111 research outputs found

    Spermatogenesis and sperm structure in the black-striped pipefish <i>Syngnathus abaster</i> (Teleostei, Syngnathidae) = Spermatogenesi e struttura degli spermatozoi in <i>Syngnathus abaster</i> (Teleostei, Synghathidae)

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    The gonads of adult males of the black-striped pipejish Syngnathus abaster were observed during the reproductive season to describe mature sperm both quantitativel/y and qualitatively. The results show that: a) the sperms number is always very low and, does not vary significantly during the reproductive season; b) all mature sperms observed may be assigned to the introsperm-like type. These data suggest that the unique and functional sperm of Syngnathids pertain to the introsperm type typical of internally fertilizing teleostean bony fishes

    First insights on the mitochondrial genetic variability of Lightiella magdalenina (Crustacea), the sole Mediterranean cephalocarid species

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    Background: Here we report the first insight into the mitochondrial (Cytochrome c Oxidase subunit I - COI and Cytochrome b - Cyt b) genetic variation of the only Mediterranean cephalocarid Lightiella magdalenina. Findings: COI sequences provide a scenario of low intraspecific variability, while significant genetic divergence occurs between L. magdalenina and L. incisa. Interestingly, Cyt b sequences reveal a higher degree of intraspecific variability, with no shared haplotypes between the sites considered. Conclusions: In the future, COI and Cyt b molecular markers could be used as valuable tools to shed new light into the extant species within the genus Lightiella thus providing molecular support to the taxonomical identifications carried out on a morphological basis

    Study of animal remains dug out during the excavations of a Nuragic village in Sardinia

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    This paper presents the results of the zooarchaeological analysis of the faunal materials brought to light during the excavations set up in the Nuragic village surrounding the Santu Antine Nuraghe, near Torralba (Sassari), Sardinia. Precisely, the remains come from the structure of the village named by archaeologists hut 12. They are 779 specimens out of thousands animal remains from the whole archaeological site. The majority of the rests belong to sheep (Ovis aries) or goats (Capra hircus), cattle (Bos taurus), pigs (Sus scrofa) and deers (Cervus elaphus). Such material may provide suggestions about the productive use of animals in the village and point out the importance of the economical management of animals in the Nuragic society. Indeed, many remains show signs with human origin, which testify that the hut may have been a workplace where bone fragments were processed to obtain different kind of tools

    Anatomical study of animal remains from Phoenician-Punic amphorae found in the Santa Giusta Pond, Sardinia (Italy)

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    During the underwater excavations carried out in the Santa Giusta Pond, near Oristano, Sardinia, a significant amount of Phoenician- Punic materials was brought to light including amphorae (dating back to 7th-2nd century BC) and vegetal and animal remains. All of these archaeological finds may come from Othoca, an important Phoenician- Punic city on the eastern shore of the pond, geographically corresponding with the modern-day town of Santa Giusta. Animal materials consist of more than 3000 very well-preserved remains, belonging to sheep (Ovis aries), goat (Capra hircus) and cattle (Bos taurus). Bone analyses allowed reconstructing the slaughtering methods, as well as manipulation procedures carried out to preserve meat in order to be exported overseas. Although pig (Sus scrofa) played an important economical role in other Sardinian Phoenician-Punic settlements, in this archaeological context this species is absent, suggesting that the meat contained in the amphorae was probably destined to other areas of the Mediterranean basin, where people did not eat pork

    Reproductive system of <i>Lightiella magdalenina</i> (Crustacea, Cephalocarida) = Apparato riproduttore in <i>Lightiella magdalenina</i> (Crustacea, Chefalocarida)

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    The aim of this study was to describe the morphology of the reproductive system of Lightiella magdalenina the only cefalocarid species known from Europe. Two adult specimens and one larval stage of L. magdalenina were analysed with light microscope and findings compared with available data from H. macracantha

    Autophagic processes increase during senescence in cultured sheep neurons and astrocytes

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    A possible response to aging is autophagy, a self-digestion process in which portions of cytoplasm are encapsulated by double-membrane-bound structures and delivered to lysosome for degradation. A previous work of our group showed that astrocytes under starving conditions are characterized by a higher upregulation of the marker of autophagy LC3 II than neurons. Aim of the present work was to evaluate LC3 II expression in an aging model consisting in fetal sheep neurons and astrocytes at 10, 20 and 30 days of culture. Such model has been validated by a remarkable activity of β-galactosidase, commonly used to reveal cell aging. LC3 II immunoreactivity in neurons and astrocytes progressively increased with time but differences were observed on the basis of cell density. Indeed, LC3 II immunoreactivity is higher in clusters of neurons and astrocytes and this may be due to the fact that cell-cell contact would represent a second stress in addition to aging itself. Both cell types displayed a reduction in LC3 II signal in nuclei, and a corresponding strengthening in the cytoplasm with time. This may be due to the need of aged cells to remove damaged cytoplasmic components through autophagic processes. Such variation in LC3 II localization could be caused by migration from the nucleus to cytoplasm as well as possible de novo intracytoplasmic production. The present work based on sheep neural cells in vitro may represent a helpful tool in the studies on aging processes in which autophagy plays a remarkable role

    Intra- and intermale variability of mature sperm traits analysed in two brackish water populations of the pipefish Syngnathus abaster (Syngnathidae)

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    Sperm cells are highly diversified in animals, and considerable research effort has focused on variation in sperm morphology among species. Surprisingly, little is known about intraspecific variation in sperm morphology. We analysed within- and between-male variation in mature sperm traits in two brackish water populations of the pipefish Syngnathus abaster. Four morphometric parameters, such as the width and length of the head (including nucleus, and midpiece), length of flagellum and total sperm length were taken into account. The differences in all morphometric parameters analysed between populations were not statistically significant. Moreover, the multidimensional scaling analysis shows that (i) the two populations seem to be indistinguishable based on their spermatozoa and (ii) there is not polymorphism, being sperm not distinguishable into discrete classes both within a single male and between males of each populations. The latter datum does not seem to support the presence of polymorphic sperm in syngnathids. Both populations, however, exhibit a high variation in all sperm traits, both among individual sperm within an ejaculate and among males within each population. The relationship between sperm traits variability and the low selection pressure determined by the absence of postcopulatory sexual selection (i.e. absence of sperm competition) is discussed

    Testis structure, spermatogenesis and sperm morphology in pipefishes of the genus Syngnathus

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    Testes, spermatogenesis and sperm morphology have been analysed in four species of the Syngnathus genus. All species show testes of unrestricted lobular type, characterized by a single germinal compartment, with central lumen, and an external tunica albuginea. The spermatogenesis occurs throughout a process of semicystic type, in which germinal spermatocysts open precociously, so germ cells complete maturation in the testis lumen. Amongst them, aflagellate and flagellate multinucleate cells are recognizable. This type of spermatogenesis may be therefore related to the reduced number of simultaneously mature sperm produced by syngnathids. Only one type of mature sperm has been identified in all examined species. It is always a monoflagellate cell, characterized by an elongated head. Elongated head has generally been correlated with the internal fertilization and/or to the production of spermatophore. As this is not the case of syngnathids, a possible function to explain the particularly elongated head of syngnathids is discussed

    Male gonads morphology, spermatogenesis and sperm ultrastructure of the seahorse Hippocampus guttulatus (Syngnathidae)

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    Testes morphology, spermatogenetic process and mature sperm ultrastructure were analysed in Hippocampus guttulatus, using both light and transmission electron microscopy. Both testes were organized in a single large germinal compartment, with a central lumen. Spermatocysts only contained spermatogonia and primary spermatocytes. Inside the testis lumen, together with mature sperm, two types of large mono-nucleate cells, flagellate and aflagellate, were present. Both types of cells were interpreted as developing germ cells precociously released inside the testis lumen, where their maturation was completed. According to the different morphological features of the nuclei, such as chromatin condensation degree, aspect of the nuclear fossa and others, the flagellate cells were unquestionably developing spermatids. On the contrary, the developmental stage of the aflagellate was more difficult to interpreted. They could be secondary spermatocytes or young spermatids. No dimorphic sperm were recognizable, the only sperm type observed have features typical of the intro-sperm reports in other syngnathids species. They had a cylindrical head, a short midpiece, characterized by two mitochondrial rings housed inside a cytoplasmic collar, and a long flagellum. These and previous data about the same topic reported on other syngnathids species were compared and discussed
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