Search results for " genome evolution"
showing 5 items of 5 documents
Chromosomal distribution of interstitial telomeric sequences in nine neotropical primates (Platyrrhini): possible implications in evolution and phylo…
2016
To localize interstitial telomeric sequences (ITSs) and to test whether their pattern of distribution could be linked to chromosomal evolution, we hybridized telomeric sequence probes (peptide nucleic acid, PNA) on metaphases of New World monkeys: Callithrix argentata, Callithrix jacchus, Cebuella pygmaea, Saguinus oedipus, Saimiri sciureus, Aotus lemurinus griseimembra, Aotus nancymaae (Cebidae), Lagothrix lagotricha (Atelidae) and Callicebus moloch (Pithecidae), characterized by a rapid radiation and a high rate of chromosomal rearrangements. Our analysis of the probe signal localization allowed us to show in all the species analysed, as normally, the telomeric location at the terminal en…
The Compass-like Locus, Exclusive to the Ambulacrarians, Encodes a Chromatin Insulator Binding Protein in the Sea Urchin Embryo
2013
Chromatin insulators are eukaryotic genome elements that upon binding of specific proteins display barrier and/or enhancer-blocking activity. Although several insulators have been described throughout various metazoans, much less is known about proteins that mediate their functions. This article deals with the identification and functional characterization in Paracentrotus lividus of COMPASS-like (CMPl), a novel echinoderm insulator binding protein. Phylogenetic analysis shows that the CMPl factor, encoded by the alternative spliced Cmp/Cmpl transcript, is the founder of a novel ambulacrarian-specific family of Homeodomain proteins containing the Compass domain. Specific association of CMPl…
Evolution of small prokaryotic genomes
2015
As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ∼800 genes as well as endosymbiotic bacteria with as few as ∼140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokar…
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…
Genome degeneration and adaptation in a nascent stage of symbiosis
2014
Symbiotic associations between animals and microbes are ubiquitous in nature, with an estimated 15% of all insect species harboring intracellular bacterial symbionts. Most bacterial symbionts share many genomic features including small genomes, nucleotide composition bias, high coding density, and a paucity of mobile DNA, consistent with long-term host association. In this study, we focus on the early stages of genome degeneration in a recently derived insect-bacterial mutualistic intracellular association. We present the complete genome sequence and annotation of Sitophilus oryzae primary endosymbiont (SOPE). We also present the finished genome sequence and annotation of strain HS, a close…