MtDNA reveals strong genetic differentiation among geographically isolated populations of the golden brown mouse lemur, Microcebus ravelobensis

Abstract

Microcebus ravelobensis is an endangered nocturnal primate endemic to northwestern Madagascar. This part of the island is subject to extensive human intervention leading to massive habitat destruction and fragmentation. We investigated the degree of genetic differentiation among remaining populations using mitochondrial control region sequences (479-482 bases). Nine populations were sampled from the hypothesized geographic range. The region is composed of three inter-river systems (IRSs). Samples were collected in three areas of continuous forests (CFs) and six isolated forest fragments (IFFs) of different sizes. We identified 27 haplotypes in 114 animals, with CFs and IFFs harbouring 5-6 and 1-3 haplotypes, respectively. All IFFs were significantly differentiated from each other with high F ST values and sets of unique haplotypes. The rivers constitute significant dispersal barriers with over 82% of the molecular variation being attributed to the divergence among the IRSs. The data suggest a deep and so far unknown split within the rufous mouse lemurs of northwestern Madagascar. The limited data base and the lack of ecological and morphological data do not allow definite taxonomic classification at this stage.However, the results clearly indicate that M. ravelobensis consists of three evolutionary significant units, possibly cryptic species, which warrant urgent and separate conservation efforts.

Genetic Evidence for Male and Female Dispersal in Wild Lemur catta

“…Although there is an absence of major geographic barriers to dispersal (i.e. rivers [Guschanski et al, 2007;Quéméré et al, 2010]) between the 2 locations, potential anthropogenic barriers to dispersal exist, such as deforested patches [Brinkmann et al, 2014].…”

Population Genetics in the Conservation of Cetaceans and Primates

“…For example, rivers separate genetically distinct populations in bonobos ( Pan paniscus ; Eriksson et al 2004 ), chimpanzees ( Pan troglodytes ; Gonder et al 2006 ), mandrills ( Mandrillus leucophaeus ; Telfer et al 2003 ), orangutans ( Pongo pygmaeus ; Jalil et al 2008 ), gorillas ( Gorilla spp. ; Anthony et al 2007 ), and mouse lemurs ( Microcebus ravelobensis ; Guschanski et al 2007 ). This strong effect on genetic structure is probably a result of the poor swimming abilities of many primates (Ayres and Cluttonbrock 1992 ).…”

“…In other cases, anthropogenic alterations of the environment have been implicated as geographic barriers to gene fl ow. For example, human-mediated fragmentation of forest habitats is thought to be a primary factor infl uencing genetic structure within the Yunnan snub-nosed monkey in Tibet (Liu et al 2009 ) and the mouse lemur ( M. ravelobensis ) in northwestern Madagascar (Guschanski et al 2007 ;Radespiel et al 2008 ).…”

“…Therefore, estimation of neutral genetic diversity can provide vital information regarding the vulnerability of populations. For example, mtDNA control region diversity of golden-brown mouse lemurs ( M. ravelobensis ) in northwestern Madagascar was severely reduced in small forest fragments compared to continuous forests, providing evidence that anthropogenic forest fragmentation has decreased population sizes, driven down genetic diversity, and increased population vulnerability in this species (Guschanski et al 2007 ).…”

First indications of a highland specialist among mouse lemurs (Microcebus spp.) and evidence for a new mouse lemur species from eastern Madagascar

“…Three different loci of mitochondrial DNA (partial D-loop region, cytb and COII) were amplified using the primers given in Olivieri et al (2007). PCR conditions and cycling conditions followed Guschanski et al (2007) for the D-loop/COII and Olivieri et al (2007) for cyt b. PCR products were checked for successful amplification on a 1.5% agarose gel containing 1.3 9 10 -4 mg/ml ethidium bromide. PCR products were cleaned using the standard protocol of the Invisorb Ò Spin PCRapid kit (Invitek).…”