Phylogeographic differentiation in the mitochondrial control region in the koala, Phascolarctos cinereus (Goldfuss 1817)

Abstract

The koala, Phascolarctos cinereus, is a geographically widespread species endemic to Australia, with three currently recognized subspecies: P.c. adustus, P.c. cinereus, and P.c. victor. Intraspecific variation in the mitochondrial DNA (mtDNA) control region was examined in over 200 animals from 16 representative populations throughout the species' range. Eighteen different haplotypes were defined in the approximately 860 bp mtDNA control region, as determined by heteroduplex analysis/temperature gradient gel electrophoresis (HDA/TGGE). Any single population typically possessed only one or two haplotypes yielding an average within-population haplotypic diversity of 0.180 +/- 0.003, and nucleotide diversity of 0.16%. Overall, mtDNA control region sequence diversity between populations averaged 0.67%, and ranged from 0% to 1.56%. Nucleotide divergence between populations averaged 0.51%, and ranged from 0% to 1.53%. Neighbour-joining methods revealed limited phylogenetic distinction between geographically distant populations of koalas, and tentative support for a single evolutionarily significant unit (ESU). This is consistent with previous suggestions that the morphological differences formalized by subspecific taxonomy may be interpreted as clinal variation. Significant differentiation in mtDNA-haplotype frequencies between localities suggested that little gene flow currently exists among populations. When combined with microsatellite analysis, which has revealed substantial differentiation among koala populations, we conclude that the appropriate short-term management unit (MU) for koalas is the local population.

Glacial survival of the Norwegian lemming (Lemmus lemmus) in Scandinavia: inference from mitochondrial DNA variation

“…While fossils of Lemmus have been recorded from the periglacial area in Denmark before the last glacial maximum (Bennike et al 1994), lemmings are lacking in the Danish small mammal fauna (11.5 kyr BP) (Aaris-SÖrensen 1995) during the time of post-glacial colonization of Scandinavia by mammals from the south via a land bridge (cf. Jaarola et al 1999).…”

The Paradox of Euthanizing Koalas (Phascolarctos Cinereus) to Save Populations From Elimination

“…Gene flow has been further restricted by contemporary habitat fragmentation. As a result of this analysis, the appropriate management unit for koalas was suggested to be the local population (Houlden et al 1999). The exception to the trend of population differentiation was the majority of Victorian populations (except Strzelecki Ranges and South Gippsland (Lee et al 2011)) and South Australian populations, which are all descendants of island populations in Victoria as a result of translocation programs.…”

“…Three subspecies of koala have been described but their validity has been questioned by genetic and morphological analyses (Takami et al 1998;Houlden et al 1999). The subspecies' boundaries are along state lines, but there are few barriers to dispersal of koalas across these boundaries and the subspecies are unlikely to be truly isolated.…”

“…The most informative study at the national scale is that of Houlden et al (1999) who examined variation in mitochondrial DNA from over 200 individuals from 16 populations. Their principal conclusion was a lack of support for the separation of the species into subspecies and tentative support for a single Evolutionarily Significant Unit 2 Moritz 1994 ( ) for the species.…”

The assessment of TGGE for the detection of interspecific and intergeneric DNA-marker polymorphism within Solanaceae

“…For example, these systems have been used to study bacterial communities (Gomes et al 2001;Brummer et al 2003;Fouratt et al 2003;Nishida et al 2003;Ramirez-Saad et al 2003;Chen and Banks 2004;Haruta et al 2004;Henri-Dubernet et al 2004;Luo et al 2004;Ogier et al 2004;Xu and Leff 2004), and eukaryotic communities (Carlos et al 2000;Hernan-Gomez et al 2000;Anderson and Cairney 2004;Ikenaga et al 2004;Prakitchaiwattana et al 2004;Savin et al 2004). These systems are also commonly used to screen for polymorphisms in human DNA (Toliat et al 2000;Muller et al 2001;Katzke et al 2002;Lage et al 2004;Mihic-Probst et al 2004;Saarikoski et al 2004;Sekiguchi et al 2004;Soufi et al 2004) and less commonly used in wildlife and animal population genetics (Heslewood et al 1998;Jerry and Baverstock 1998;Houlden et al 1999;Leo and Barker 2002;da Mota et al 2004;Westerdahl et al 2004). The author is not aware of any publications that involve the use of TGGE, or other related systems, for the investigation of vascular plants.…”