Search results for "Reticulate"

Introgression of mitochondrial DNA among Myodes voles: consequences for energetics?

2011

Abstract Background Introgression of mitochondrial DNA (mtDNA) is among the most frequently described cases of reticulate evolution. The tendency of mtDNA to cross interspecific barriers is somewhat counter-intuitive considering the key function of enzymes that it encodes in the oxidative-phosphorylation process, which could give rise to hybrid dysfunction. How mtDNA reticulation affects the evolution of metabolic functions is, however, uncertain. Here we investigated how morpho-physiological traits vary in natural populations of a common rodent (the bank vole, Myodes glareolus) and whether this variation could be associated with mtDNA introgression. First, we confirmed that M. glareolus ha…

Morphological observations on the reproductive structures of Ambrosina (Araceae), a Mediterranean endemic monotypic genus

2017

This research was carried out to better define the pollen, fruit and seed morphology of Ambrosina bassii , the only species of this rare Mediterranean endemic genus. Pollen traits were already known, but here we investigated on their variability in distant populations and in different morphotypes (‘varieties’). Fruit and seed traits were almost unknown, also because of the rarity of fruit-set in this species. The surface features of pollen, fruit and seed, as well as length, width and length/width ratio, were analysed by means of scanning electron microscopy (SEM). Comparative observations were made also on Arisarum vulgare , since Arisarum is the closest genus. The principal component anal…

Mitochondrial introgression suggests extensive ancestral hybridization events among Saccharomyces species.

2017

Horizontal gene transfer (HGT) in eukaryotic plastids and mitochondrial genomes is common, and plays an important role in organism evolution. In yeasts, recent mitochondrial HGT has been suggested between S. cerevisiae and S. paradoxus. However, few strains have been explored given the lack of accurate mitochondrial genome annotations. Mitochondrial genome sequences are important to understand how frequent these introgressions occur, and their role in cytonuclear incompatibilities and fitness. Indeed, most of the Bateson-Dobzhansky-Muller genetic incompatibilities described in yeasts are driven by cytonuclear incompatibilities. We herein explored the mitochondrial inheritance of several wor…

Two brothers with confluent and reticulated papillomatosis.

2016

Micromorphological observations on leaf and pollen ofCapparisL. sect.Capparis(Capparaceae)

2004

Sect. Capparis is represented by a single species, Capparis spinosa L., divided into several intraspecific taxa showing plesiomorphic features and disjunct distributions in the Old World. Leaf surface and pollen features were investigated in the whole group by SEM and light microscope observations. The section is characterized by simple hairs, a reticulate to undulate cuticle, anomocytic stomata surrounded by a peristomal rim, and trizonocolporate, prolate pollen grains. The characteristics of the indumentum appear constant, while the studied taxa are fairly differentiated with respect to cuticular patterns and dimensions of the stomata, and show slight differences in pollen size and exine …

Effect of magnetic fields on seedling growth and cyto-morphogenesis inSinapis albaL.

2001

Abstract The magnetic treatment presented in this study could be included among cultivation procedures aimed at a better utilisation of plant species. The treatment enhances seedling growth (expressed in fresh weight or in length of the hypocotyl) stimulates morphogenic events (premature differentiation of the reticulate xylem elements, increased wall thickness, reduction of the xylem diameter, increase of acid phosphatases) and renders the seedling batches more homogeneous. Our study demonstrates that exposure to weak (30 mT) magnetic fields for short periods (15, 30, 60 seconds) stimulates seedling growth.

Study of the Evolutionary Relationships among Limonium Species (Plumbaginaceae) Using Nuclear and Cytoplasmic Molecular Markers

2000

The genus Limonium, due to the patchiness of the natural habitats of its species as well as the high frequency of hybridization and polyploidy and the possibility of reproduction by apomixis, provides an example of all the principal mechanisms of rapid speciation of plants. As an initial study of evolution in this genus, we have analyzed intra- and interspecific variability in 17 species from section Limonium, the largest in the genus, based on RFLPs of cpDNA and nuclear rDNA ITS sequences. In the cpDNA analysis, 21 restriction enzymes were used, resulting in 779 fragments, 490 of which were variable and 339 parsimony informative. L. furfuraceum exhibited two relatively divergent cpDNA hapl…

Investigating a simplified method for noninvasive genetic sampling in East African mammals using silica dried scat swabs

2020

Abstract Swabbing scat has proved to be an effective noninvasive method to collect DNA from mammals in the field. Previously, this method has relied on preservative liquids or freezing to preserve the DNA collected on swabs. In this study, we determine the effectiveness of using silica to simply dry the swab in field as an alternative way to prevent DNA degredation. Four species were included in the study; reticulated giraffe, impala, fringe‐eared oryx, and lion. Swabs were taken at multiple time points for giraffe and impala scat samples, with the lion and oryx sampled opportunistically. Mitochondrial DNA was successfully amplified and sequenced from scat swabs from all species; however, e…

Phylogenetics of Anthyllis (Leguminosae: Papilionoideae: Loteae): Partial incongruence between nuclear and plastid markers, a long branch problem and…

2010

Abstract Phylogenetic relationships in the genus Anthyllis (Leguminosae: Papilionoideae: Loteae) were investigated using data from the nuclear ribosomal internal transcribed spacer regions (ITS) and three plastid regions (psbA–trnH intergenic spacer, petB–petD region and rps16 intron). Bayesian and maximum parsimony (MP) analysis of a concatenated plastid dataset recovered well-resolved trees that are topologically similar, with many clades supported by unique indels. MP and Bayesian analyses of the ITS sequence data recovered trees that have several well-supported topological differences, both among analyses, and to trees inferred from the plastid data. The most substantial of these concer…

Reticulation or divergence: the origin of a rare serpentine endemic assessed with chloroplast, nuclear and RAPD markers

2002

Species of Armeria from the southern part of the Iberian Peninsula have been postulated to undergo extensive reticulate evolution based on ITS sequences as well as morphometric, eco-geographical evidence and crossing experiments. The hypothesis that a rare serpentine endemic (A. villosa subsp. carratracensis) originated from a cross between another serpentine tolerant endemic (A. colorata) and a widespread limestone species (A. villosa subsp. longiaristata) is tested with molecular markers. Sequences from two chloroplast regions [trnL (UAA)-trnF (GAA) and trnD (GUC)-trnT (GGU)], from nuclear ribosomal DNA (ITS-1 + 5.8S + ITS-2) as well as RAPD data are used. Variation in chloroplast and nuc…