Phylogeny and divergence time estimation of cheilostome bryozoans based on mitochodrial 16S rRNA sequences

2005 ◽  
Vol 50 (12) ◽  
pp. 1205 ◽  
Author(s):  
Jiasheng HAO
Keyword(s):  
16S Rrna ◽  
Divergence Time ◽  
Time Estimation ◽  
Divergence Time Estimation ◽  
Cheilostome Bryozoans ◽  
Rrna Sequences ◽  
16S Rrna Sequences

scholarly journals Out of the Qinghai-Tibetan Plateau (QTP) and rapid radiation across Eurasia for Allium section Daghestanica (Amaryllidaceae)

AoB Plants ◽  
2021 ◽  
Author(s):  
Min-Jie Li ◽  
Huan-Xi Yu ◽  
Xian-Lin Guo ◽  
Xing-Jin He
Keyword(s):  
Evolutionary History ◽  
Divergence Time ◽  
Time Estimation ◽  
Adjacent Region ◽  
Rapid Radiation ◽  
Divergence Time Estimation ◽  
Species Diversification ◽  
The Third ◽  
Evolutionary Line ◽  
History Of

Abstract The disjunctive distribution (Europe-Caucasus-Asia) and species diversification across Eurasia for the genus Allium sect. Daghestanica has fascinating attractions for researchers aiming to understanding the development and history of the modern Eurasia flora. However, no any studies have been carried out to address the evolutionary history of this section. Based on the nrITS and cpDNA fragments (trnL-trnF and rpl32-trnL), the evolutionary history of the third evolutionary line (EL3) of the genus Allium was reconstructed and we further elucidate the evolutionary line of sect. Daghestanica under this background. Our molecular phylogeny recovered two highly supported clades in sect. Daghestanica: the Clade I includes Caucasian-European species and Asian A. maowenense, A. xinlongense and A. carolinianum collected in Qinghai; the Clade II comprises Asian yellowish tepal species, A. chrysanthum, A. chrysocephalum, A. herderianum, A. rude and A. xichuanense. The divergence time estimation and biogeography inference indicated that Asian ancestor located in the QTP and the adjacent region could have migrated to Caucasus and Europe distributions around the Late Miocene and resulted in further divergence and speciation; Asian ancestor underwent the rapid radiation in the QTP and the adjacent region most likely due to the heterogeneous ecology of the QTP resulted from the orogeneses around 4–3 Mya. Our study provides a picture to understand the origin and species diversification across Eurasia for sect. Daghestanica.

scholarly journals Correction to: Bacterial community assemblages in classroom floor dust of 50 public schools in a large city: characterization using 16S rRNA sequences and associations with environmental factors

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ju-Hyeong Park ◽  
Angela R. Lemons ◽  
Jerry Roseman ◽  
Brett J. Green ◽  
Jean M. Cox-Ganser
Keyword(s):  
Public Schools ◽  
Environmental Factors ◽  
Bacterial Community ◽  
16S Rrna ◽  
Large City ◽  
Floor Dust ◽  
Community Assemblages ◽  
Rrna Sequences ◽  
16S Rrna Sequences

An amendment to this paper has been published and can be accessed via the original article.

scholarly journals 16S rRNA sequences reveal uncultured inhabitants of a well-studied thermal community

1990 ◽  
Vol 75 (2-3) ◽  
pp. 105-115 ◽  
Author(s):  
David M. Ward ◽  
Roland Weller ◽  
Mary M. Bateson
Keyword(s):  
16S Rrna ◽  
Rrna Sequences ◽  
16S Rrna Sequences

scholarly journals Divergence and Redundancy of 16S rRNA Sequences in Genomes with Multiple rrn Operons

2004 ◽  
Vol 186 (9) ◽  
pp. 2629-2635 ◽  
Author(s):  
Silvia G. Acinas ◽  
Luisa A. Marcelino ◽  
Vanja Klepac-Ceraj ◽  
Martin F. Polz
Keyword(s):  
16S Rrna ◽  
Thermophilic Bacteria ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Bacterial Genomes ◽  
16S Rrna Sequence ◽  
Thermoanaerobacter Tengcongensis ◽  
Copy Numbers ◽  
Rrna Sequences ◽  
16S Rrna Sequences

ABSTRACT The level of sequence heterogeneity among rrn operons within genomes determines the accuracy of diversity estimation by 16S rRNA-based methods. Furthermore, the occurrence of widespread horizontal gene transfer (HGT) between distantly related rrn operons casts doubt on reconstructions of phylogenetic relationships. For this study, patterns of distribution of rrn copy numbers, interoperonic divergence, and redundancy of 16S rRNA sequences were evaluated. Bacterial genomes display up to 15 operons and operon numbers up to 7 are commonly found, but ∼40% of the organisms analyzed have either one or two operons. Among the Archaea, a single operon appears to dominate and the highest number of operons is five. About 40% of sequences among 380 operons in 76 bacterial genomes with multiple operons were identical to at least one other 16S rRNA sequence in the same genome, and in 38% of the genomes all 16S rRNAs were invariant. For Archaea, the number of identical operons was only 25%, but only five genomes with 21 operons are currently available. These considerations suggest an upper bound of roughly threefold overestimation of bacterial diversity resulting from cloning and sequencing of 16S rRNA genes from the environment; however, the inclusion of genomes with a single rrn operon may lower this correction factor to ∼2.5. Divergence among operons appears to be small overall for both Bacteria and Archaea, with the vast majority of 16S rRNA sequences showing <1% nucleotide differences. Only five genomes with operons with a higher level of nucleotide divergence were detected, and Thermoanaerobacter tengcongensis exhibited the highest level of divergence (11.6%) noted to date. Overall, four of the five extreme cases of operon differences occurred among thermophilic bacteria, suggesting a much higher incidence of HGT in these bacteria than in other groups.

scholarly journals Occurrence of diazotrophic bacteria in Araucaria angustifolia

2007 ◽  
Vol 64 (3) ◽  
pp. 303-304 ◽  
Author(s):  
Rafaela de Fátima Neroni ◽  
Elke Jurandy Bran Nogueira Cardoso
Keyword(s):  
16S Rrna ◽  
Acetylene Reduction ◽  
Araucaria Angustifolia ◽  
Diazotrophic Bacteria ◽  
Araucaria Forest ◽  
Solid Media ◽  
Reduction Assay ◽  
Semi Solid ◽  
Rrna Sequences ◽  
16S Rrna Sequences

Araucaria angustifolia is an environmentally threatened tree and the whole biota of the Araucaria Forest should be investigated with the aim of its preservation. Diazotrophic bacteria are extremely important for the maintenance of ecosystems, but they have never been studied in Araucaria Forests. In this study, diazotrophic bacteria were isolated from Araucaria roots and soil, when grown in semi-specific, semi-solid media. The diazotrophic character of some recovered isolates could be confirmed using the acetylene reduction assay. According to their 16S rRNA sequences, most of these isolates belong to the genus Burkholderia.

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