Comparative Chromosome Painting in Genets (Carnivora, Viverridae, Genetta), the Only Known Feliforms with a Highly Rearranged Karyotype

Abstract

Mammalian carnivores have been extensively studied by cross-species chromosome painting, which indicated a high degree of karyotypic conservatism in the cat-like suborder Feliformia relative to the ancestral carnivore karyotype (ACK). The first exception to this high degree of karyotypic conservation in feliforms was recently confirmed in genets, mesocarnivores belonging to the basal family Viverridae. Here, we present a comparative analysis of the chromosome rearrangements among 2 subspecies of the small-spotted genet <i>Genetta genetta</i> (the Iberian nominate and the Arabian <i>grantii</i>) and the panther genet <i>G. maculata</i>, the 2 most common and widespread genets, using whole-chromosome paints from the domestic cat (<i>Felis catus</i>)<i>. </i>The chromosome homology maps and the presence of numerous interstitial telomeric sites in both genet species strengthen the hypothesis that a highly rearranged karyotype compared to the ACK may occur throughout <i>Genetta</i>. The karyotype of<i> G. maculata</i> appears to have undergone more rearrangements than that of <i>G. genetta</i>, which is an older lineage. Notably, we identified a tandem fusion distinguishing <i>G. g</i>. <i>genetta</i> and <i>G. g.</i><i>grantii</i>. As <i>G. g</i>. <i>grantii</i> is morphologically and genetically distinctive, and tandem fusions have been associated with substantial postzygotic isolation in mammals, this cytogenetic finding flags the subspecies for future taxonomic investigations.