Search results for "phylogeny"
showing 10 items of 1398 documents
Phylogenetic reconstruction of the yeast genus Kluyveromyces: restriction map analysis of the 5.8S rRNA gene and the two ribosomal internal transcrib…
1998
Summary We have constructed restriction site maps of the 5.8S rRNA gene and the two ITS regions in 60 strains of Kluyveromyces genus. We test the value of this region as a phylogenetic indicator, and its possible use as a fast and easy method to identify species of this genus. Despite some minor incongruences, our results are in good agreement with previous phylogenetic reconstructions based on the 18S rRNA gene sequencing (Cai et al., 1996; James et al., 1997). A highly significant monophyletic group was formed by K. lactis, K. marxianus, K. aestuarii, K. dobzhanskii and K. wickerhamii, which should be considered the true Kluyveromyces genus. The other species of the genus were grouped wit…
Is activated hemocyanin instead of phenoloxidase involved in immune response in woodlice?
2008
In the Common woodlouse Porcellio scaber (Crustacea: Isopoda: Oniscidea), experimental immune challenge did not induce the expression of pro-phenoloxidase that, in most other invertebrates studied thus far, can be activated into phenoloxidase via an activation cascade upon immune challenge. Instead, Porcellio hemocyanin proved to exhibit catecholoxidase activity upon activation. However, none of the activating factors known from other invertebrates other than SDS-treatment resulted in activation of hemocyanin into a functional phenoloxidase in vitro. The distinct characteristics of isopod hemocyanin are reflected by the quaternary structure of the hemocyanin dodecamers that differs from tha…
The RNA-binding protein ELAV regulates Hox RNA processing, expression and function within the Drosophila nervous system
2014
The regulated head-to-tail expression of Hox genes provides a coordinate system for the activation of specific programmes of cell differentiation according to axial level. Recent work indicates that Hox expression can be regulated via RNA processing but the underlying mechanisms and biological significance of this form of regulation remain poorly understood. Here we explore these issues within the developing Drosophila central nervous system (CNS). We show that the pan-neural RNA-binding protein (RBP) ELAV (Hu antigen) regulates the RNA processing patterns of the Hox gene Ultrabithorax (Ubx) within the embryonic CNS. Using a combination of biochemical, genetic and imaging approaches we demo…
An organizing region in metamorphosing hydrozoan planula larvae--stimulation of axis formation in both larval and in adult tissue.
2010
A novel wingless gene was isolated from the marine colonial hydroid Hydractinia echinata. Alignments and Bayesian inference analysis clearly assign the gene to the Wnt5A group. In line with data found for the brachyury ortholog of Hydractinia, He-wnt5A is expressed during metamorphosis in the posterior tip of the spindle-shaped planula larva, suggesting that the tip functions as a putative organizer during metamorphosis. Additionally, the outermost cells of the posterior tip are omitted from apoptosis during metamorphosis. In order to investigate this putative organizer function, we transplanted the posterior tip of metamorphosing animals into non-induced larvae and into primary polyps 24 h…
Phylogenetic generic classification of parmelioid lichens (Parmeliaceae, Ascomycota) based on molecular, morphological and chemical evidence
2010
WOS: 000285566000008
Comparative genomic and phylogenetic analyses of gammaproteobacterial glg genes traced the origin of the Escherichia coli glycogen glgBXCAP operon to…
2015
© 2015 Almagro et al. Production of branched α-glucan, glycogen-like polymers is widely spread in the Bacteria domain. The glycogen pathway of synthesis and degradation has been fairly well characterized in the model enterobacterial species Escherichia coli (order Enterobacteriales, class Gammaproteobacteria), in which the cognate genes (branching enzyme glgB, debranching enzyme glgX, ADP-glucose pyrophosphorylase glgC, glycogen synthase glgA, and glycogen phosphorylase glgP) are clustered in a glgBXCAP operon arrangement. However, the evolutionary origin of this particular arrangement and of its constituent genes is unknown. Here, by using 265 complete gammaproteobacterial genomes we have …
Population dynamic of the extinct European aurochs: genetic evidence of a north-south differentiation pattern and no evidence of post-glacial expansi…
2010
International audience; Abstract Background The aurochs ( Bos primigenius ) was a large bovine that ranged over almost the entirety of the Eurasian continent and North Africa. It is the wild ancestor of the modern cattle ( Bos taurus ), and went extinct in 1627 probably as a consequence of human hunting and the progressive reduction of its habitat. To investigate in detail the genetic history of this species and to compare the population dynamics in different European areas, we analysed Bos primigenius remains from various sites across Italy. Results Fourteen samples provided ancient DNA fragments from the mitochondrial hypervariable region. Our data, jointly analysed with previously publis…
A new baseline for fascioliasis in Venezuela: lymnaeid vectors ascertained by DNA sequencing and analysis of their relationships with human and anima…
2011
Abstract Background Human and animal fascioliasis poses serious public health problems in South America. In Venezuela, livestock infection represents an important veterinary problem whereas there appear to be few human cases reported, most of which are passively detected in health centres. However, results of recent surveys suggest that the situation may be underestimated in particular areas. To obtain a baseline for future fascioliasis assessment, studies were undertaken by means of rDNA ITS-2 and ITS-1 and mtDNA cox 1 sequencing to clarify the specific status of Venezuelan lymnaeids, their geographical distribution and fascioliasis transmission capacity, by comparison with other American …
Characterization of an isoproturon mineralizing bacterial culture enriched from a French agricultural soil.
2009
The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralized by a bacterial culture isolated from an agricultural soil regularly exposed to IPU. Molecular analysis of the bacterial culture by DNA fingerprinting, cloning and sequencing of the 16S rRNA genes revealed that it consisted of six different members among whom the dominant was related to Sphingomonas sp. Six bacterial strains belonging to genera Ancylobacter, Pseudomonas, Stenotrophomonas, Methylobacterium, Variovorax and Agrobacterium were isolated from the IPU-degrading culture. None of these were able to degrade IPU in pure culture and only the intact culture sustained th…
A legacy of contrasting spatial genetic structure on either side of the Atlantic-Mediterranean transition zone in a marine protist
2012
The mechanisms that underpin the varied spatial genetic structures exhibited by free-living marine microorganisms remain controversial, with most studies emphasizing a high dispersal capability that should redistribute genetic diversity in contrast to most macroorganisms whose populations often retain a genetic signature of demographic response to historic climate fluctuations. We quantified the European phylogeographic structure of the marine flagellate Oxyrrhis marina and found a marked difference in spatial genetic structure, population demography, and genetic diversity between the northwest Atlantic and Mediterranean Sea that reflects the persistent separation of these regions as well …