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

A new Robertsonian translocation, 8/23, in cattle

Summary- A new Robertsonian translocation was found in 7 animals of the Grey Ukrainian breed. The translocated chromosome, analyzed by GTG- and RBG-banding, resulted from the fusion of chromosomes 8 and 23. C-banding suggested that the translocated chromosome has a double heterochromatic block. Synaptonemal complex analysis was performed using electron microscopy. cattle / chromosome / Robertsonian translocation Résumé- Une nouvelle translocation robertsonienne bovine, 8/23. On a découvert une nouvelle translocation robertsonienne chez 7 représentants de la race Ukrainienne grise. Le chromosome fusionné, analysé par une technique de bandes GTG et RBG, est le résultat de la fusion des chromosomes 8 et 2.i. La technique de bande C suggère que le chromosome fusionné possède 2 blocs hétérochromatiques. L’analyse des complexes synaptonémiques a été effectuée au microscope électronique. bovin / chromosome / translocation robertsonienn

Segmental paleotetraploidy revealed in sterlet (Acipenser ruthenus) genome by chromosome painting

Backgroun

Supplementary Material for: Chromosome Evolution in Eulipotyphla

We integrated chromosome painting information on 5 core-insectivora species available in the literature with new Zoo-FISH data for Iberian shrew <i>(Sorex granarius)</i> and Altai mole <i>(Talpa altaica)</i>. Our analysis of these 7 species allowed us to determine the chromosomal features of Eulipotyphla genomes and to update the previously proposed ancestral karyotype for 2 main groups of the <i>Sorex </i>genus. The chromosome painting evidence with human painting probes (HSA) reveals the presence of the 2 unique associations HSA4/5 and 1/10p/12/22b, which support Eulipotyphla. There are a series of synapomorphies both for Erinaceidae (HSA3/1/5, 3/17, 11/15 and 10/20) and for Soricinae (HSA5/9, 6/7/16, 8/3/21 and 11/12/22). We found associations that link Talpidae/Erinaceidae (HSA7/8, 1/5 and 1/19p), Talpidae/Soricidae (HSA1/8/4) and Erinaceidae/Soricidae (HSA4/20 and 2/13). Genome conservation in Eulipotyphla was estimated on the basis of the number of evolutionary breaks in the ancestral mammalian chromosomes. In total, 7 chromosomes of the boreo-eutherian ancestor (BEA8 or 10, 9, 17, 18, 20–22) were retained in all eulipotyphlans studied; among them moles show the highest level of chromosome conservation. The integration of sequence data into the chromosome painting information allowed us to further examine the chromosomal syntenies within a phylogenetic perspective. Based on our analysis we offer the most parsimonious reconstruction of phylogenetic relationships in Eulipotyphla. The cytogenetic reconstructions based on these data do not conflict with molecular phylogenies supporting basal position of Talpidae in the order

Unusually extensive karyotype reorganization in four congeneric Gerbillus species (Muridae : Gerbillinae)

Comparative analysis of the G- and C-banding patterns in four morphologically poorly differentiated Gerbillus species (G. pyramidum, G. perpallidus, G. tarabuli and G. occiduus) was carried out. These gerbils have similar karyotype morphology with 2n and NF equal to 38/76, 40/76, 40/78 and 40/80, respectively. Our study revealed that possibly 70 Robertsonian (Rb) fusions, two pericentric inversions, one tandem translocation and at least 13 non-identified rearrangements have occurred during the karyotypic evolution of these species. The number of chromosomal changes by which any of these species differ from each other ranges from 33 to 49. One Rb fusion was common to two of the species, with only a single autosome- gonosome translocation shared by all four, suggesting a monophyletic origin of these karyotypically highly divergent species. Based on the chromosomal data obtained here, the systematic and geographic implications for these North African species are also discussed. Copyright (c) 2006 S. Karger AG, Base

Mapping Retrotransposon LINE-1 Sequences into Two Cebidae Species and Homo sapiens Genomes and a Short Review on Primates

This work focuses on the distribution of LINE-1 (a Long Interspersed Nuclear Element) in primates and its role during evolution and as a constituent of the architecture of primate genomes. To pinpoint the LINE-1 repeat distribution and its role among primates, LINE-1 probes were mapped onto chromosomes of Homo sapiens (Hominidae, Catarrhini), Sapajus apella, and Cebus capucinus (Cebidae, Platyrrhini) using fluorescence in situ hybridisation (FISH). The choice of platyrrhine species are due to the fact they are taxa characterised by a high level of rearrangements; for this reason, they could be a useful model for the study of LINE-1 and chromosome evolution. LINE-1 accumulation was found in the two Cebidae at the centromere of almost all acrocentric chromosomes 16-22 and on some bi-armed chromosomes. LINE-1 pattern was similar in the two species but only for chromosomes 6, 8, 10, and 18, due to intrachromosomal rearrangements in agreement with what was previously hypothesised as through g banding. LINE-1 interstitial accumulation was found in humans on the 1, 8, 9, 13-15, and X chromosomes; on chromosomes 8, 9, and 13-15, the signal was also at the centromeric position. This is in agreement with recent and complete molecular sequence analysis of human chromosomes 8 and some acrocentric ones. Thus, the hypothesis regarding a link between LINE-1 and centromeres as well as a link with rearrangements are discussed. Indeed, data analysis leads us to support a link between LINE-1 and inter- and intrachromosomal rearrangements, as well as a link between LINE-1 and structural functions at centromeres in primates