Genetic Variability in mtDNA of the Silvery Gibbon: Implications for the Conservation of a Critically Endangered Species (original) (raw)
Natural History, 2005
Noninvasive genotyping was employed to see if the five allopatric subspecies of Hylobates lar gibbons could be recognized as genetically differentiated evolutionarily significant units. Phylogenetic and haplotype network analyses were used to study variation of mtDNA control region sequences among 46 allegedly unrelated H. lar gibbons in North American zoos. Although the origins of these gibbons or their parents are unknown, they are the result of multiple independent importations, and it is likely that they include representatives of several subspecies. The export of Hylobates lar gibbons from Asia involved primarily animals referable to the northern (carpenteri) and central/southern (entelloides) subspecies described from Thailand. The mtDNA control region was selected for study as it is unusually variable and phylogenetically informative in most mammals. In this sample of H. lar, however, all individuals studied had sequences very similar to one another and to the two published complete mtDNA sequences for this species. A phylogenetic tree analysis provided only weak evidence of variation and no support for the presence of genetically distinct subspecies in this sample. In contrast, the haplotype network analyses showed more variability and indicated that this sequence may be informative enough to resolve phylogeographic patterns in this species. This can now be tested by genotyping H. lar gibbons of known geographic provenance.
ZooKeys, 2021
Abstract Conservation translocation and reintroduction for the purpose of repopulating and reinforcing extirpated or depleted populations has been recognised as an important conservation tool, particularly for gibbon conservation in the immediate future. Feasibility assessments involving multiple factors, including taxonomic and genetic assessment of rescued and captive gibbons, are imperative prior to translocation and reintroduction programmes. In this study, we attempt to determine the subspecies and origin of captive Hylobateslar, White-handed gibbons, from Peninsular Malaysia to assist in future translocation and reintroduction programmes. A total of 12 captive and rescued H.lar samples were analysed using the control region segment of mitochondrial DNA. Sequence analyses and phylogenetic trees constructed using neighbour-joining, maximum likelihood, Bayesian inference, and network methods congruently differentiate all 12 captive individuals used in this study from other H.lar...
Phylogeography, Population Genetics, and Conservation of Javan Gibbons (Hylobates moloch)
International Journal of Primatology, 2019
The island of Java is heavily populated (density of >1000 people/km 2) and natural forest is found only scattered on many of the higher mountains. Forest loss reached its peak between 1850 and 1900, and although conversion and degradation have steadily reduced the available forest further, the pattern of forest fragmentation has remained fairly stable since (Koorders 1912; Whitten et al. 1996). As such, forest-dependent species, including the endemic Javan gibbon (Hylobates moloch), have been confined to isolated forest fragments for longer periods than many tropical species (Smith et al. 2017). This pattern of long-term fragmentation and isolation; the presence of relatively large (>500 individuals), intermediate (50-500 individuals), and small (<50 individuals) populations; and their extreme dependence on closed-canopy forest make the Javan gibbon a good model to study the population (conservation) genetics of tropical forest-dwelling species in a changing landscape. Kheng et al. (2018) recently presented data on the phylogeography and population genetic structure of Javan gibbons, collating data from three different studies; one from the late 1990s and two from the early 2000s, with a total of 47 gibbons. They group the samples into six areas: Ujung Kulon (UK, area inhabited by gibbons ca. 85 km 2), Mt. Halimun (HLM, ca. 270 km 2), Mt. Salak (SLK, ca. 70 km 2), Mt. Gede-Pangrango (GP, ca. 80 km 2), Mts. Masigit-Simpang-Tilu
DEStech Transactions on Computer Science and Engineering, 2017
The objective of this study was to reconstruct phylogenetic relationships of gibbons (3 genera, 11 species) deduced from complete sequenced mitochondrial genome sequences. According to conserved (C) / variable (V) sites ratio test, 9 selected protein coding genes were combined into a sequence with 9356 bases long including gaps. A resolved phylogenetic tree was obtained for the mitochondrial genome in the maximum-likelihood and maximum-parsimony analyses. In accordance with all previous morphological and molecular evidence, our results clearly supported monophyly of family Hylobatidae with predominantly strongly supported and each of the three genera with high support based on these coding genes. Among three genera, first Nomascus, next Symphalangus and at last Hylobates diverged, which identical to other previous research based on the whole mitochondrial genome. Our phylogenetic relationships of Nomascus group accord with Chan et al. (2010), only support values of a node of N. gabriellae (90%) were slight lower than Chan's result (97%). Among genus Hylobates, in our result, 6 species are involved and H. pileatus, H. lar, H. klossii, H. agilis, H. moloch and H. muelleri diverged sequentially.
Conservation Genetics, 2010
We used mtDNA sequence data from the Tana River red colobus and mangabey to determine how their population genetic structure was influenced by dispersal and habitat fragmentation. The colobus and mangabey are critically endangered primates endemic to gallery forests in eastern Kenya. The forests are a Pliocene–Pleistocene refugium that has recently undergone significant habitat loss and fragmentation due to human activities. We expected both primates to exhibit low levels of genetic diversity due to elevated genetic drift in their small populations, and to show a strong correspondence between genetic and geographic distance due to disruption of gene flow between forests by habitat fragmentation. Additionally, because mangabey females are philopatric, we expected their mtDNA variation to be homogeneous within forest patches but to be heterogeneous between patches. In contrast, colobus have a female-biased dispersal and so we expected their mtDNA variation to be homogeneous within and between forest patches. We found high levels of haplotype and nucleotide diversity as well as high levels of sequence divergence between haplotype groups in both species. The red colobus had significantly higher genetic variation than the mangabey did. Most of the genetic variation in both primates was found within forest fragments. Although both species showed strong inter-forest patch genetic structure we found no correspondence between genetic and geographic distances for the two primates. We attributed the high genetic diversity to recent high effective population size, and high sequence divergence and strong genetic structures to long-term habitat changes in the landscape.
Gee's golden langur (Trachypithecus geei) is an endangered colobine primate, endemic to the semi-evergreen and mixed-deciduous forests of Indo-Bhutan border. During the last few decades, extensive fragmentation has caused severe population decline and local extinction of golden langur from several fragments. However, no studies are available on the impact of habitat fragmentation and the genetic diversity of golden langur in the fragmented habitats. The present study aimed to estimate the genetic diversity in the Indian population of golden langur. We sequenced and analyzed around 500 bases of the mitochondrial DNA (mtDNA) hypervariable region-I from 59 fecal samples of wild langur collected from nine forest fragments. Overall, genetic diversity was high (h = 0.934, π = 0.0244) and comparable with other colobines. Populations in smaller fragments showed lower nucleotide diversity compared to the larger forest fragments. The median-joining network of haplotypes revealed a genetic structure that corresponded with the geographical distribution. The Aie and Champabati Rivers were found to be a barrier to gene flow between golden langur populations. In addition, it also established that T. geei is monophyletic but revealed possible hybridization with capped langur, T. pileatus, in the wild. It is hoped that these findings would result in a more scientific approach towards managing the fragmented populations of this enigmatic species.
Mitochondrial Genome Sequences Effectively Reveal the Phylogeny of Hylobates Gibbons
PLOS One, 2010
Background: Uniquely among hominoids, gibbons exist as multiple geographically contiguous taxa exhibiting distinctive behavioral, morphological, and karyotypic characteristics. However, our understanding of the evolutionary relationships of the various gibbons, especially among Hylobates species, is still limited because previous studies used limited taxon sampling or short mitochondrial DNA (mtDNA) sequences. Here we use mtDNA genome sequences to reconstruct gibbon phylogenetic relationships and reveal the pattern and timing of divergence events in gibbon evolutionary history.
Genetic isolation of populations is a potent force that helps shape the course of evolution. However, small populations in isolation, especially in fragmented landscapes, are known to lose genetic variability, suffer from inbreeding depression and become genetically differentiated among themselves. In this study, we assessed the genetic diversity of lion-tailed macaques (Macaca silenus) inhabiting the fragmented landscape of Anamalai hills and examined the genetic structure of the species across its distributional range in the Western Ghats. We sequenced around 900 bases of DNA covering two mitochondrial regions– hypervariable region-I and partial mitochondrial cytochrome b–from individuals sampled both from wild and captivity, constructed and dated phylogenetic trees. We found that the lion-tailed macaque troops in the isolated forest patches in Anamalai hills have depleted mitochondrial DNA diversity compared to troops in larger and continuous forests. Our results also revealed an ancient divergence in the lion-tailed macaque into two distinct populations across the Palghat gap, dating to 2.11 million years ago. In light of our findings, we make a few suggestions on the management of wild and captive populations.