Supplementary Material for: A High-Resolution Comparative Chromosome Map of Cricetus cricetus and Peromyscus eremicus Reveals the Involvement of Constitutive Heterochromatin in Breakpoint Regions
<p>Compared to humans and other mammals, rodent genomes, specifically
Muroidea species, underwent intense chromosome reshuffling in which many
complex structural rearrangements occurred. This fact makes them
preferential animal models for studying the process of karyotype
evolution. Here, we present the first combined chromosome comparative
maps between 2 Cricetidae species, <i>Cricetus cricetus</i> and <i>Peromyscus eremicus</i>, and the index species <i>Mus musculus</i> and <i>Rattus norvegicus</i>.
Comparative chromosome painting was done using mouse and rat paint
probes together with in silico analysis from the Ensembl genome browser
database. Hereby, evolutionary events (inter- and intrachromosomal
rearrangements) that occurred in <i>C. cricetus</i> and <i>P. eremicus</i>
since the putative ancestral Muroidea genome could be inferred, and
evolutionary breakpoint regions could be detected. A colocalization of
constitutive heterochromatin and evolutionary breakpoint regions in each
genome was observed. Our results suggest the involvement of
constitutive heterochromatin in karyotype restructuring of these
species, despite the different levels of conservation of the <i>C. cricetus</i> (derivative) and <i>P. eremicus</i> (conserved) genomes.</p