scholarly journals RADseq data reveal a lack of admixture in a mouse lemur contact zone contrary to previous microsatellite results

2021 ◽  
Author(s):  
Jelmer Wijtze Poelstra ◽  
B. Karina Montero ◽  
Jan Lüdemann ◽  
Ziheng Yang ◽  
S. Jacques Rakotondranary ◽  
...  

Despite being one of the most fundamental biological processes, the process of speciation remains poorly understood in many groups of organisms. Mouse lemurs are a species-rich genus of small primates endemic to Madagascar, whose diversity has only recently been uncovered using genetic data and is primarily found among morphologically cryptic, allopatric populations. To assess to what extent described species represent reproductively isolated entities, studies are needed in areas where mouse lemur taxa come into contact. Hybridization has previously been reported in a contact zone between two closely related mouse lemur species (Microcebus murinus and M. griseorufus) based on microsatellite data. Here, we revisit this system using RADseq data for populations in, near, and far from the contact zone, including many of the individuals that had previously been identified as hybrids. Surprisingly, we find no evidence for admixed nuclear ancestry in any of the individuals. Re-analyses of microsatellite data and simulations suggest that previously inferred hybrids were false positives and that the program NewHybrids can be particularly sensitive to erroneously inferring hybrid ancestry. Using coalescent-bases analyses, we also show an overall lack of recent gene flow between the two species, and low levels of ancestral gene flow. Combined with evidence for local syntopic occurrence, these data indicate that M. murinus and M. griseorufus are reproductively isolated. Finally, we estimate that they diverged less than a million years ago, suggesting that completion of speciation is relatively rapid in mouse lemurs. Future work should focus on the underpinnings of reproductive isolation in this cryptic primate radiation, which are mostly unknown. Our study also provides a cautionary tale for the inference of hybridization with microsatellite data.

1998 ◽  
Vol 69 (2) ◽  
pp. 106-114 ◽  
Author(s):  
Eleke Zimmermann ◽  
Sabine Cepok ◽  
Nasolo Rakotoarison ◽  
Vera Zietemann ◽  
Ute Radespiel

Primates ◽  
2011 ◽  
Vol 53 (2) ◽  
pp. 157-170 ◽  
Author(s):  
Ute Radespiel ◽  
Jonah H. Ratsimbazafy ◽  
Solofonirina Rasoloharijaona ◽  
Herimalala Raveloson ◽  
Nicole Andriaholinirina ◽  
...  

2021 ◽  
Vol 288 (1963) ◽  
Author(s):  
Johanna Henke-von der Malsburg ◽  
Peter M. Kappeler ◽  
Claudia Fichtel

Cognitive abilities covary with both social and ecological factors across animal taxa. Ecological generalists have been attributed with enhanced cognitive abilities, but which specific ecological factors may have shaped the evolution of which specific cognitive abilities remains poorly known. To explore these links, we applied a cognitive test battery (two personality, ten cognitive tests; n = 1104 tests) to wild individuals of two sympatric mouse lemur species ( n = 120 Microcebus murinus, n = 34 M. berthae ) varying in ecological adaptations but sharing key features of their social systems. The habitat and dietary generalist grey mouse lemurs were more innovative and exhibited better spatial learning abilities; a cognitive advantage in responding adaptively to dynamic environmental conditions. The more specialized Madame Berthe's mouse lemurs were faster in learning associative reward contingencies, providing relative advantages in stable environmental conditions. Hence, our study revealed key cognitive correlates of ecological adaptations and indicates potential cognitive constraints of specialists that may help explain why they face a greater extinction risk in the context of current environmental changes.


2017 ◽  
Author(s):  
Simon Knoop ◽  
Lounès Chikhi ◽  
Jordi Salmona

AbstractMadagascar is known for its unique biodiversity including its endemic primates, the lemurs. This biodiversity is threatened by deforestation, forest degradation and anthropogenic disturbances. Several mouse lemurs (genus Microcebus) have been shown to cope with habitat disturbances and degradation. However, there are 24 recognized mouse lemur species living in very different habitats, and it is not clear whether all these species respond similarly to forest degradation. Here, we review the literature on mouse lemur use of degraded habitat. We further question whether mouse lemurs show variation in degraded habitat use, with respect to forest type, conservation status and distribution range. We show that data on degraded forest (DF) use is available for 14 species and geographically aggregated in a few locations. However, data are scarce for most species, and lacking for almost half of the currently recognized species. Our results however confirm that most mouse lemur species are able to cope with, but do not necessarily respond positively to habitat degradation. We found no variation in degraded habitat use, with respect to forest type, conservation status and distribution range. However, we identified food resources availability, understory structure, predation, and tree hole availability to be the most frequently invoked factors potentially influencing DF use. The relative frequency of these four factors vary among forest types suggesting that differences may exist but still require research efforts for ecological and environmental differences among regions to be fully understood.RESEARCH HIGHLIGHTSLittle differences in the use of degraded forest (DF) between forest types, distribution ranges or conservation status.Varying factors potentially affecting DF use, such as food resources, forest structure, tree hole availability and predation.


Genetics ◽  
1997 ◽  
Vol 147 (4) ◽  
pp. 1843-1854 ◽  
Author(s):  
Nancy N FitzSimmons ◽  
Craig Moritz ◽  
Colin J Limpus ◽  
Lisa Pope ◽  
Robert Prince

Abstract The genetic structure of green turtle (Chelonia mydas) rookeries located around the Australian coast was assessed by (1) comparing the structure found within and among geographic regions, (2) comparing microsatellite loci vs. restriction fragment length polymorphism analyses of anonymous single copy nuclear DNA (ascnDNA) loci, and (3) comparing the structure found at nuclear DNA markers to that of previously analyzed mitochondrial (mtDNA) control region sequences. Significant genetic structure was observed over all regions at both sets of nuclear markers, though the microsatellite data provided greater resolution in identifying significant genetic differences in pairwise tests between regions. Inferences about population structure and migration rates from the microsatellite data varied depending on whether statistics were based on the stepwise mutation or infinite allele model, with the latter being more congruent with geography. Estimated rates of gene flow were generally higher than expected for nuclear DNA (nDNA) in comparison to mtDNA, and this difference was most pronounced in comparisons between the northern and southern Great Barrier Reef (GBR). The genetic data combined with results from physical tagging studies indicate that the lack of nuclear gene divergence through the GBR is likely due to the migration of sGBR turtles through the courtship area of the nGBR population, rather than male-biased dispersal. This example highlights the value of combining comparative studies of molecular variation with ecological data to infer population processes.


Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 667-673 ◽  
Author(s):  
W Jason Kennington ◽  
Julia Gockel ◽  
Linda Partridge

AbstractAsymmetrical gene flow is an important, but rarely examined genetic parameter. Here, we develop a new method for detecting departures from symmetrical migration between two populations using microsatellite data that are based on the difference in the proportion of private alleles. Application of this approach to data collected from wild-caught Drosophila melanogaster along a latitudinal body-size cline in eastern Australia revealed that asymmetrical gene flow could be detected, but was uncommon, nonlocalized, and occurred in both directions. We also show that, in contrast to the findings of a previous study, there is good evidence to suggest that the cline experiences significant levels of gene flow between populations.


2021 ◽  
Author(s):  
Blandine Chazarin ◽  
Margaux Benhaim-Delarbre ◽  
Charlotte Brun ◽  
Aude Anzeraey ◽  
Fabrice Bertile ◽  
...  

Grey mouse lemurs (Microcebus murinus) are a primate species exhibiting strong physiological seasonality in response to environmental energetic constraint. They notably store large amounts of lipids during early winter (EW), which are thereafter mobilized during late winter (LW), when food availability is low. In addition, they develop glucose intolerance in LW only. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, which seasonal regulations of metabolism and reproduction are comparable to their wild counterparts, during the phases of either constitution or use of fat reserves. We highlight profound changes that reflect fat accretion in EW at the whole-body level, however, without triggering an ectopic storage of fat in the liver. Moreover, molecular regulations would be in line with the lowering of liver glucose utilization in LW, and thus with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways, which suggests that glucose intolerance does not reach a pathological stage. Finally, fat mobilization in LW appeared possibly linked to reactivation of the reproductive system and enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Altogether, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while avoiding reaching a pathological state despite large lipid fluxes. This work emphasizes how the mouse lemur is of primary interest for identifying molecular mechanisms relevant to biomedical field.


Oryx ◽  
2017 ◽  
Vol 53 (4) ◽  
pp. 727-731 ◽  
Author(s):  
Malcolm S. Ramsay ◽  
Andriamahery Razafindrakoto ◽  
Shawn M. Lehman

AbstractAlthough roads are often assumed to be barriers to the dispersal of arboreal species, there has been little empirical testing of this assumption. If arboreal animals are unable to cross roads, population subdivision may occur, or resources may become inaccessible. We tested the hypothesis that Route Nationale 4 (RN4), a paved highway, was a barrier to movement and dispersal of the Endangered golden-brown mouse lemur Microcebus ravelobensis in Ankarafantsika National Park, in north-west Madagascar. During June–August 2015 we conducted a capture–mark–recapture study at three sites: two adjacent to RN4 and one within intact forest without a potential barrier. During 2,294 trap nights we captured 120 golden-brown mouse lemurs 1,032 times. In roadside habitats we captured significantly more males than females, whereas the opposite was the case in interior forest habitat. We detected eighteen crossings of highway transects by nine individuals; however, all potential dispersal events involved males. In roadside habitat, movement was significantly inhibited in both males and females. We present some of the first data on the effects of roads on movement patterns in arboreal Malagasy mammals, showing species- and sex-biased effects of roads as dispersal barriers. Our findings indicate that roads may not be complete barriers to dispersal in lemurs. We recommend that conservation managers and scientists examine explicitly the effects of roads and natural arboreal bridges in Madagascar in future studies.


1996 ◽  
Vol 74 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Christopher T. Cole ◽  
Martin I. Voskuil

Allozyme variation in 11 Minnesota populations of Lemna minor L. was studied, using 11 enzyme systems, resolving 16 putative loci from 285 plants. Significant deviations from Hardy–Weinberg frequencies occurred in several populations that had excesses of heterozygotes at several loci. While genotypic diversity and evenness measures are similar to other vegetatively reproducing plants (D = 0.541, E = 0.607), very few multilocus genotypes per population were found (mean = 4.0). Substantial population structure was evident (FST = 0.407), apparently reflecting low levels of gene flow (Nm = 0.30) despite the capacity of this species for dispersal of plantlets. This low level of gene flow and apparent low frequency of sexual reproduction has produced substantial levels of genetic divergence among populations, despite an absence of morphological differentiation. Keywords: allozymes, genetic structure, hydrophily, Lemna, vegetative dispersal, vegetative reproduction.


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