Search results for " rRNA"

Vertical stratification of bacteria and archaea in sediments of a small boreal humic lake

2019

ABSTRACT Although sediments of small boreal humic lakes are important carbon stores and greenhouse gas sources, the composition and structuring mechanisms of their microbial communities have remained understudied. We analyzed the vertical profiles of microbial biomass indicators (PLFAs, DNA and RNA) and the bacterial and archaeal community composition (sequencing of 16S rRNA gene amplicons and qPCR of mcrA) in sediment cores collected from a typical small boreal lake. While microbial biomass decreased with sediment depth, viable microbes (RNA and PLFA) were present all through the profiles. The vertical stratification patterns of the bacterial and archaeal communities resembled those in mar…

Myxobolus albin. sp. (Myxozoa) from the Gills of the Common GobyPomatoschistus micropsKrøyer (Teleostei: Gobiidae)

2009

A recent investigation into the myxozoan fauna of common gobies, Pomatoschistus microps, from the Forth Estuary in Scotland, revealed numerous myxosporean cysts within the gill cartilage. They were composed of polysporous plasmodia containing myxobolid spores that were morphologically different from the other known species of Myxobolus and from the myxosporeans previously recorded from this host (i.e. the ceratomyxid Ellipsomyxa gobii, infecting the gall bladder, and the kudoid Kudoa camarguensis, infecting the muscle tissues). Spores were ovoid, 9.4 x 9.1 microm with a thickness of 6.6 microm, with two pyriform polar capsules, the polar filaments of which had four to five turns. Molecular …

High-throughput sequencing of the 16S rRNA gene to analyze the gut microbiome in juvenile and adult tropical gar (Atractosteus tropicus)

2020

Tropical gar (Atractosteus tropicus) is freshwater and estuarine fish, inhabiting the Earth since the Mesozoic era and undergoing limited physiological variation ever since. Besides its recognized cultural and scientific relevance, the species has seen remarkable growth in its economic impact due to pisciculture. In this study, we present the first report of the whole taxonomic composition of microbial communities in gut contents in juveniles and adults of A. tropicus, by sex and origin (wild and cultivated). For this study, 508 genera were identified, with the most and least abundant being Cetobacterium and Paludibacter, respectively. Fusobacteria, Proteobacteria, Firmicutes, and Bacteroid…

Intraspecific and within-isolate sequence variation in the ITS rRNA gene region of Pythium mercuriale sp. nov. (Pythiaceae)

2008

Belbahri, Lassaad et al.

Evidence for a novel cytoplasmic processing event in ribosome maturation in the sea urchin Paracentrotus lividus

2010

In this work, we demonstrate the existence of a cytoplasmic processing step, never before described, involving both the pre-ribosomal subunits in the sea urchin Paracentrotus lividus. Northern-blot hybridization, primer extension, S1 mapping experiments and in situ hybridizations allowed us to demonstrate that cytoplasmic processed particles are successively re-imported into the nucleus, where maturation of their RNAs is completed prior to being exported to the cytoplasm. Our findings lead to the proposal of a new model of ribosome maturation and shuttling. Moreover, preliminary data from our laboratory suggest that the maturation pathway we propose in P. lividus may not be unique to the se…

GENOTYPIC AND PHENOTYPIC DIVERSITY OF LACTOBACILLUS ROSSIAE STRAINS ISOLATED FROM SOURDOUGH

2007

Molecular phylogeny of Malagasy poison frogs, genus Mantella (Anura: Mantellidae): homoplastic evolution of colour pattern in aposematic amphibians

2002

Abstract We studied the evolution of colour pattern in Malagasy poison frogs, genus Mantella , a group of diurnal and toxic frogs endemic to Madagascar. Based on a phylogeny reconstructed using 1130 bp of the mitochondrial 16S rRNA gene, the genus can be divided into five species groups. Within some of these groups, interspecific genetic divergences were very low (1.2–2.8% sequence divergence) while colour patterns were markedly different. In contrast, Mantella madagascariensis and M . baroni , two species which show extremely similar dorsal coloration patterns, were not included in the same clade. This conclusion was supported by high bootstrap values and by significant rejection of altern…

New contribution to the systematic status of various Mediterranean scorpionfish, as inferred from a mitochondrial DNA sequence.

2014

This study investigated the molecular phylogeny of 6 Mediterranean species of scorpionfish, belonging to the Scorpaenidae and Sebastidae family. Neighbor-Joining and Maximum Parsimony phylogenetic analyse, based on 424 base pairs of partial mitochondrial DNA sequences of the 12S-rRNA gene, revealed 2 main clades. One clade is represented by the Scorpaena genera (with the species S. notata, S. porcus, and S. scrofa) and another clade consists of the genera Helicolenus, Pterois, and Scorpaenodes. The molecular phylogeny showed that the Scorpaenodes genus (sub-family Scorpaeninae) is found within the clade of the species belonging to the other two sub-families (Pteroninae and Sebastinae). This…

A round trip to the desert: In situ nanopore sequencing informs targeted bioprospecting

2021

Bioprospecting expeditions are often performed in remote locations, in order to access previously unexplored samples. Nevertheless, the actual potential of those samples is only assessed once scientists are back in the laboratory, where a time-consuming screening must take place. This work evaluates the suitability of using Nanopore sequencing during a journey to the Tabernas Desert (Spain) for forecasting the potential of specific samples in terms of bacterial diversity and prevalence of radiation- and desiccation-resistant taxa, which were the target of the bioprospecting activities. Samples collected during the first day were analyzed through 16S rRNA gene sequencing using a mobile labor…

Microbiota Variation Across Life Stages of European Field-Caught Anopheles atroparvus and During Laboratory Colonization: New Insights for Malaria Re…

2021

The potential use of bacteria for developing novel vector control approaches has awakened new interests in the study of the microbiota associated with vector species. To set a baseline for future malaria research, a high-throughput sequencing of the bacterial 16S ribosomal gene V3-V4 region was used to profile the microbiota associated with late-instar larvae, newly emerged females, and wild-caught females of a sylvan Anopheles atroparvus population from a former malaria transmission area of Spain. Field-acquired microbiota was then assessed in non-blood-fed laboratory-reared females from the second, sixth, and 10th generations. Diversity analyses revealed that bacterial communities varied …