Phylogenetic studies of the genus <it>Cebus </it>(Cebidae-Primates) using chromosome painting and G-banding

<p>Abstract</p> <p>Background</p> <p>Chromosomal painting, using whole chromosome probes from humans and <it>Saguinus oedipus</it>, was used to establish karyotypic divergence among species of the genus <it>Cebus</it>, including <it>C. olivaceus</it>, <it>C. albifrons</it>, <it>C. apella robustus </it>and <it>C. apella paraguayanus</it>. Cytogenetic studies suggested that the species of this genus have conservative karyotypes, with diploid numbers ranging from 2n = 52 to 2n = 54.</p> <p>Results</p> <p>Banding studies revealed morphological divergence among some chromosomes, owing to variations in the size of heterochromatic blocks. This analysis demonstrated that <it>Cebus </it>species have five conserved human associations (i.e., 5/7, 2/16, 10/16, 14/15, 8/18 and 3/21) when compared with the putative ancestral Platyrrhini karyotype.</p> <p>Conclusion</p> <p>The autapomorphies 8/15/8 in C. albifrons and 12/15 in <it>C. olivaceus </it>explain the changes in chromosome number from 54 to 52. The association 5/16/7, which has not previously been reported in Platyrrhini, was also found in <it>C. olivaceus</it>. These data corroborate previous FISH results, suggesting that the genus <it>Cebus </it>has a very similar karyotype to the putative ancestral Platyrrhini.</p

Molecular Cytogenetic Characterization of Multiple Intrachromosomal Rearrangements in Two Representatives of the Genus Turdus (Turdidae, Passeriformes)

Turdus rufiventris and Turdus albicollis, two songbirds belonging to the family Turdidae (Aves, Passeriformes) were studied by C-banding, 18S rDNA, as well as the use of whole chromosome probes derived from Gallus gallus (GGA) and Leucopternis albicollis (LAL). They showed very similar karyotypes, with 2n = 78 and the same pattern of distribution of heterochromatic blocks and hybridization patterns. However, the analysis of 18/28S rDNA has shown differences in the number of NOR-bearing chromosomes and ribosomal clusters. The hybridization pattern of GGA macrochromosomes was similar to the one found in songbirds studied by Fluorescent in situ hybridization, with fission of GGA 1 and GGA 4 chromosomes. In contrast, LAL chromosome paintings revealed a complex pattern of intrachromosomal rearrangements (paracentric and pericentric inversions) on chromosome 2, which corresponds to GGA1q. The first inversion changed the chromosomal morphology and the second and third inversions changed the order of chromosome segments. Karyotype analysis in Turdus revealed that this genus has derived characteristics in relation to the putative avian ancestral karyotype, highlighting the importance of using new tools for analysis of chromosomal evolution in birds, such as the probes derived from L. albicollis, which make it possible to identify intrachromosomal rearrangements not visible with the use of GGA chromosome painting solely

Respective probe compositions and false color assignments are given beside each metaphase

<p><b>Copyright information:</b></p><p>Taken from "Phylogenetic studies of the genus (Cebidae-Primates) using chromosome painting and G-banding"</p><p>http://www.biomedcentral.com/1471-2148/8/169</p><p>BMC Evolutionary Biology 2008;8():169-169.</p><p>Published online 5 Jun 2008</p><p>PMCID:PMC2435554.</p><p></p