Molecular phylogeny and taxonomic revision of the sportive lemurs (Lepilemur, Primates)

Abstract

Background: The number of species within the Malagasy genus Lepilemur and their phylogenetic relationships is disputed and controversial. In order to establish their evolutionary relationships, a comparative cytogenetic and molecular study was performed. We sequenced the complete mitochondrial cytochrome b gene (1140 bp) from 68 individuals representing all eight sportive lemur species and most major populations, and compared the results with those obtained from cytogenetic studies derived from 99 specimens.

Results: Interspecific genetic variation, diagnostic characters and significantly supported phylogenetic relationships were obtained from the mitochondrial sequence data and are in agreement with cytogenetic information. The results confirm the distinctiveness of Lepilemur ankaranensis, L. dorsalis, L. edwardsi, L. leucopus, L. microdon, L. mustelinus, L. ruficaudatus and L. septentrionalis on species level. Additionally, within L. ruficaudatus large genetic differences were observed among different geographic populations. L. dorsalis from Sahamalaza Peninsula and from the Ambanja/Nosy Be region are paraphyletic, with the latter forming a sister group to L. ankaranensis.

Conclusion: Our results support the classification of the eight major sportive lemur taxa as independent species. Moreover, our data indicate further cryptic speciation events within L. ruficaudatus and L. dorsalis. Based on molecular data we propose to recognize the sportive lemur populations from north of the Tsiribihina River, south of the Betsiboka River, and from the Sahamalaza Peninsula, as distinct species.

Figure 1

Distribution of Lepilemur species (based on [25]). Circles indicate origin of analysed individuals (abbreviations are listed in additional file 1). Labelled rivers represent possible biogeographical barriers. Question marks indicate areas with ambiguous or missing information on Lepilemur distribution.

Figure 2

Comparison of the half karyotypes of Lepilemur dorsalis from Sahamalaza Peninsula (left) and Ambanja (right). No differences in the R-banding pattern were detected.

Figure 3

Comparison of the half karyotypes of Lepilemur ruficaudatus from Andramasay (left) and Kirindy/CFPF (right). No differences in the R-banding pattern were detected.

Figure 4

Comparison of the half karyotypes of Lepilemur ruficaudatus from Kirindy/CFPF (left) and Anjahamena (right). No differences in the Giemsa-stained karyotypes were detected.

Figure 5

Phylogenetic relationships as obtained from complete mitochondrial cytochrome b gene sequences (39 haplotypes), with branch lengths drawn according to those estimated by the NJ algorithm and by applying the TVM + I + Γ model of sequence evolution. Abbreviations refer to those listed in additional file 1 and numbers on nodes indicate support values for internal branches (first: NJ, second: MP, third: ML) based on 1,000 bootstrap replicates (NJ, MP) or 10,000 quartet puzzling steps (ML).

Figure 6

L. aeeclis from Anjahamena during the day (a) and night (b) (Photographs by U. Thalmann).

Figure 7

L. randrianasoli from the southern bank of Manambolo River, approx. 35 km NE of type location (a) and from Ambalarano (b) (Photographs by U. Thalmann (a) and N. Andriaholinirina (b)).

Figure 8

L. sahamalazensis at its type locality Sahamalaza Peninsula (Photographs by T. Hahn (a) and R. Hilgartner (b)).