Mitochondrial DNA analysis of introgression between adjacent taxa of rock-wallabies,Petrogalespecies (Marsupialia: Macropodidae)

Abstract

Simple, inexpensive techniques were used to analyse the mtDNA of nine chromosomally distinct populations of Petrogale. Eight of these populations occur in sequence along the Great Dividing Range of eastern Australia; six have been described as species. Diagnostic mtDNA morphs were found throughout the latitudinal ranges of four of the described species. A fifth morph spanned the ranges of two described species and three additional taxa which have been designated chromosome races. These five mtDNA morphs, and others with local distributions, were used to assess interactions between the taxa. Limited introgression was indicated across the chromosomal boundaries of P. penicillata/P. herberti and P. inornata/P. assimilis; atypical mtDNA morphs were found within the P. herberti and P. inornata chromosomal distributions. No introgression was detected between P. herberti and P. inornata, whose distributions are separated by the Fitzroy River. Nor was there evidence of recent contact between P. assimilis, P. herberti and P. purpureicollis, despite the late occupancy of parts of the intervening area by unidentified Petrogale. These data, considered in the light of information obtained from previous studies on chromosomes, allozymes and parasites, have contributed to the decision to consider all the eastern representatives of the lateralis-penicillata group of Petrogale as being specifically distinct from each other.

Molecular detection of hybridization between sympatric kangaroo species in south-eastern Australia

“…Although initially considered rare and usually deleterious among mammals, hybridization has been identified, to varying degrees, in various wild eutherian mammal taxa including cetaceans (Willis et al, 2004), seals (Lancaster et al, 2006;Kingston and Gwilliam, 2007), canids (Vila et al, 2003;Verardi et al, 2006), felids (Pierpaoli et al, 2003;Lecis et al, 2006), leporids (Thulin et al, 2006;MeloFerreira et al, 2007), martens (Kyle et al, 2003) and squirrels (Ermakov et al, 2006;Spiridonova et al, 2006). However, despite many macropodid marsupial species readily hybridizing in captivity (Close and Lowry, 1990), relatively few instances of natural hybridization have been reported in marsupials, with the exception of several parapatric rock-wallaby species (Briscoe et al, 1982;Eldridge et al, 1991;Eldridge and Close, 1992;Bee and Close, 1993). Therefore, increasing our understanding of the occurrence and frequency of hybridization across various mammalian taxa will provide greater insights into its evolutionary and ecological importance.…”

A Significant Range Extension Of The Purple-Necked Petrogale Purpureicollis Rockwallaby

“…Despite these advances, the distributional limits of P. l. purpureicollis remained unclear (Eldridge 1997), especially to the west (Gibson 2000) and the south-east (Bee and Close 1993). Although rockwallaby populations have been reported from around Winton and Aramac, no extant populations could be located during a searches in 1976 and 1984 (Bee and Close 1993;R.L.…”

“…Although rockwallaby populations have been reported from around Winton and Aramac, no extant populations could be located during a searches in 1976 and 1984 (Bee and Close 1993;R.L. Close pers.…”

“…This population is not present today. The unidentified Petrogale populations around Winton are of considerable interest, being approximately equidistant from the known ranges of three taxa ( P. l. purpureicollis, P. assimilis, P. herberti) (Bee and Close 1993). Further interest in the identity of Petrogale populations around Winton developed with the reinstatement of P. purpureicollis as a full species and further surveys were carried out during 2000 and 2001.…”

“…As P. purpureicollis is known to have distinctive mitochondrial DNA (mtDNA) (Bee and Close 1993;Eldridge et al 2001), a ~ 670 base pair (bp) fragment of the control region was amplified and sequenced as previously described (Browning et al 2001). The control region sequence from the Winton Petrogale (575 bp) was then compared to homologous sequences from six specimens of P. purpureicollis sampled throughout the species range (GenBank accession numbers AF348696-698, AY057374-377), as well as sequences from P. lateralis, P. assimilis, P. herberti and P. penicillata (Browning et al 1991;Eldridge et al 2001).…”