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Search Results: 1 - 10 of 306 matches for " Nicoletta Archidiacono "
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Organization and Evolution of Primate Centromeric DNA from Whole-Genome Shotgun Sequence Data
Can Alkan,Mario Ventura,Nicoletta Archidiacono,Mariano Rocchi,S. Cenk Sahinalp,Evan E Eichler
PLOS Computational Biology , 2007, DOI: 10.1371/journal.pcbi.0030181
Abstract: The major DNA constituent of primate centromeres is alpha satellite DNA. As much as 2%–5% of sequence generated as part of primate genome sequencing projects consists of this material, which is fragmented or not assembled as part of published genome sequences due to its highly repetitive nature. Here, we develop computational methods to rapidly recover and categorize alpha-satellite sequences from previously uncharacterized whole-genome shotgun sequence data. We present an algorithm to computationally predict potential higher-order array structure based on paired-end sequence data and then experimentally validate its organization and distribution by experimental analyses. Using whole-genome shotgun data from the human, chimpanzee, and macaque genomes, we examine the phylogenetic relationship of these sequences and provide further support for a model for their evolution and mutation over the last 25 million years. Our results confirm fundamental differences in the dispersal and evolution of centromeric satellites in the Old World monkey and ape lineages of evolution.
Hominoid chromosomal rearrangements on 17q map to complex regions of segmental duplication
Maria Cardone, Zhaoshi Jiang, Pietro D'Addabbo, Nicoletta Archidiacono, Mariano Rocchi, Evan E Eichler, Mario Ventura
Genome Biology , 2008, DOI: 10.1186/gb-2008-9-2-r28
Abstract: Human bacterial artificial chromosome/p1 artificial chromosome probes spanning the length of chromosome 17 were used in FISH experiments on great apes, Old World monkeys and New World monkeys to study the evolutionary history of this chromosome. We observed that the macaque marker order represents the ancestral organization. Human, chimpanzee and gorilla homologous chromosomes differ by a paracentric inversion that occurred specifically in the Homo sapiens/Pan troglodytes/Gorilla gorilla ancestor. Detailed analyses of the paracentric inversion revealed that the breakpoints mapped to two regions syntenic to human 17q12/21 and 17q23, both rich in segmental duplications.Sequence analyses of the human and macaque organization suggest that the duplication events occurred in the catarrhine ancestor with the duplication blocks continuing to duplicate or undergo gene conversion during evolution of the hominoid lineage. We propose that the presence of these duplicons has mediated the inversion in the H. sapiens/P. troglodytes/G. gorilla ancestor. Recently, the same duplication blocks have been shown to be polymorphic in the human population and to be involved in triggering microdeletion and duplication in human. These results further support a model where genomic architecture has a direct role in both rearrangement involved in karyotype evolution and genomic instability in human.Karyotype evolution was first studied by classical cytogenetics based on comparison of banding pattern and, more recently, using molecular cytogenetic tools such as fluorescence in situ hybridization (FISH). Chromosome painting and reciprocal chromosome painting, in particular, have delineated the organization of the karyotype in the primate ancestor [1,2] and in the mammalian ancestor [3-7]. Chromosome painting libraries alone cannot detect marker order arrangement along chromosomes. In contrast, bacterial artificial chromosome (BAC) clones in FISH experiments, defining the marker order, can be used
Refinement of a chimpanzee pericentric inversion breakpoint to a segmental duplication cluster
Devin P Locke, Nicoletta Archidiacono, Doriana Misceo, Maria Cardone, Stephane Deschamps, Bruce Roe, Mariano Rocchi, Evan E Eichler
Genome Biology , 2003, DOI: 10.1186/gb-2003-4-8-r50
Abstract: Here we employed a comparative fluorescence in situ hybridization approach, using probes selected from a combination of physical mapping, genomic sequence, and segmental duplication analyses to narrow the breakpoint interval of a pericentric inversion in chimpanzee involving the orthologous human 15q11-q13 region. We have refined the inversion breakpoint of this chimpanzee-specific rearrangement to a 600 kilobase (kb) interval of the human genome consisting of entirely duplicated material. Detailed analysis of the underlying sequence indicated that this region comprises multiple segmental duplications, including a previously characterized duplication of the alpha7 neuronal nicotinic acetylcholine receptor subunit gene (CHRNA7) in 15q13.3 and several Golgin-linked-to-PML, or LCR15, duplications.We conclude that, on the basis of experimental data excluding the CHRNA7 duplicon as the site of inversion, and sequence analysis of regional duplications, the most likely rearrangement site is within a GLP/LCR15 duplicon. This study further exemplifies the genomic plasticity due to the presence of segmental duplications and highlights their importance for a complete understanding of genome evolution.The karyotypes of humans and the African and Asian great apes are remarkably well conserved, with relatively few large-scale chromosomal changes among these species despite the considerable phenotypic and biological differences between hominoids [1-3]. This conservation is particularly relevant in comparisons between the human (Homo sapiens; HSA) and common chimpanzee (Pan troglodytes; PTR) genomes, for in order to completely ascertain the evolution of our own lineage it is necessary to understand what differentiates us at the genomic level from our closest relatives. Furthermore, insight into the mechanism(s) underlying primate chromosomal evolution can be obtained from the molecular characterization of species-specific rearrangement breakpoints. Recent analyses of synteny disrup
Independent centromere formation in a capricious, gene-free domain of chromosome 13q21 in Old World monkeys and pigs
Maria Cardone, Alicia Alonso, Michele Pazienza, Mario Ventura, Gabriella Montemurro, Lucia Carbone, Pieter J de Jong, Roscoe Stanyon, Pietro D'Addabbo, Nicoletta Archidiacono, Xinwei She, Evan E Eichler, Peter E Warburton, Mariano Rocchi
Genome Biology , 2006, DOI: 10.1186/gb-2006-7-10-r91
Abstract: Chromosome 13 evolution was studied, using FISH experiments, across several diverse superordinal phylogenetic clades spanning >100 million years of evolution. The analysis revealed exceptional conservation among primates (hominoids, Old World monkeys, and New World monkeys), Carnivora (cat), Perissodactyla (horse), and Cetartiodactyla (pig). In contrast, the centromeres in both Old World monkeys and pig have apparently repositioned independently to a central location (13q21). We compared these results to the positions of two human 13q21 neocentromeres using chromatin immunoprecipitation and genomic microarrays.We show that a gene-desert region at 13q21 of approximately 3.9 Mb in size possesses an inherent potential to form evolutionarily new centromeres over, at least, approximately 95 million years of mammalian evolution. The striking absence of genes may represent an important property, making the region tolerant to the extensive pericentromeric reshuffling during subsequent evolution. Comparison of the pericentromeric organization of chromosome 13 in four Old World monkey species revealed many differences in sequence organization. The region contains clusters of duplicons showing peculiar features.Human neocentromeres are functional, analphoid centromeres that emerge epigenetically in ectopic chromosomal regions [1-4]. In the majority of cases, neocentromeres appear to rescue the mitotic stability of acentric chromosomal fragments, often giving rise to aneuploidy [5]. Studies on the evolutionary history of human chromosomes have shown that the centromere can reposition along the chromosome without marker order variation or leading to aneuploidy. This phenomenon is known as 'centromere repositioning' (CR) and has been reported in primates [6-11], in non-primate placental mammals [12,13], marsupials [14], birds [15], and plants [16].Recently, two cases of 'repositioned' centromeres in otherwise normal individuals were fortuitously discovered [11,17]. These two case
EUS in portal hypertension
Archidiacono P.,Karavitis P.
Annals of Gastroenterology , 2007,
Abstract: SUMMARY The mechanisms involved in the development and natural history of Portal Hypertension are far away to be clearly known. Endoscpic Ultrasonography is a branch of gastrointestinal endoscopy, that has achieved a world wide acceptance in the evaluation of many clinical settings during last years. Some of these indications are now clearly stated, while others are under evaluation. The possibility to apply EUS in portal hypertension has been studied by several Authors during last years, both in the diagnosis and in the management of this complication of liver cirrhosis. In fact EUS studies have been performed on the hemodynamic assessment of portal vein system, azygos vein, varices and portosystemic collaterals. In the management of portal hypertension EUS has been studied both for the assessment of the efficacy of drug therapy and for endocopic treatment. Data obtained are preliminary but very interesting and promising, and have given a great impulse to this field of clinical research. Key Words: Endoscopie ultrasonography, portal hypertension, bleeding, doppler
Updated constraints on non-standard neutrino interactions from Planck
Maria Archidiacono,Steen Hannestad
Physics , 2013, DOI: 10.1088/1475-7516/2014/07/046
Abstract: We provide updated bounds on non-standard neutrino interactions based on data from the Planck satellite as well as auxiliary cosmological measurements. Two types of models are studied - A Fermi-like 4-point interaction and an interaction mediated by a light pseudoscalar - and we show that these two models are representative of models in which neutrinos either decouple or recouple in the early Universe. Current cosmological data constrain the effective 4-point coupling to be $G_X \leq \left(0.06 \, {\rm GeV}\right)^{-2}$, corresponding to $G_X \leq 2.5 \times 10^7 G_F$. For non-standard pseudoscalar interactions we set a limit on the diagonal elements of the dimensionless coupling matrix, $g_{ij}$, of $g_{ii} \leq 1.2 \times 10^{-7}$. For the off-diagonal elements which induce neutrino decay the bound is significantly stronger, corresponding to $g_{ij} \leq 2.3 \times 10^{-11}(m/0.05 \, {\rm eV})^{-2}$, or a lifetime constraint of $\tau \geq 1.2 \times 10^{9} \, {\rm s} \, (m/0.05 \, {\rm eV})^{3} \,$. This is currently the strongest known bound on this particular type of neutrino decay. We finally note that extremely strong neutrino self-interactions which completely suppress anisotropic stress over all of cosmic history are very highly disfavored by current data ($\Delta \chi^2 \sim 10^4$).
Le fonti slave dell’esperanto Le fonti slave dell’esperanto
Nicoletta Marcialis
Studi Slavistici , 2012,
Abstract:
Cooperative Hypertext: An Educational Example
Nicoletta SALA
The Turkish Online Journal of Distance Education , 2002,
Abstract:
La tutela del paesaggio: percorsi giuridici
Nicoletta Ferrucci
Aestimum , 2007,
Abstract:
Lucia Saetta e Cristina Vannini Parenti (a cura di), Blog & Nuvole. Un incontro tra la scrittura della rete e l’arte del fumetto.
Nicoletta Vallorani
Altre Modernità , 2009,
Abstract: Lucia Saetta e Cristina Vannini Parenti (a cura di), Blog & Nuvole. Un incontro tra la scrittura della rete e l’arte del fumetto.
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