Search results for "Lineage"
showing 10 items of 331 documents
Phylogeography of Ptychadena mascareniensis suggests transoceanic dispersal in a widespread African-Malagasy frog lineage
2004
Aim The Mascarene ridged frog, Ptychadena mascareniensis, is the only African amphibian species thought to occur on Madagascar and on the Seychelles and also Mascarene islands. We explored its phylogenetic relationships and intraspecific genetic differentiation to contribute to the understanding of transoceanic dispersal in amphibians. Methods Fragments of the mitochondrial 16S rRNA gene were sequenced from specimens collected over most of the distribution area of P. mascareniensis, including populations from Madagascar, Mascarenes and Seychelles. Results We identified five deeply divergent clades having pairwise divergences >5%, which probably all represent cryptic species in a P. mascaren…
A Unique Group of Virus-Related, Genome-Integrating Elements Found Solely in the Bacterial Family Thermaceae and the Archaeal Family Halobacteriaceae
2010
ABSTRACT Viruses SH1 and P23-77, infecting archaeal Haloarcula species and bacterial Thermus species, respectively, were recently designated to form a novel viral lineage. In this study, the lineage is expanded to archaeal Halomicrobium and bacterial Meiothermus species by analysis of five genome-integrated elements that share the core genes with these viruses.
Biomolecular study of the human remains from tomb 5859 in the Etruscan necropolis of Monterozzi Tarquinia (Vitarbo, Italy)
2004
Abstract Archaeological excavation in an Etruscan room tomb, from the Monterozzi necropolis in Tarquinia led to the recovery of four individuals. It was hypothesized that they could be members of a single family group. As both archaeological data and classical anthropological analysis provided little information in this direction, ancient DNA (aDNA) was extracted from bone and tooth fragments of the individuals. For each subject HVR-I of the mitochondrial DNA (mtDNA) was cloned and sequenced. To identify the sex of the individuals, amelogenine and SRY genes were analysed. Short tandem repeat (STR) characterization was also performed. DNA studies were preceded by the evaluation of amino acid…
Reference set of Mycobacterium tuberculosis clinical strains: A tool for research and product development
2018
TheMycobacterium tuberculosiscomplex (MTBC) causes tuberculosis (TB) in humans and various other mammals. The human-adapted members of the MTBC comprise seven phylogenetic lineages that differ in their geographical distribution. There is growing evidence that this phylogenetic diversity modulates the outcome of TB infection and disease. For decades, TB research and development has focused on the two canonical MTBC reference strains H37Rv and Erdman, both of which belong to Lineage 4. Relying on only a few laboratory-adapted strains can be misleading as study results might not be directly transferrable to clinical settings where patients are infected with a diverse array of strains, includin…
When do different C4 leaf anatomies indicate independent C4 origins? Parallel evolution of C4 leaf types in Camphorosmeae (Chenopodiaceae).
2014
Broad-scale phylogenetic studies give first insights in numbers, relationships, and ages of C 4 lineages. They are, however, generally limited to a model that treats the evolution of the complex C4 syndrome in different lineages as a directly comparable process. Here, we use a resolved and well-sampled phylogenetic tree of Camphorosmeae, based on three chloroplast and one nuclear marker and on leaf anatomical traits to infer a more detailed picture of C4 leaftype evolution in this lineage. Our ancestral character state reconstructions allowed two scenarios: (i) Sedobassia is a derived C3/C4 intermediate, implying two independent gains of C4 in Bassia and Camphorosma; or (ii) Sedobassia is a…
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ?accidental cell death' (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. "Regulated cell death" (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to…
In silico exploration of Mycobacterium tuberculosis metabolic networks shows host-associated convergent fluxomic phenotypes
2022
This article belongs to the Special Issue Computational Approaches for the Study of Biomolecular Networks
Human stem cells from single blastomeres reveal pathways of embryonic or trophoblast fate specification.
2015
Mechanisms of initial cell fate decisions differ among species. To gain insights into lineage allocation in humans, we derived ten human embryonic stem cell lines (designated UCSFB1-10) from single blastomeres of four 8-cell embryos and one 12-cell embryo from a single couple. Compared with numerous conventional lines from blastocysts, they had unique gene expression and DNA methylation patterns that were, in part, indicative of trophoblast competence. At a transcriptional level, UCSFB lines from different embryos were often more closely related than those from the same embryo. As predicted by the transcriptomic data, immunolocalization of EOMES, T brachyury, GDF15 and active β-catenin reve…
Phylogeny of Salicornioideae (Chenopodiaceae): Diversification, biogeography, and evolutionary trends in leaf and flower morphology
2006
Chenopodiaceae-Salicomioideae (14-16 gen./c. 90 spp.) are distributed worldwide in coastal and inland saline habitats. Most of them are easy to recognize by their succulent-articulated stem with strongly reduced leaves and by flowers aggregated in dense, thick spike-shaped thyrses. ITS and the atpB-rbcL spacer were sequenced for 67 species representing 14 genera of Salicomioideae and analysed with maximum parsimony and maximum likelihood, a fossil-calibrated molecular clock using the penalized likelihood method, and lineage through time plots. The evolution of stem, leaf, and flower morphology was traced using MacClade. Both molecular markers indicate that the monophyletic Salicomioideae or…
Zum Ursprung der Hominidae
1981
A fundamental problem of hominisation is the branching of the human lineage leading to the genusHomo from other hominoids. At present discussed hypotheses of a Miocene separation of the pongid and hominid lineage are described under consideration of numerous new fossils from Europe, Asia and Africa. Of special interest is the possibility of an adhominisation of the genusAustralopithecus (includingA. afarensis).