166 research outputs found
Evoluzione del cromosoma 4 umano mediante mappaggio di sonde sub cromosomiche in Platyrrhinae, Primates
italian
Mapping CAP-A satellite DNAs by FISH in Sapajus cay paraguay and S. macrocephalus (Platyrrhini, Primates)
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 CapA 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 pair was detected on S. macrocephalus. The
analysis of the results, compared with previous literature data on other phylogenetically
close New World species, shows that Cap-A satellite sequences have a genus-specific
pattern, but with slight species-specific patterns that are useful as phylogenetic and taxonomic markers
Comparative Cytogenetics Allows the Reconstruction of Human Chromosome History: The Case of Human Chromosome 13
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; furthermore, it has been hypothesised to have a complex origin in eutherian mammals which has still not been completely clarified
Chromosome Painting in Cercopithecus petaurista (Schreber, 1774) Compared to Other Monkeys of the Cercopithecini Tribe (Catarrhini, Primates)
The Cercopithecini tribe includes terrestrial and arboreal clades whose relationships are
controversial, with a high level of chromosome rearrangements. In order to provide new insights
on the tribe’s phylogeny, chromosome painting, using the complete set of human syntenic probes,
was performed in Cercopithecus petaurista, a representative species of the Cercopithecini tribe. The
results show C. petaurista with a highly rearranged karyotype characterized by the fission of human
chromosomes 1, 2, 3, 5, 6, 8, 11, and 12. These results compared with the literature data permit us to
confirm the monophyly of the Cercopithecini tribe (fissions of chromosomes 5 and 6), as previously
proposed by chromosomal and molecular data. Furthermore, we support the monophyly of the
strictly arboreal Cercopithecus clade, previously proposed by the molecular approach, identifying
chromosomal synapomorphies (fissions of chromosomes 1, 2, 3, 11, 12). We also add additional
markers that can be useful for deciphering arboreal Cercopithecini phylogeny. For example, the
fission of chromosome 8 is synapomorphy linking C. petaurista, C. erythrogaster, and C. nictitans among
the arboreal species. Finally, a telomeric sequence probe was mapped on C. petaurista, showing only
classic telomeric signals and giving no support to a previous hypothesis regarding a link between
interspersed telomeric sequences in high rearranged genome
Centromeric enrichment of LINE-1 retrotransposon in two species of South American monkeys Alouatta belzebul and Ateles nancymaae (Platyrrhini, Primates)
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 hybridiza-tion (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 distribution led us to hypothesize that LINE 1 sequences may have a role in the centromere architecture and karyotype organization of platyrrhine genome
Phylogenomics of species from four genera of New World monkeys by flow sorting and reciprocal chromosome painting
Background: The taxonomic and phylogenetic relationships of New World monkeys (Platyrrhini) are difficult to
distinguish on the basis of morphology and because diagnostic fossils are rare. Recently, molecular data have led to a
radical revision of the traditional taxonomy and phylogeny of these primates. Here we examine new hypotheses of
platyrrhine evolutionary relationships by reciprocal chromosome painting after chromosome flow sorting of species
belonging to four genera of platyrrhines included in the Cebidae family: Callithrix argentata (silvered-marmoset), Cebuella
pygmaea (pygmy marmoset), Callimico goeldii (Goeldi's marmoset) and Saimiri sciureus (squirrel monkey). This is the first
report of reciprocal painting in marmosets.
Results: The paints made from chromosome flow sorting of the four platyrrhine monkeys provided from 42 to 45
hybridization signals on human metaphases. The reciprocal painting of monkey probes on human chromosomes revealed
that 21 breakpoints are common to all four studied species. There are only three additional breakpoints. A breakpoint
on human chromosome 13 was found in Callithrix argentata, Cebuella pygmaea and Callimico goeldii, but not in Saimiri
sciureus. There are two additional breakpoints on human chromosome 5: one is specific to squirrel monkeys, and the
other to Goeldi's marmoset.
Conclusion: The reciprocal painting results support the molecular genomic assemblage of Cebidae. We demonstrated
that the five chromosome associations previously hypothesized to phylogenetically link tamarins and marmosets are
homologous and represent derived chromosome rearrangements. Four of these derived homologous associations tightly
nest Callimico goeldii with marmosets. One derived association 2/15 may place squirrel monkeys within the Cebidae
assemblage. An apparently common breakpoint on chromosome 5q33 found in both Saimiri and Aotus nancymae could be
evidence of a phylogenetic link between these species. Comparison with previous reports shows that many syntenic
associations found in platyrrhines have the same breakpoints and are homologous, derived rearrangements showing that
the New World monkeys are a closely related group of species. Our data support the hypothesis that the ancestral
karyotype of the Platyrrhini has a diploid number of 2n = 54 and is almost identical to that found today in capuchin
monkeys; congruent with a basal position of the Cebidae among platyrrhine families
Ciona robusta macrophage migration inhibitory factor (Mif1 and Mif2) genes are differentially regulated in the lipopolysaccharide-challenged pharynx
The effects of lipopolysaccharide (LPS) on Mif (macrophage migration inhibitory factor) gene expression in the pharynx (haemapoetic tissue) of Ciona robusta were investigated using quantitative reverse-transcription PCR (qRT-PCR) and in situ
hybridisation (ISH). To verify the induction of an inflammatory response in the pharynx, a qRT-PCR analysis was performed to evaluate the change in the expression of
proinflammatory marker genes such as Mbl, Ptx-like, Tnf-α and Nf-kb, which were
shown to be upregulated 1 h post LPS challenge. The change in the expression of the
two Mif paralogs in the pharynx was assessed before and after stimulation, and qRTPCR and ISH results showed that, although Mif2 and Mif2 were expressed in clusters
of haemocytes in pharynx vessels, only Mif1 expression increased after LPS stimulation. This indicates that the Mif genes are differently regulated and respond to different ambient inputs that need further analysis
Retrotransposon mapping in spider monkey genomes of the family Atelidae (Platyrrhini, Primates) shows a high level of LINE-1 amplification
To investigate the distribution of LINE-1 repeat sequences, a
LINE-1 probe was Fluorescence In Situ Hybridized (FISH) on the
chromosomes of Ateles geoffroyi and Ateles fusciceps (Atelidae); a
LINE-1 probe was also mapped on Cebuella pygmaea (Cebidae)
and used as an outgroup for phylogenetic comparison. Ateles spider
monkeys have a highly rearranged genome and are an ideal model
for testing whether LINE-1 is involved in genome evolution. The
LINE-1 probe has been mapped in the two Atelidae species for the
first time, revealing a high accumulation of LINE-1 sequences
along chromosomal arms, including telomeres, and a scarcity of
LINE-1 signals at centromere positions. LINE-1 mapping in C. pygmaea (Cebidae) revealed signals at centromere positions and along
chromosome arms, which was consistent with previous published
data from other Cebidae species. In a broader sense, the results were
analyzed in light of published data on whole-chromosomal human
probes mapped in these genomes. This analysis allows us to speculate about the presence of LINE-1 sequences at the junction of
human chromosomal syntenies, as well as a possible link between
these sequences and chromosomal rearrangements
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