Chromosome painting shows that skunks (Mephitidae, Carnivora) have highly rearranged karyotypes

Abstract

The karyotypic relationships of skunks (Mephitidae) with other major clades of carnivores are not yet established. Here, multi-directional chromosome painting was used to reveal the karyological relationships among skunks and between Mephitidae (skunks) and Procyonidae (raccoons). Representative species from three genera of Mephitidae (Mephitis mephitis, 2n = 50; Mephitis macroura, 2n = 50; Conepatus leuconotus, 2n = 46; Spilogale gracilis, 2n = 60) and one species of Procyonidae (Procyon lotor, 2n = 38) were studied. Chromosomal homology was mapped by hybridization of five sets of whole-chromosome paints derived from stone marten (Martes foina, 2n = 38), cat, skunks (M. mephitis; M. macroura) and human. The karyotype of the raccoon is highly conserved and identical to the hypothetical ancestral musteloid karyotype, suggesting that procyonids have a particular importance for establishing the karyological evolution within the caniforms. Ten fission events and five fusion events are necessary to generate the ancestral skunk karyotype from the ancestral carnivore karyotype. Our results show that Mephitidae joins Canidae and Ursidae as the third family of carnivores that are characterized by a high rate of karyotype evolution. Shared derived chromosomal fusion of stone marten chromosomes 6 and 14 phylogenetically links the American hog-nosed skunk and eastern spotted skunk.

Comparative Chromosome Painting in Carnivora and Pholidota

“…The ancestral karyotype of Carnivora has been described or discussed several times [Wurster-Hill and Gray, 1975;Dutrillaux and Couturier, 1983;Fronicke et al, 1997;Murphy et al, 2001b;Nash et al, 2008;Perelman et al, 2008;Nie et al, 2012]. Table 3 provides the correspondence of ACK chromosomes with feline ( Felis catus , FCA), dog ( Canis familiaris , CFA), stone marten ( Martes foina , MFO) and human ( Homo sapiens , HSA) chromosomes as well as with previously suggested ancestral carnivore karyotypes.…”

“…Only 2 representatives of Procyonidae, both from the subfamily Procyoninae (Procyon lotor and Bassariscus astutus) , have been studied by chromosome painting [Nash et al, 2008;Perelman et al, 2008]. Their karyotypes differ only by 1 inversion, revealed by dog painting probes (ACK13) [Nie et al, 2012], but otherwise they represent well the ancestral musteloid karyotype (AMK).…”

Conepatus leuconotus (Carnivora: Mephitidae)

“…C-bands are localized at the centromeres, but chromosomes 16, 19, and the Y chromosome display large pericentromeric C-bands. The metacentric X-chromosome has a C-positive centromeric region and the Y-chromosome is small and subtelocentric (Perelman et al 2008).…”

Chromosomal rearrangements and karyotype evolution in carnivores revealed by chromosome painting

“…During the last two decades, chromosome-specific painting probes have been made for nine carnivores: the domestic cat ( Felis catus , FCA) (Wienberg et al , 1997), the domestic dog ( Canis familiaris , CFA) (Breen et al , 1999a; Yang et al , 1999; Graphodatsky et al , 2000a), the red fox ( Vulpes vulpes , VVU) (Yang et al , 1999), the Japanese raccoon dog ( Nyctereutes procyonoides , NPR) (Nash et al , 2001), the American mink ( Mustela vision , MVI) (Graphodatsky et al , 2002), the stone marten ( Martes foina , MFO) (Nie et al , 2002), the giant panda ( Ailuropoda melanoleuca , AME) (Nash et al , 1998), the striped skunk ( Mephitis mephitis , MME) and the hooded skunk ( Mephitis macroura , MMA) (Perelman et al , 2008). A series of comparative chromosome maps have been established among carnivores, and karyotypic phylogenetic relationships in different carnivore groups have been revisited by chromosome painting (Nash et al , 1998, 2001, 2008; Graphodatsky et al , 2000a, 2001, 2002, 2008; Nie et al , 2002; Tian et al , 2004; Perelman et al , 2005, 2008).…”