Search results for "dea"

Globacrochordiceras gen. nov. (Acrochordiceratidae, late Early Triassic) and its significance for stress-induced evolutionary jumps in ammonoid linea…

2013

<i>Globacrochordiceras transpacificum</i> gen. et sp. nov. is an ammonoid (Ammonoidea, Cephalopoda) with a shell characterized by plicate ribbing (rounded and undulating ribs strengthening on the venter without interruption), increasing involution through ontogeny, overhanging and deep umbilical wall, absence of tuberculation, subtriangular whorl section, globose adult shape with a closed umbilicus followed by an abrupt egressive coiling, and a subammonitic adult suture line. This new taxon occurs in Nevada (USA) and in Guangxi (South China). It has its typical occurrence within the <i>Neopopanoceras haugi</i> Zone of late Spathian age (Early Triassic). The plicate r…

Chloroplast genomes of Rubiaceae: Comparative genomics and molecular phylogeny in subfamily Ixoroideae.

2020

In Rubiaceae phylogenetics, the number of markers often proved a limitation with authors failing to provide well-supported trees at tribal and generic levels. A robust phylogeny is a prerequisite to study the evolutionary patterns of traits at different taxonomic levels. Advances in next-generation sequencing technologies have revolutionized biology by providing, at reduced cost, huge amounts of data for an increased number of species. Due to their highly conserved structure, generally recombination-free, and mostly uniparental inheritance, chloroplast DNA sequences have long been used as choice markers for plant phylogeny reconstruction. The main objectives of this study are: 1) to gain in…

Parallel diversifications of Cremastosperma and mosannona (annonaceae), tropical rainforest trees tracking neogene upheaval of South America

2018

Much of the immense present day biological diversity of Neotropical rainforests originated from the Miocene onwards, a period of geological and ecological upheaval in South America. We assess the impact of the Andean orogeny, drainage of Lake Pebas and closure of the Panama isthmus on two clades of tropical trees ( Cremastosperma , ca 31 spp.; and Mosannona , ca 14 spp.; both Annonaceae). Phylogenetic inference revealed similar patterns of geographically restricted clades and molecular dating showed diversifications in the different areas occurred in parallel, with timing consistent with Andean vicariance and Central American geodispersal. Ecological niche modelling approaches show phyloge…

Inter- and intraspecific hypervariability in interstitial telomeric-like repeats (TTTAGGG)n in Anacyclus (Asteraceae).

2017

BACKGROUND AND AIMS: Interstitial telomeric repeat (ITR) sites, consisting of tandem repeats of telomeric motifs localized at intrachromosomal sites, have been reported in a few unrelated organisms including plants. However, the causes for the occurrence of ITRs outside of the chromosomal termini are not fully understood. One possible explanation are the chromosomal rearrangements involving telomeric sites, which could also affect the location of other structural genome elements, such as the 45S rDNA. Taking advantage of the high dynamism in 45S rDNA loci previously found in Anacyclus (Asteraceae, Anthemideae), the occurrence and patterns of variation of ITRs were explored in this genus wit…

The chaperone-like protein Cdc48 regulates ubiquitin-proteasome system in plants.

2021

The degradation of misfolded proteins is mainly mediated by the ubiquitin-proteasome system (UPS). UPS can be assisted by the protein Cdc48 but the relationship between UPS and Cdc48 in plants has been poorly investigated. Here, we analyzed the regulation of UPS by Cdc48 in tobacco thanks to two independent cell lines overexpressing Cdc48 constitutively and plant leaves overexpressing Cdc48 transiently. In the cell lines, the accumulation of ubiquitinated proteins was affected both quantitatively and qualitatively and the amount of proteasomal subunits was modified, while proteolytic activities were unchanged. Similarly, the over-expression of Cdc48 in planta impacted the accumulation of ub…

Evolutionary relationships between digeneans of the family Brachycladiidae Odhner, 1905 and their marine mammal hosts: A cophylogenetic study.

2016

Cophylogenetic studies examine the congruence between host and parasite phylogenies. There are few studies that quantify the relative contribution of coevolutionary events, i.e. duplication, loss, failure-to-diverge, host-switching and spreading in trophically-transmitted parasites at the marine realm. We addressed this issue in the Brachycladiidae, a cosmopolitan digenean family specific to marine mammals. We used, for the first time, distance-based and event-based methods to explicitly test the coevolutionary events that have shaped the current brachycladiid-marine mammal associations. Parasite phylogeny was constructed using mtDNA ND3 sequences of nine brachycladiid species, and host phy…

Integrative taxonomy of root aphid parasitoids from the genus Paralipsis (Hymenoptera, Braconidae, Aphidiinae) with description of new species

2019

Species from the genus Paralipsis are obligatory endoparasitoids of root aphids in the Palaearctic. It is known that these species are broadly distributed, parasitizing various aphid hosts and showing great biological and ecological diversity. On the other hand, this group of endoparasitoids is understudied and was thought to be represented by a single species in Europe, viz., Paralipsisenervis (Nees). However, recent description of two new species indicated the possibility of cryptic speciation and recognition of additional Paralipsis species in Europe. In this research, Paralipsis specimens collected during the last 60 years from eight European countries, as well as one sample from Morocc…

Evolutionary diversification of type-2 HDAC structure, function and regulation in Nicotiana tabacum

2018

Ministère de l'Education Nationale et de la Recherche ; Conseil Régional de Bourgogne (PARI AGRALE8) ; Association pour la Recherche sur les Nicotianacées ; Conseil Régional de Bourgogne; International audience; Type-2 HDACs (HD2s) are plant-specific histone deacetylases that play diverse roles during development and in responses to biotic and abiotic stresses. In this study we characterized the six tobacco genes encoding HD2s that mainly differ by the presence or the absence of a typical zinc finger in their C-terminal part. Of particular interest, these HD2 genes exhibit a highly conserved intron/exon structure. We then further investigated the phylogenetic relationships among the HD2 gen…

Morphological and molecular analysis of Henricia Gray, 1840 (Asteroidea: Echinodermata) from the Northern Atlantic Ocean

2017

The evolution of dwarf shrubs in alpine environments: a case study ofAlchemillain Africa

2015

BACKGROUND AND AIMS Alpine and arctic environments worldwide, including high mountains, are dominated by short-stature woody plants (dwarf shrubs). This conspicuous life form asserts considerable influence on local environmental conditions above the treeline, creating its own microhabitat. This study reconstructs the evolution of dwarf shrubs in Alchemilla in the African tropical alpine environment, where they represent one of the largest clades and are among the most common and abundant plants. METHODS Different phylogenetic inference methods were used with plastid and nuclear DNA sequence markers, molecular dating (BEAST and RelTime), analyses of diversification rate shifts (MEDUSA and BA…