Search results for " ANTROPOLOGIA"

Susceptibility to Mycobacterium tubercolosis: importance of multiple key genes in human and nonhuman primates

2012

Chromosomal Dynamics in Cercopithecini Studied by Williams-Beuren probe mapping

2010

Chromosomal evolution in the tribe Cercopithecini and in related taxa is highly debated. Uncertainty in reconstruction is mainly related to the great genetic variability and polymorphism of the taxa. Recent molecular and karyological efforts individuate a split between genetically conservative, arbitrarily defi ned, “terrestrial” guenons and vervets, and genetically variable and derived “arboreal” guenons. We performed the mapping of WS loci probe (7q11.23) in order to verify the chromosomal dynamics of the genomes of three tree-dwelling species of the tribe: C. neglectus, C. mitis mitis, C. albogularis labiatus. Data from literature for the “ground-dwelling” Chlorocebus aethiops sabaeus ha…

The evolution of human synteny 4 by mapping sub-chromosomal specific probes in Primates

2014

Comparative cytogenetic data concerning the orthologue to human chromosome 4 in primates shows that this chromosome is conserved between humans and non-human primates. However, the degree of conservation is not as high as previously estimated. In primates it is as a rule a large submetacentric chromosome but many exceptions are known especially in taxa characterized by a high level of chromosomal rearrangements. The rearrangements that have been visualized by chromosome painting so far, which are mostly interchromosomal changes, are in fact only a fraction of the actual chromosomal changes that have occurred during evolution. Intrachromosome changes can be analysed through classical cytogen…

A Phylogenetic Analysis of Human Syntenies Revealed by Chromosome Painting in Euarchontoglires Orders

2010

To search for cytogenetic signatures that can help to clarify evolutionary affinities among the five orders within the Euarchontoglires clade, we focused on associations of conserved syntenic blocks that have been accumulated in the karyotypes of Primates (Strepsirhini and Haplorhini), five families of Rodentia, Scandentia (Tupaia belangeri), Dermoptera (Galeopterus variegatus) and Lagomorpha (Oryctolagus cuniculus). We examined available chromosome painting data to identify conserved chromosomes and chromosomal segments, and syntenic associations likely to have characterized the ancestral eutherian karyotype. The data set includes 161 characters that have been subjected to a concatenated a…

PrP Gene Polymorphism in Medieval Remains of Sicilian Sheep

2015

Encephalopathy in sheep was at first described in Ireland in 1732 and was called scrapie. Ancient DNA in archaeogenetics represents an effective method to evaluate the ancestral pedigree of living animals and track evolutionary changes occurred between the past and the present day. Since several point mutations are today widely described in modern scrapie, no data about both sequence and frequency are still available for the prion protein (PrP) gene in ancient breeds. In order to evaluate whether the haplotypes distribution in ancient sheep differed from those of the modern population we evaluated polymorphism at four well know codons of the Prp Open Reading Frame. In the present work, we c…

Mapping CAP-A satellite DNAs by FISH in Sapajus cay paraguay and S. macrocephalus (Platyrrhini, Primates)

2023

Satellite DNAs such as Cap-A sequences are potentially informative taxonomic and phylogenetic markers useful for characterizing primate genomes. They have also been used as cytogenetic markers facilitating species identification in many taxa. The aim of this work is to map Cap-A sequences by FISH (fluorescent in situ hybridization) on two Platyrrhini (Primates) species genomes, Sapajus cay paraguay and S. macrocephalus, in order to study their distribution pattern on chromosomes. The Cap-A probes showed bright signals with almost the same interstitial pattern of distribution in correspondence with C and CMA3 rich regions on six pairs of chromosomes in both Sapajus species. An additional pai…

Exploring Evolution in Ceboidea (Platyrrhini, Primates) by Williams-Beuren Probe (HSA 7q11.23) Chromosome Mapping

2007

The ancestral platyrrhine karyotype was characterised by a syntenic association of human 5 and a small segment of human 7 orthologues. This large syntenic association has undergone numerous rearrangements in various phylogenetic lines. We used a locus-specific molecular cytogenetic approach to study the chromosomal evolution of the human 7q11.23 orthologous sequences (William-Beuren syndrome, WS) in various Ceboidea (Platyrrhini) species. The fluorescent in situ hybridisation of the WS probe revealed a two-way pattern of chromosomal organisation that suggests various evolutionary scenarios. The first pattern (seen in Callimico and Saimiri ) includes a fairly simple disruption of the 7/5 syn…

Comparative Cytogenetics Allows the Reconstruction of Human Chromosome History: The Case of Human Chromosome 13

2019

Comparative cytogenetics permits the identification of human chromosomal homologies and rearrangements between species, allowing the reconstruction of the history of each human chromosome. The aim of this work is to review evolutionary aspects regarding human chromosome 13. Classic and molecular cytogenetics using comparative banding, chromosome painting, and bacterial artificial chromosome (BAC) mapping can help us formulate hypotheses about chromosome ancestral forms; more recently, sequence data have been integrated as well. Although it has been previously shown to be conserved when compared to the ancestral primate chromosome, it shows a degree of rearrangements in some primate taxa; fu…

Centromeric enrichment of LINE-1 retrotransposon in two species of South American monkeys Alouatta belzebul and Ateles nancymaae (Platyrrhini, Primat…

2022

LINE-1 sequences have been linked to genome evolution, plasticity and speciation; however, despite their importance, their chromosomal distribution is poorly known in primates. In this perspective, we used fluorescence in situ hybridization (FISH) to map LINE-1 probes onto two representative platyrrhine species, Aotus nancymaae (Cebidae) and Alouatta belzebul (Atelidae), both characterized with highly rearranged karyotypes, in order to investigate their chromosomal distribution and role and to better characterize the two genomes. We found centromeric enrichment of LINE-1 sequences on all biarmed and acrocentric chromosomes co-localized with heterochromatin C-positive bands. This distributio…

Massive LINE-1 retrotransposon enrichment in tamarins of the Cebidae family (Platyrrhini, Primates) and its significance for genome evolution

2021

To study heterochromatin distribution differences among tamarins, we applied LINE-1 probes using fluorescence in situ hybridization onto chromosomes of Saguinus mystax, Leontocebus fuscicollis, and Leontopithecus rosalia with the aim to investigate possible evolutionary implications. LINE-1 repeats were shown to be involved in genome architecture and in the occurrence of chromosomal rearrangements in many vertebrates. We found bright LINE-1 probe signals at centromeric or pericentromeric areas, GC rich, on almost all chromosomes in three tamarin species. We also found non-centromeric signals along chromosome arms. In a phylogenetic perspective, we analyzed the pattern of LINE-1 distribution…