Mitochondrial phylogeography of the Eurasian beaverCastor fiberL.

Abstract

Nucleotide variation in an approximately 490 bp fragment of the mitochondrial DNA control region (mtDNA CR) was used to describe the genetic variation and phylogeographical pattern in the Eurasian beaver ( Castor fiber ) over its entire range. The sampling effort was focused on the relict populations that survived a drastic population bottleneck, caused by overhunting, at the end of the 19th century. A total of 152 individuals grouped into eight populations representing all currently recognized subspecies were studied. Sixteen haplotypes were detected, none of them shared among populations. Intrapopulation sequence variation was very low, most likely a result of the severe bottleneck. Extreme genetic structure could result from human-mediated extinction of intermediate populations, but it could also be an effect of prior substantial structuring of the beaver populations with watersheds of major Eurasian rivers acting as barriers to gene flow. Phylogenetic analysis revealed the presence of two mtDNA lineages: eastern (Poland, Lithuania, Russia and Mongolia) and western (Germany, Norway and France), the former comprising more divergent haplotypes. The low level of sequence divergence of the entire cytochrome b gene among six individuals representing six subspecies suggests differentiation during the last glacial period and existence of multiple glacial refugia. At least two evolutionary significant units (ESU) can be identified, the western and the eastern haplogroup. The individual relict populations should be regarded as management units, the eastern subspecies possibly also as ESUs. Guidelines for future translocations and reintroductions are proposed.

Assessing genetic variation and population structure of invasive North American beaver (Castor Canadensis Kuhl, 1820) in Tierra Del Fuego (Argentina)

“…The extreme genetic variation showed by cytochrome b and especially D-loop haplotypes is probably a consequence of migration and reinvasion processes between Chilean and Argentinean populations. Similar genetic variability has been observed between several European and Eurasian beaver populations thought to have undergone extensive bottlenecks or founder effects (Ellegren et al 1993(Ellegren et al , 1994Ducroz et al 2005;Durka et al 2005).…”

“…Cytochrome b gene was amplified using a combination of primers MVZ 05 -L14115 (5 0 -CGAAGCTTG ATATGAAAAACCATCGTTG-3 0 ) and MVZ14 -H15825 (5 0 -GGTCTTCATCTYHGGYTTACAAGA C-3 0 ) (Smith and Patton 1993), 12S rRNA gene with L1091 (5 0 -AAAAAGCTTCAAACTGGGATTAGA TACCCCACTAT-3 0 ) and H1478 (5 0 -TGACTGCA-GAGGGTGACGGGCGGTGTGT-3 0 ) described by Kocher et al (1989). Hypervariable domain I (HVI) (Saccone et al 1987) of the control region (D-loop) was amplified using the following universal primers: Thr-L15926 (5 0 -CAATTCCCCGGTCTTGTAAACC-3 0 ) located in the neighboring tRNA-pro gene and DL-H16340 (5 0 -CCTGAAGTAGGAACCAGATG-3 0 ) (Vila et al 1999;Ducroz et al 2005;Durka et al 2005). Amplification of the double-stranded product was performed in 25 ll or 50 ll total reaction volume with two polymerase chain reaction (PCR) thermal profiles using Thermus aquaticus DNA-polymerase in a MJ thermocycler.…”

“…Relatively low genetic variability has been observed in several natural populations, such as muskrat Ondatra zibethicus introduced in Finland, or beaver C. fiber in Europe (Ellegreen et al 1993;Durka et al 2005) and it has been attributed to extensive population bottleneck phenomena. In the case of C. canadensis introduced in Tierra del Fuego, the impressive growth of this population suggests that its viability and fertility were not drastically affected by genetic founder effect.…”

“…To address these goals, we analyzed a hypervariable partial sequence of the mitochondrial DNA (mtDNA) D-loop (or control region), which has already proved to be suitable for investigations at the population level in several mammalian species Durka et al 2005;Reyes et al 2003;Matson and Baker 2001;Matsuhashi et al 1999, Douzery andRandi 1997;). We also analyzed segments of cytochrome b and 12S rRNA as sources of complementary information about the genetic structure of the population.…”

Mitochondrial genetic diversity and structuring of northernwhite-breasted hedgehogs from the Central Balkans

“…In response to ever-increasing anthropogenic changes to natural ecosystems, genetic monitoring through the usage of different molecular markers is the best estimator of natural populations' sustainability, since genetic variability underpins populations' long-term potential for survival and adaptation (Palsbøll et al, 2007;Schwartz et al, 2007). Mitochondrial DNA is one of the most extensively used molecular markers in determining molecular diversity and phylogeography of many species (e.g., Castor fiber (Durka et al, 2005), Cervus elaphus (Zachos and Hartl, 2011), Sus scrofa (Alexandri et al, 2012;Veličković et al, 2015), Ursus actros (Hirata et al, 2013)), given the high evolutionary rate and lack of recombination (Avise, 2004). Even though analyses based solely on mtDNA have their own limitations due to mtDNA being a single locus marker with an effective population size of one-fourth of nuclear autosomal sequences, it is still a choice in preliminary analyses of genetic variability of wild populations.…”