Search results for "sister"
showing 10 items of 121 documents
Three intercontinental disjunctions in Papaveraceae subfamily Chelidonioideae: evidence from chloroplast DNA
1995
An RFLP analysis of the chloroplast genome of Papaveraceae subfam. Chelidonioideae resulted in one most parsimonious tree consisting of three monophyletic groups. Each group contains intercontinental disjunct taxa. Whereas Eomecon/Sanguinaria and Stylophorum are examples for the well known E Asian — eastern N American disjunction, the E Asian -C and S American disjunction in Macleaya/Bocconia is rare. The genus Stylophorum in this analysis is paraphyletic. The N American Stylophorum diphyllum is sister group to the Old World members of Stylophorum and Chelidonium. All American representatives of the subfamily possess distinctive morphological features. This might be the result of Tertiary a…
Molecular phylogeny of the Old World representatives of Papaveraceae subfamily Papaveroideae with special emphasis on the genus Meconopsis
1995
The RFLP-analysis of PCR amplified cpDNA fragments of 42 representatives of Papaveraceae subfam. Papaveroideae resulted in six most parsimonious cladograms. The subfamily can be divided into a New World group (Arctomecon, Argentone, Canbya, Romneya and Platystemon) and an Old World group (Meconopsis, Papaver s.l. and Roemeria) containing Stylomecon heterophylla and Papaver californicum as New World taxa. In the Old World group neither Meconopsis nor Papaver are monophyletic. Whereas Meconopsis consists of three clades, Papaver comprises five clades, with Roemeria as sister group to P. sect. Argemonidium and Stylomecon as sister group to P. californicum. Various lines of evidence suggest tha…
NEW DATA ON PALEOZOIC GRYLLOBLATTID INSECTS (NEOPTERA)
2005
Abstract The paraphyletic group Grylloblattida, formerly included in the Protorthoptera sensu lato, is of great importance for the phylogeny of some ‘polyneopterous’ orders, because it is currently assumed to contain the sister groups of modern Plecoptera (stoneflies) and Grylloblattodea. We present new discoveries and new observations and interpretations concerning this crucial assemblage. Lodevopterum angustus new genus and species and Depressopterum minutus new species are described from the Upper Permian of the Lodeve Basin (Herault, France). The ‘Grylloblattida’ from Commentry (Allier, France; Upper Carboniferous) are revised: the family Protoblattinidae Meunier, 1909a is restored afte…
Molecular phylogeny of hyperoliid treefrogs: biogeographic origin of Malagasy and Seychellean taxa and re-analysis of familial paraphyly
2003
Treefrogs of the family Hyperoliidae are distributed in Africa, Madagascar and the Seychelles. In this study, their phylogeny was studied using sequences of fragments of the mitochondrial 16Sand 12SrRNA and cytochrome b genes. The molecular data strongly confirmed monophyly of the subfamily Hyperoliinae but indicated that the genus Leptopelis (subfamily Leptopelinae) is more closely related to species of the African family Astylosternidae. The Seychellean genus Tachycnemis was the sister group of the Malagasy Heterixalus in all molecular analyses; this clade was deeply nested within the Hyperoliinae. A re-evaluation of the morphological data did not contradict the sister group relationships…
The phylogeny of (Gentianaceae) and its colonization of the southern hemisphere as revealed by nuclear and chloroplast DNA sequence variation
2001
Abstract The generic circumscription and infrageneric phylogeny of Gentianella was analysed based on matK and ITS sequence variation. Our results suggested that Gentianella is polyphyletic and should be limited to species with only one nectary per petal lobe. Gentianella in such a circumscription is most closely related to one part of a highly polyphyletic Swertia. within uninectariate Gentianella two major groups could be recognized: 1) northern hemispheric species with vascularized fimbriae at the base of the corolla lobes, and 2) northern hemispheric, South American, and Austrlia/New Zealand species without vascularized fimbriae. When fimbriae are present in this latter group, they are n…
The phylogeny ofPapaver s. l. (Papaveraceae): Polyphyly or monophyly?
1997
An RFLP analysis of the chloroplast genetrnK of 32 species of the generaPapaver, Roemeria, Stylomecon, andMeconopsis leads to the following conclusions: (1) AsianMeconopsis consists of two distinct clades and is paraphyletic in relation toPapaver, Roemeria, Stylomecon, and the W EuropeanMeconopsis cambrica. (2) Sister group relationships ofRoemeria toPapaver sect.Argemonidium and ofStylomecon toPapaver californicum are well-supported. (3)Meconopsis cambrica is nested withinPapaver (incl.Roemeria andStylomecon). The consideration of morphology, geographical distribution and ecology leads to the conclusion thatM. cambrica is best regarded as a member ofMeconopsis, and thatPapaver arose polyph…
Phylogenetic placement of Triaenophora (formerly Scrophulariaceae) with some implications for the phylogeny of Lamiales
2009
Phylogenetic placement of Triaenophora together with Rehmannia were explored with DNA sequence data from five regions (rbcL, ndhF, rps16, trnL-F, nr ITS) in two combined data matrices. One (rbcL, ndhF, rps16) represented a wide sampling across most families of Lamiales. The other data matrix represented two DNA regions partly unalignable across Lamiales (trnL-F, nr ITS) plus rps16, which proved to be variable enough to give resolution at a smaller taxonomic level in Lamiales. Triaenophora rupestris and Rehmannia are sister taxa, composing a strongly supported clade, which is sister to all representative genera of Orobanchaceae. Furthermore, Paulowniaceae and Phrymaceae are next to Orobancha…
The Phylogenetic position of Daubentonia madagascariensis (Gmelin, 1788; primates, Strepsirhini) as revealed by chromosomal analysis
2012
One of the major topics in primate evolution is the phylogenetic position of the bizarre Daubentonia madagascariensis (DMA, aye-aye). The principal points that have been discussed for many decades are whether the aye-aye is: (i) the sister group of primates; (ii) the sister group of strepsirhines; or (iii) the sister group of lemurs. Very little is known about Daubentonia evolution, particularly on the chromosomal background. The present report focuses on the chromosomal history of this species. We used available chromosome painting data as the main source to identify conserved chromosomes, chromosomal segments and syntenic associations that have characterized the aye-aye karyotype. The dat…
Cracking the nut: Geographical adjacency of sister taxa supports vicariance in a polytomic salamander clade in the absence of node support
2008
The urodelan genus Lyciasalamandra, which inhabits a relatively small area along the southern Turkish coast and some Aegean islands, provides an outstanding example of a diverse but phylogenetically unresolved taxon. Molecular trees contain a single basal polytomy that could be either soft or hard. We here use the information of nuclear (allozymes) and mitochondrial (fractions of the 16S rRNA and ATPase genes) datasets in combination with area relationships of lineages to resolve the phylogenetic relationships among Lyciasalamandra species in the absence of sufficient node support. We can show that neither random processes nor introgressive hybridization can be invoked to explain that the m…
Loss of ATM sensitizes against O6-methylguanine triggered apoptosis, SCEs and chromosomal aberrations.
2003
A critical pre-cytotoxic and -apoptotic DNA lesion induced by methylating carcinogens and chemotherapeutic drugs is O6-methylguanine (O6MeG). The mechanism by which O6MeG causes cell death via apoptosis is only partially understood. The current model ascribes a role to DNA replication and mismatch repair, which converts O6MeG into a critical distal lesion (presumably a DNA double-strand break) that is finally responsible for genotoxicity and apoptosis. Here we analysed whether the PI3-like kinase ATM is involved in this process. ATM is a major player in recognizing and signaling DNA breaks, but most reports are limited to ionizing radiation. Comparing mouse ATM knockout fibroblasts (ATM-/-)…