papilla and by an epithelium with numerous taste buds that are chemosensory endorgans consisting of modified epithelial cells. Their function is to sample potential food and selecting it according to its edibility (Hansen et al., 2002). Both in upper and lower intermediate zones, the presence of internal valves with a semi‐lunar shape was evident, probably able to regulate the mouth closure. The most internal lower zone corresponds to the tongue that in zebrafish is only a thickening of the pavement mucosa with a stratified epithelium. Immunohistochemistry demonstrated both in upper and lower zones the presence of numerous taste buds that were immunoreactive to TrkA and TrkB‐like neurotrophin receptors, confirming the role of these receptors in taste buds sensory cells (Germanà et al., 2004). The present results give a contribution to the morphological knowledge of the zebrafish oral cavity, an animal model commonly used for developmental studies of vertebrates.  相似文献   
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Leptin is an anorectic hormone secreted mainly by peripheral adipocytes but also by other central and peripheral tissues. It acts by means of a receptor called OB‐R, influencing not only appetite and body mass but being also involved in many fields like endocrinology, metabolism and reproduction. Immunohistochemistry and qRT‐PCR techniques were, respectively, used to demonstrate the presence of leptin and its receptor in the gut of adult zebrafish and to evaluate the leptin gene expression response to feeding and fasting. Immunoreactivity for the antibodies utilized was demonstrated in feeding but not in fasting fish, and the gene expression analysis corroborates the data obtained by immunohistochemistry. Therefore, all the obtained results support the hypothesis of the role of this hormone in food regulation in zebrafish.  相似文献   
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