RESUMO
The Pecorans (higher ruminants) are believed to have rapidly speciated in the Mid-Eocene, resulting in five distinct extant families: Antilocapridae, Giraffidae, Moschidae, Cervidae, and Bovidae. Due to the rapid radiation, the Pecoran phylogeny has proven difficult to resolve, and 11 of the 15 possible rooted phylogenies describing ancestral relationships among the Antilocapridae, Giraffidae, Cervidae, and Bovidae have each been argued as representations of the true phylogeny. Here we demonstrate that a genome-wide single nucleotide polymorphism (SNP) genotyping platform designed for one species can be used to genotype ancient DNA from an extinct species and DNA from species diverged up to 29 million years ago and that the produced genotypes can be used to resolve the phylogeny for this rapidly radiated infraorder. We used a high-throughput assay with 54,693 SNP loci developed for Bos taurus taurus to rapidly genotype 678 individuals representing 61 Pecoran species. We produced a highly resolved phylogeny for this diverse group based upon 40,843 genome-wide SNP, which is five times as many informative characters as have previously been analyzed. We also establish a method to amplify and screen genomic information from extinct species, and place Bison priscus within the Bovidae. The quality of genotype calls and the placement of samples within a well-supported phylogeny may provide an important test for validating the fidelity and integrity of ancient samples. Finally, we constructed a phylogenomic network to accurately describe the relationships between 48 cattle breeds and facilitate inferences concerning the history of domestication and breed formation.
Assuntos
Evolução Biológica , Extinção Biológica , Genômica/métodos , Filogenia , Ruminantes/genética , Animais , Cruzamento , Bovinos , DNA/análise , DNA/genética , Fósseis , GenótipoRESUMO
A total of 114 captive elephants (6 Asian; 108 African) from 43 private institutions or North American zoos accredited by the Association of Zoos and Aquariums were sampled and evaluated to investigate genetic status. Because previous analyses of the captive collection indicated potential cytonuclear dissociation between mitochondrial DNA (mtDNA) sequence and microsatellite nuclear DNA genotype data, we investigated this phenomenon within the captive collection with 2 X-linked genes (BGN and PHKA2) and 1 Y-linked gene (AMELY). These data reveal that individuals with forest-derived elephant mtDNA lineages carried only savannah elephant nuclear gene haplotypes. These results are concordant with a previous study of wild populations sampled across Africa, indicating that cytonuclear genomic dissociation was captured in the founders of the North American African elephant collection. These results are important for resolving questions that can potentially impact future management and breeding programs related to the collection.
Assuntos
Animais de Zoológico/genética , Conservação dos Recursos Naturais/métodos , DNA Mitocondrial/genética , Elefantes/genética , Evolução Molecular , Variação Genética , Genética Populacional , Repetições de Microssatélites/genética , Animais , Sequência de Bases , Biglicano , Análise por Conglomerados , Proteínas da Matriz Extracelular/genética , Haplótipos/genética , Funções Verossimilhança , Modelos Genéticos , Dados de Sequência Molecular , Filogenia , Proteoglicanas/genética , Análise de Sequência de DNARESUMO
This study presents the first detailed morphometric measurements of wild caught black-and-white ruffed lemurs (Varecia variegata) from the eastern rainforests of Madagascar and aims to quantify the morphological variation present throughout their recognized range. One hundred and forty-four adult and juvenile individuals from 15 sites were sampled for 20 cranial, dental and postcranial morphometric and body mass measurements. Data were collected from an equal number of male and female individuals sampled across seasons over a 7-year period (1999-2002, 2004-2006). Results indicate that adult body mass and morphometric measurements varied between sexes across sites; however, the only significant intersexual difference found was that females possessed, on average, longer tails than males. Contrary to previous studies, significant seasonal variation could not be detected in either male or female body mass or testicular volume (i.e., breeding vs. nonbreeding, food-scarce vs. food-abundant seasons). Measurements did, however, vary significantly by site and subspecies, though clinal variation could not explain these differences. The introduced population from Nosy Mangabe exhibited significantly lower body mass and overall body length than all other populations; however, this distinction may not have been attributable to natural variation, and may have instead resulted from the ecologically restrictive habitat (e.g., unusually high lemur population densities, limited food resources, ecological isolation) of this introduced population. Finally, although fore-to-hindlimb, brachium-to-thigh and hindlimb indices were comparable to previous values, forelimb indices calculated here deviate significantly from previous reports, placing V. variegata within the upper range of lemurid taxa. It is currently unknown whether this is an artifact of sampling methods (i.e., live vs. skeletal specimens) or whether this is an avenue that warrants further investigation.
Assuntos
Lemur/anatomia & histologia , Animais , Tamanho Corporal , Dentição , Feminino , Geografia , Madagáscar , Masculino , Dinâmica Populacional , Estações do Ano , Caracteres Sexuais , Crânio/anatomia & histologia , Especificidade da Espécie , Cauda/anatomia & histologia , Testículo/anatomia & histologiaRESUMO
BACKGROUND: A central question in the evolutionary diversification of large, widespread, mobile mammals is how substantial differentiation can arise, particularly in the absence of topographic or habitat barriers to dispersal. All extant giraffes (Giraffa camelopardalis) are currently considered to represent a single species classified into multiple subspecies. However, geographic variation in traits such as pelage pattern is clearly evident across the range in sub-Saharan Africa and abrupt transition zones between different pelage types are typically not associated with extrinsic barriers to gene flow, suggesting reproductive isolation. RESULTS: By analyzing mitochondrial DNA sequences and nuclear microsatellite loci, we show that there are at least six genealogically distinct lineages of giraffe in Africa, with little evidence of interbreeding between them. Some of these lineages appear to be maintained in the absence of contemporary barriers to gene flow, possibly by differences in reproductive timing or pelage-based assortative mating, suggesting that populations usually recognized as subspecies have a long history of reproductive isolation. Further, five of the six putative lineages also contain genetically discrete populations, yielding at least 11 genetically distinct populations. CONCLUSION: Such extreme genetic subdivision within a large vertebrate with high dispersal capabilities is unprecedented and exceeds that of any other large African mammal. Our results have significant implications for giraffe conservation, and imply separate in situ and ex situ management, not only of pelage morphs, but also of local populations.
Assuntos
Artiodáctilos/genética , Variação Genética , Genética Populacional , Animais , Teorema de Bayes , Análise por Conglomerados , DNA Mitocondrial/genética , Evolução Molecular , Frequência do Gene , Haplótipos , Funções Verossimilhança , Repetições de Microssatélites/genética , Fenótipo , Especificidade da EspécieRESUMO
The current range of the red ruffed lemur (Varecia rubra) population is primarily restricted to forests of the Masoala Peninsula on the northeastern coast of Madagascar. Whereas much of the peninsula is protected as Masoala National Park, parts of the forest are at risk from anthropogenic pressures and habitat fragmentation. We sampled 32 individual red ruffed lemur from two sites: Ambatoledama (DAMA), a narrow forest corridor across an area of degraded habitat connecting larger blocks of forest in the northwestern reaches of the park, and Masiaposa (MAS) forest, a largely pristine forest on the lower western side of the peninsula. Population genetic parameters were estimated for these two populations employing 15 microsatellite loci derived from the V. variegata genome. We found that by exceeding the expected heterozygosity at mutation-drift equilibrium, the DAMA population has undergone a recent population bottleneck. Population structure analysis detected individuals harboring genotypic admixture of the DAMA genetic cluster in the MAS population, suggesting a possibility of unilateral gene flow or movement between these populations.
Assuntos
Ecossistema , Variação Genética , Lemuridae/genética , Animais , Demografia , Genótipo , Madagáscar , ÁrvoresRESUMO
The complete mitochondrial DNA (mtDNA) genome of Hubbard's or Zombitse sportive lemur (Lepilemur hubbardorum) was generated by polymerase chain reaction (PCR) amplification, primer-walking sequencing and fragment cloning. Comparative analyses of Hubbard's sportive lemur were conducted with available complete mitochondrial genome sequences from eight other lemur species. The mitochondrial genome of Hubbard's sportive lemur is 16,854 base pairs (bp) and contains 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and one control region. Three rare start codons were found, in which GTG is the start codon for the ATPase 6 subunit gene (ATP), ATC for the NADH dehydrogenase (ND) 2 subunit gene, and ATT for the ND5 subunit gene. In the control region, sequence analysis found one repetitive unit between conserved sequence blocks (CSB)-1 and CSB-2 for L. hubbardorum. Comparative analysis of eight other lemur species showed different repetitive units between and outside of these two blocks. According to the phylogenetic analysis of the 12 heavy-strand encoded protein-coding genes, all nine lemur species representative of four lemuriformes families were monophyletic. This template and the newly designed primers described in this study will allow scientists to generate comparative sequences for all sportive lemurs to validate phylogenetic discrepancies in the genus Lepilemur and to evaluate evolutionary and biogeographic models.
Assuntos
Genoma Mitocondrial , Lemuridae/genética , Animais , Sequência de Bases , DNA Mitocondrial , Masculino , Dados de Sequência Molecular , FilogeniaRESUMO
Decken's sifaka (Propithecus deckeni deckeni) is found between the Mahavavy and Manambolo Rivers, in western Madagascar. Twenty-one polymorphic nuclear microsatellite loci were isolated from genomic DNA derived from a P. d. deckeni, from Tsingy de Bemaraha National Park. Population genetic parameters were estimated on 10 individuals each, sampled from Tsingy de Bemaraha National Park and Tsiombikibo Classified Forests. Significant null alleles were detected in seven loci which were dropped before population genetic parameters were re-estimated and compared to the full marker suite.