Search results for "phylogenetics"

Evolution of molluscan hemocyanins as deduced from DNA sequencing

2004

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…

Molecular phylogeny of Camphorosmeae (Camphorosmoideae, Chenopodiaceae): Implications for biogeography, evolution of C4-photosynthesis and taxonomy

2011

Camphorosmeae constitute a species-rich tribe of Chenopodiaceae-Camphorosmoideae that consists mostly of subshrubs and annuals, distributed in steppes and semi-deserts of Australia, Eurasia, North Africa, southern Africa and North America. We study (1) the relationships of Camphorosmeae to major lineages of the closely related Salsoloideae and (2) the diversification of the tribe with focus on the non-Australian members using sequence variation of five different markers (rbcL gene, ndhF gene, atpB-rbcL spacer, psbB-psbH spacer, ITS) and morphological characters. The cpDNA analyses revealed six early-branching lineages in Camphorosmoideae/Salsoloideae (Camphorosmeae, Salsoleae s.str., Caroxy…

A multi-locus inference of the evolutionary diversification of extant flamingos (Phoenicopteridae).

2014

9 pages; International audience; BACKGROUND: Modern flamingos (Phoenicopteridae) occupy a highly specialized ecology unique among birds and represent a potentially powerful model system for informing the mechanisms by which a lineage of birds adapts and radiates. However, despite a rich fossil record and well-studied feeding morphology, molecular investigations of the evolutionary progression among modern flamingos have been limited. Here, using three mitochondrial (mtDNA) markers, we present the first DNA sequence-based study of population genetic variation in the widely distributed Chilean Flamingo and, using two mtDNA and 10 nuclear (nDNA) markers, recover the species tree and divergence…

Archaea in boreal Swedish lakes are diverse, dominated by Woesearchaeota and follow deterministic community assembly

2020

Despite their key role in biogeochemical processes, particularly the methane cycle, archaea are widely underrepresented in molecular surveys because of their lower abundance compared to bacteria and eukaryotes. Here, we use parallel high‐resolution small subunit rRNA gene sequencing to explore archaeal diversity in 109 Swedish lakes and correlate archaeal community assembly mechanisms to large‐scale latitudinal, climatic (nemoral to arctic), and nutrient (oligotrophic to eutrophic) gradients. Sequencing with universal primers showed the contribution of archaea was on average 0.8% but increased up to 1.5% of the three domains in forest lakes. Archaea‐specific sequencing revealed that freshwa…

The Cryptocercus punctulatus species complex (Dictyoptera: Cryptocercidae) in the eastern United States: comparison of cuticular hydrocarbons, chromo…

2008

1055-7903; The goal of the current study was to determine if cuticular hydrocarbons could be used to empirically delimit taxa within the Cryptocercus punctulatus species complex in the eastern United States. Cockroaches were collected from rotting logs in 22 locations across four states. Hydrocarbon phenotypes and two mitochondrial (16S and COII) genes and one nuclear (ITS2) gene were independently analyzed to determine their relationship with chromosome number. Five distinct hydrocarbon phenotypes were found, but these were only partly congruent with chromosome number and thus with purported species descriptions. Molecular and cuticular hydrocarbon data each indicate that Cryptocercus with…

Altered cellular magnesium responsiveness to hyperglycemia in hypertensive subjects.

2001

Abstract — — Previous studies by our group have identified ionic aspects of insulin resistance in hypertension, in which cellular responses to insulin were influenced by the basal intracellular ionic environment—the lower the cytosolic free magnesium (Mg i ), the less Mg i increased following insulin stimulation. To investigate whether this ionic insulin resistance represents a more general abnormality of cellular responsiveness in hypertension, we studied Mg i responses to nonhormonal signals such as hyperglycemia (15 mmol/L) and used 31 P-nuclear magnetic resonance (NMR) spectroscopy to measure Mg i in erythrocytes from normal (NL, n=14) and hypertensive (HTN, n=12) subjects before and 3…

Bacteria Associated with Copestylum (Diptera, Syrphidae) Larvae and Their Cactus Host Isolatocereus dumortieri

2011

We describe the gut bacterial diversity inhabiting two saprophagous syrphids and their breeding substrate (decayed tissues of the columnar cactus Isolatocereus dumortieri). We analyzed the gut microbiota of Copestylum latum (scooping larvae that feed on decayed cactus tissues) and Copestylum limbipenne (whose larvae can also feed on semiliquid tissues) using molecular techniques. DNA was extracted from larval guts and cactus tissues. The V1-V3 region of the 16S rRNA genes was amplified and sequenced. A total of 31079 sequences were obtained. The main findings are: C. limbipenne is dominated by several Enterobacteriaceae, including putative nitrogen-fixing genera and pectinolitic species and…

Sequence and evolution of a hexamerin from the ant Camponotus festinatus.

2000

In the ant Camponotus festinatus, two different hexamerins accumulate stage-specifically during the late larval period and at various times in adults. These hexamerins serve as storage proteins and play important roles in brood nourishment and colony founding. We report an analysis of the cDNA sequence of C. festinatus hexamerin 2 (CfeHex2). The native protein contains 732 amino acids, which are moderately enriched in aromatic amino acids, aspartate and asparagine. Phylogenetic analyses show a close relationship of CfeHex2 to a putative toxin of the braconid wasp, Bracon hebetor. The divergence of Formicidae and Braconidae hexamerins was calculated to have begun 187 MYA, an estimate consist…

Insights into the relationships of Palearctic and Nearctic lymnaeids (Mollusca : Gastropoda) by rDNA ITS-2 sequencing and phylogeny of stagnicoline i…

2003

Fascioliasis by Fasciola hepatica is the vector-borne disease presenting the widest latitudinal, longitudinal and altitudinal distribution known. F. hepatica shows a great adaptation power to new environmental conditions which is the consequence of its own capacities together with the adaptation and colonization abilities of its specific vector hosts, freshwater snails of the family Lymnaeidae. Several lymnaeid species only considered as secondary contributors to the liver fluke transmission have, however, played a very important role in the geographic expansion of this disease. Many of them belong to the so-called "stagnicoline" type group. Stagnicolines have, therefore, a very important a…