Search results for " primates"

Anthropoid versus strepsirhine status of the African Eocene primates Algeripithecus and Azibius: craniodental evidence.

2009

Recent fossil discoveries have demonstrated that Africa and Asia were epicentres for the origin and/or early diversification of the major living primate lineages, including both anthropoids (monkeys, apes and humans) and crown strepsirhine primates (lemurs, lorises and galagos). Competing hypotheses favouring either an African or Asian origin for anthropoids rank among the most hotly contested issues in paleoprimatology. The Afrocentric model for anthropoid origins rests heavily on the >45 Myr old fossil Algeripithecus minutus from Algeria, which is widely acknowledged to be one of the oldest known anthropoids. However, the phylogenetic position of Algeripithecus with respect to other p…

What can chromosomes tell us about the origin of primates?

2011

Identificazione tassonomica di Aotus (Platyrrhinae) mediante la citogenetica

2015

Evolution of the Human chromosome 7: new information from the mapping of William-Breuren locus on non human primates chromosomes.

2004

Human chromosome 7 (HSA7) derives, by a pericentric inversion and a paracentric inversion, from an ancestral chromosome homologous to chromosome 10 of Pongo pygmaeus (the Asiatic Orang-Utan). Nevertheless the genesis of this autosome during primates evolution is not clear. Even if chromosome painting shows that HAS 7 synteny is highly conserved, GTG-banding comparison in Hominoidea and Cercopithecoidea indicates the probable occurrence of complex rearrangements during the evolution. In this study we used a single locus FISH approach, a powerful tool to detect fine rearrangements, in order to investigate the evolution of HAS 7. We report the chromosome mapping of Williams-Beuren syndrome loc…

The Evolution of Human Chromosome 7 Syntenies in Eutheria, with Special Attention to Primates

2004

Genetic and cytogenetic comparison in between man and non-human primates has largely contributed to the knowledge of the evolution of the Order Primates, and in particular of man. Recently, the "Chromosome painting" approach indicated a strong conservation of syntenies in Eutheria. At present, a more precise identification of breakpoints and evolutionary related rearrangements can be obtained by BAC and locus specific in situ hybridi- sation. In spite to this situation the evolutionary history of different human autosomes remains a dilemma; at the same time, high resolution banded chromosome analysis confirms to be a valuable tool for the preliminary detection of fine rearrangements. This r…

Eight million years of maintained heterozygosity in chromosome homologs of cercopithecine monkeys

2020

In the Cercopithecini ancestor two chromosomes, homologous to human chromosomes 20 and 21, fused to form the Cercopithecini specific 20/21 association. In some individuals from the genus Cercopithecus, this association was shown to be polymorphic for the position of the centromere, suggesting centromere repositioning events. We set out to test this hypothesis by defining the evolutionary history of the 20/21 association in four Cercopithecini species from three different genera. The marker order of the various 20/21 associations was established using molecular cytogenetic techniques, including an array of more than 100 BACs. We discovered that five different forms of the 20/21 association w…

Recovery of endogenous beta cell function in non-human primates following chemical diabetes induction and islet transplantation

2009

Objectives: To describe the ability of non-human primate endocrine pancreata to re-establish endogenous insulin production after chemical beta cell destruction. Research Design and Methods: Eleven monkeys (macaca fascicularis) were rendered diabetic with streptozotocin. Eight diabetic monkeys received intraportal porcine islet transplantation. Results: Two monkeys transplanted after 75 days of insulin dependent diabetes, showed recovery of endogenous C-peptide production a few weeks after transplantation, concomitant with graft failure. Histological analysis of the pancreas of these monkeys showed insulin-positive cells, single or in small aggregates scattered in the pancreas and adjacent t…

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

2012

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…

Differentiation of Trichuris species eggs from non-human primates by geometric morphometric analysis

2020

Human trichuriasis is a neglected tropical disease which affects millions of people worldwide, mostly living in low socio-economic conditions. Numerous studies have been conducted over the past 10 years to compare the different techniques for T. trichiura eggs detection. Our study provides the first geometric morphometric analysis for the specific detection of eggs of Trichuris sp. isolated from stools of macaque (M. sylvanus), colobus (C. g. kikuyensis), grivets (C. aethiops) and the Brazza's monkey (C. neglectus) from zoos in Spain. Principal Component Analysis (PCA) arises as an efficient method to determine Trichuris spp. eggs. The selected measurements to be included in the PCA were pr…