56 research outputs found
Evolutionary history of chromosome 11 featuring four distinct centromere repositioning events in Catarrhini.
Abstract Panels of BAC clones used in FISH experiments allow a detailed definition of chromosomal marker arrangement and orientation during evolution. This approach has disclosed the centromere repositioning phenomenon, consisting in the activation of a novel, fully functional centromere in an ectopic location, concomitant with the inactivation of the old centromere. In this study, appropriate panels of BAC clones were used to track the chromosome 11 evolutionary history in primates and nonprimate boreoeutherian mammals. Chromosome 11 synteny was found to be highly conserved in both primate and boreoeutherian mammalian ancestors. Amazingly, we detected four centromere repositioning events in primates (in Old World monkeys, in gibbons, in orangutans, and in the HomoâPanâGorilla (H-P-G) clade ancestor), and one in Equidae. Both H-P-G and Lar gibbon novel centromeres were flanked by large duplicons with high sequence similarity. Outgroup species analysis revealed that this duplicon was absent in phylogenetically more distant primates. The chromosome 11 ancestral centromere was probably located near the HSA11q telomere. The domain of this inactivated centromere, in humans, is almost devoid of segmental duplications. An inversion occurred in chromosome 11 in the common ancestor of H-P-G. A large duplicon, again absent in outgroup species, was found located adjacent to the inversion breakpoints. In Hominoidea, almost all the five largest duplicons of this chromosome appeared involved in significant evolutionary architectural changes
Efficient Transmission and Characterization of CreutzfeldtâJakob Disease Strains in Bank Voles
Transmission of prions between species is limited by the âspecies barrier,â which hampers a full characterization of human prion strains in the mouse model. We report that the efficiency of primary transmission of prions from CreutzfeldtâJakob disease patients to a wild rodent species, the bank vole (Clethrionomys glareolus), is comparable to that reported in transgenic mice carrying human prion protein, in spite of a low prion proteinâsequence homology between man and vole. Voles infected with sporadic and genetic CreutzfeldtâJakob disease isolates show strain-specific patterns of spongiform degeneration and pathological prion proteinâdeposition, and accumulate protease-resistant prion protein with biochemical properties similar to the human counterpart. Adaptation of genetic CreutzfeldtâJakob disease isolates to voles shows little or no evidence of a transmission barrier, in contrast to the striking barriers observed during transmission of mouse, hamster, and sheep prions to voles. Our results imply that in voles there is no clear relationship between the degree of homology of the prion protein of the donor and recipient species and susceptibility, consistent with the view that the prion strain gives a major contribution to the species barrier. The vole is therefore a valuable model to study human prion diversity and, being susceptible to a range of animal prions, represents a unique tool for comparing isolates from different species
Sulfatase modifying factor 1âmediated fibroblast growth factor signaling primes hematopoietic multilineage development
Self-renewal and differentiation of hematopoietic stem cells (HSCs) are balanced by the concerted activities of the fibroblast growth factor (FGF), Wnt, and Notch pathways, which are tuned by enzyme-mediated remodeling of heparan sulfate proteoglycans (HSPGs). Sulfatase modifying factor 1 (SUMF1) activates the Sulf1 and Sulf2 sulfatases that remodel the HSPGs, and is mutated in patients with multiple sulfatase deficiency. Here, we show that the FGF signaling pathway is constitutively activated in Sumf1â/â HSCs and hematopoietic stem progenitor cells (HSPCs). These cells show increased p-extracellular signal-regulated kinase levels, which in turn promote ÎČ-catenin accumulation. Constitutive activation of FGF signaling results in a block in erythroid differentiation at the chromatophilic erythroblast stage, and of B lymphocyte differentiation at the proâB cell stage. A reduction in mature myeloid cells and an aberrant development of T lymphocytes are also seen. These defects are rescued in vivo by blocking the FGF pathway in Sumf1â/â mice. Transplantation of Sumf1â/â HSPCs into wild-type mice reconstituted the phenotype of the donors, suggesting a cell autonomous defect. These data indicate that Sumf1 controls HSPC differentiation and hematopoietic lineage development through FGF and Wnt signaling
Il laterizio nei cantieri della Puglia centro-settentrionale tardoantica e medievale tra reimpieghi e nuove produzioni
Il laterizio nei cantieri della Puglia centro-settentrionale tardoantica e medievale tra reimpieghi e nuove costruzioni
The brick in late antique and medieval central and northern Apulia between reuse and new productions
In Roman times, in central and northern Apulia, the use of clay in construction was not intensive, but reserved for specific functions. Production seems to be concentrated in the internal areas and linked to the major urban and rural settlements. The crisis in the sector takes place in the Late Antiquity, with different times among the various sites; in the towns production stopped between the 3rd and 4th centuries AD, except for Canosa, where in the 5th and 6th centuries an exceptional manufacturing of bricks for the building, managed by the Church, flourishes. In some rural contexts workshops of specific clay artefacts are also activated in the restructuring phases between the 4th and 5th centuries AD, to integrate reused bricks and tiles.
With the exception of Faragola, production seems to have stopped in the early Middle Ages. In the advanced 11th and in 12th century when tiles reappear in the stratigraphies, but perhaps also new constructions employ bricks (Serracapriola), the manufacturing restarted.
From the 13th century the use of newly made terracotta elements becomes more evident in various contexts, culminating in the construction of the Lucera fortress, undertaken by the Angevin rulers in the last quarter of the century, built largely with modular bricks, molded in the workshops planted on site and in the surrounding area.
The elaboration of a mensiochronological curve of bricks for Lucera from the 14th to the 19th century made it possible to outline interesting and peculiar dynamics of the brick industry over the long term
Il palazzetto episcopale di Montecorvino: spunti per la storia di una diocesi dei Monti Dauni dallâanalisi comparata di fonti scritte e dati archeologici
L'articolo pone a confronto i dati archeologici acquisiti mediante lo scavo stratigrafico degli ambienti dell'episcopio con quelli desunti dall'esame delle fonti storiche relative alla diocesi di Montecorvino per sviluppare alcune riflessioni sulla fisionomia della diocesi dauna e sulle sue strutture materiali. L'aspetto âchiusoâ del complesso, apparentemente poco permeabile rispetto alla cittĂ , appare indicativa della difficoltĂ dei vescovi di affermare la propria autorevolezza e di esercitare un ruolo politico allâinterno della comunitĂ
Carta del paesaggio del Comune di Massa Lubrense:un approccio integrato tra GIS e AMC
Lâanalisi del paesaggio del comune di Massa Lubrense (Na) Ăš stata unâopportunitĂĄ
per mettere in pratica lâintegrazione tra il processo di analisi spaziale e
i processi di Analisi Multi-Criterio (AMC), partendo dalla concezione del paesaggio
introdotta dalla Convenzione Europea del Paesaggio. In particolare Ăš stato
sviluppato un Sistema di Supporto alle Decisioni spaziale costituito da un Gis
combinato con il metodo Analytic Hierarchy Process (AHP), che ha consentito
di cogliere la complessitĂĄ del territorio attraverso lâelaborazione di indicatori
spaziali. Il risultato ottenuto Ăš la redazione di una Carta della âcomplessitĂ
del paesaggioâ che individua le aree omogenee del territorio piĂș pregnanti di
significati paesaggistici
First Speleological and Biological Characterization of a Submerged Cave of the Tremiti Archipelago Geomorphosite (Adriatic Sea)
The Tremiti Islands Archipelago is located in the Central-Southern Adriatic Sea and is characterized by a strong karst activity. Due to their landscape, geological, hydrological, archaeological, and historical value, Tremiti Islands are considered a geomorphosite. We carried out a preliminary, non-destructive survey by studying the speleological and biological features of the submerged sea cave Elle, located at Cala Sorrentino (Capraia Island), representing an EU Natura 2000 Priority Habitat. Topographic (perimeter length, width, height, GPS location, depth) and hydrological parameters (temperature, dissolved oxygen, pH, irradiance, water movement) were measured and its map was produced, based on morphological measurements and biological evidence. Species composition and biotic cover were investigated by image analysis. The benthic community was dominated by poriferans, together with remarkable assemblages of scleractinians and polychaete serpulids and clearly reflected the sharp light and hydrological gradients from the entrance to the cave bottom. Furthermore, different phases were hypothesized for the genesis of the cave during sea regression and flooding periods. To be signaled is the record of Petrobiona massiliana, a sponge was protected under both Barcelona and Bern Convention and of some individuals of polychaete Serpulinae, which are still under description
Sexual and asexual reproduction in a Mediterranean Tethya (Porifera, Demospongiae) species
Background
The reproductive cycle of the recently described sponge Tethya meloni was investigated for a period of 15 months (September 2018 â November 2019) in the Mar Piccolo of Taranto (Southern Italy) and was compared with data previously collected for the other two sympatric species of the same genus known for Mediterranean Sea, T. citrina and T. aurantium.
Results
T. meloni is a gonochoric species with a sex ratio strongly shifted towards females. Asexual budding was a seasonal process, limited to few specimens. In a specimen collected in September 2018 both oocytes and buds occurred, suggesting that in T. meloni the sexual and asexual phases may coexist both at the population and individual levels.
Conclusions
The data obtained from this research compared with the available literature confirm the high temporal variability of the reproductive cycles in the Mediterranean species of Tethya, but with common general characteristics. In sexual reproduction, the oocyte production period lasts several months, with a peak between summer and autumn while spermatogenesis, shorter but with greater reproductive effort, follows the onset of oogenesis. The asexual reproduction phase of T. meloni, on the other hand, occurs in a short period and seems to have less importance in the overall reproductive process
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