Gene synteny comparisons between different vertebrates provide new insights into breakage and fusion events during mammalian karyotype evolution

Background Genome comparisons have made possible the reconstruction of the eutherian ancestral karyotype but also have the potential to provide new insights into the evolutionary inter-relationship of the different eutherian orders within the mammalian phylogenetic tree. Such comparisons can additio...
Ausführliche Beschreibung

Background Genome comparisons have made possible the reconstruction of the eutherian ancestral karyotype but also have the potential to provide new insights into the evolutionary inter-relationship of the different eutherian orders within the mammalian phylogenetic tree. Such comparisons can additionally reveal (i) the nature of the DNA sequences present within the evolutionary breakpoint regions and (ii) whether or not the evolutionary breakpoints occur randomly across the genome. Gene synteny analysis (E-painting) not only greatly reduces the complexity of comparative genome sequence analysis but also extends its evolutionary reach. Results E-painting was used to compare the genome sequences of six different mammalian species and chicken. A total of 526 evolutionary breakpoint intervals were identified and these were mapped to a median resolution of 120 kb, the highest level of resolution so far obtained. A marked correlation was noted between evolutionary breakpoint frequency and gene density. This correlation was significant not only at the chromosomal level but also sub-chromosomally when comparing genome intervals of lengths as short as 40 kb. Contrary to previous findings, a comparison of evolutionary breakpoint locations with the chromosomal positions of well mapped common fragile sites and cancer-associated breakpoints failed to reveal any evidence for significant co-location. Primate-specific chromosomal rearrangements were however found to occur preferentially in regions containing segmental duplications and copy number variants. Conclusion Specific chromosomal regions appear to be prone to recurring rearrangement in different mammalian lineages ('breakpoint reuse') even if the breakpoints themselves are likely to be non-identical. The putative ancestral eutherian genome, reconstructed on the basis of the synteny analysis of 7 vertebrate genome sequences, not only confirmed the results of previous molecular cytogenetic studies but also increased the definition of the inferred structure of ancestral eutherian chromosomes. For the first time in such an analysis, the opossum was included as an outgroup species. This served to confirm our previous model of the ancestral eutherian genome since all ancestral syntenic segment associations were also noted in this marsupial. Ausführliche Beschreibung

Autor*in:	Kemkemer, Claus [verfasserIn] Kohn, Matthias Cooper, David N Froenicke, Lutz Högel, Josef Hameister, Horst Kehrer-Sawatzki, Hildegard

Format:	E-Artikel
Sprache:	Englisch

Erschienen:	2009

Schlagwörter:	Segmental Duplication Fragile Site Breakpoint Region Common Fragile Site Evolutionary Breakpoint

Anmerkung:	© Kemkemer et al; licensee BioMed Central Ltd. 2009. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (

Übergeordnetes Werk:	Enthalten in: BMC evolutionary biology - London : BioMed Central, 2001, 9(2009), 1 vom: 24. Apr.
Übergeordnetes Werk:	volume:9 ; year:2009 ; number:1 ; day:24 ; month:04

Links:	Volltext

DOI / URN:	10.1186/1471-2148-9-84

Katalog-ID:	SPR026965208