Satellite DNA at the Centromere is Dispensable for Segregation Fidelity.

The typical vertebrate centromeres contain long stretches of highly repeated DNA sequences (satellite DNA). We previously demonstrated that the karyotypes of the species belonging to the genus are characterized by the presence of satellite-free and satellite-based centromeres and represent a unique biological model for the study of centromere organization and behavior. Using horse primary fibroblasts cultured in vitro, we compared the segregation fidelity of chromosome 11, whose centromere is satellite-free, with that of chromosome 13, which has similar size and a centromere containing long stretches of satellite DNA.

Discovery and comparative analysis of a novel satellite, EC137, in horses and other equids.

Centromeres are the sites of kinetochore assembly and spindle fiber attachment and consist of protein-DNA complexes in which the DNA component is typically characterized by the presence of extended arrays of tandem repeats called satellite DNA. Here, we describe the isolation and characterization of a 137-bp-long new satellite DNA sequence from the horse genome (EC137), which is also present, even if less abundant, in the domestic donkey, the Grevy's zebra and the Burchelli's zebra. We investigated the chromosomal distribution of the EC137 sequence in these 4 species.

Transfer of a human chromosomal vector from a hamster cell line to a mouse embryonic stem cell line.

Two transchromosomic mouse embryonic stem (ES) sublines (ESMClox1.5 and ESMClox2.1) containing a human minichromosome (MC) were established from a sample of hybrid colonies isolated in fusion experiments between a normal diploid mouse ES line and a Chinese hamster ovary line carrying the MC.

A set of duplicons on human chromosome 9 is involved in the origin of a supernumerary marker chromosome.

Human chromosome 9 is involved in a number of recurrent structural rearrangements; moreover, its pericentromeric region exhibits a remarkable evolutionary plasticity. In this study we present the molecular characterization of a constitutional rearrangement, involving the 9p21.1q13 region, which led to the formation of a supernumerary marker chromosome (SMC).

Isolation from the horse genome of a new DNA transposon belonging to the Tigger family.

Tigger elements are human DNA transposons homologous to the pogo element of Drosophila melanogaster. They contain an open reading frame for a transposase very similar to the major mammalian centromere protein CENP-B. We found in the horse genome a DNA element ( Ecatig3) sharing 88% homology with human Tigger3.