scholarly journals Phylogenetic origin and sequence features of MreB from the wall-less swimming bacteria Spiroplasma

2020 ◽  
Author(s):  
Daichi Takahashi ◽  
Ikuko Fujiwara ◽  
Makoto Miyata
Keyword(s):  
Maximum Likelihood Method ◽  
Bone Structure ◽  
Likelihood Method ◽  
Flagellar Motility ◽  
Sequence Comparisons ◽  
Sequence Features ◽  
Protein Protein Interaction ◽  
Swimming Bacteria ◽  
Phylogenetic Origin ◽  
Unique Mechanism

ABSTRACTSpiroplasma are wall-less bacteria which belong to the phylum Tenericutes that evolved from Firmicutes including Bacillus subtilis. Spiroplasma swim by a mechanism unrelated to widespread bacterial motilities, such as flagellar motility, and caused by helicity switching with kinks traveling along the helical cell body. The swimming force is likely generated by five classes of bacterial actin homolog MreBs (SMreBs 1-5) involved in the helical bone structure. We analyzed sequences of SMreBs to clarify their phylogeny and sequence features. The maximum likelihood method based on around 5,000 MreB sequences showed that the phylogenetic tree was divided into several radiations. SMreBs formed a clade adjacent to the radiation of MreBH, an MreB isoform of Firmicutes. Sequence comparisons of SMreBs and Bacillus MreBs were also performed to clarify the features of SMreB. Catalytic glutamic acid and threonine were substituted to aspartic acid and lysine, respectively, in SMreB3. In SMreBs 2 and 4, amino acids involved in inter- and intra-protofilament interactions were significantly different from those in Bacillus MreBs. A membrane-binding region was not identified in most SMreBs 1 and 4 unlike many walled-bacterial MreBs. SMreB5 had a significantly longer C-terminal region than the other MreBs, which possibly forms a protein-protein interaction. These features may support the functions responsible for the unique mechanism of Spiroplasma swimming.

The co-responsibility of mass and environment in the formation of lenticular galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 173-174
Author(s):  
A. Cortesi ◽  
L. Coccato ◽  
M. L. Buzzo ◽  
K. Menéndez-Delmestre ◽  
T. Goncalves ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Maximum Likelihood Method ◽  
Spiral Galaxies ◽  
Galactic Nuclei ◽  
Rotation Velocity ◽  
Elliptical Galaxies ◽  
Likelihood Method ◽  
Data Set ◽  
Lenticular Galaxies ◽  
Galaxies Kinematics

AbstractWe present the latest data release of the Planetary Nebulae Spectrograph Survey (PNS) of ten lenticular galaxies and two spiral galaxies. With this data set we are able to recover the galaxies’ kinematics out to several effective radii. We use a maximum likelihood method to decompose the disk and spheroid kinematics and we compare it with the kinematics of spiral and elliptical galaxies. We build the Tully- Fisher (TF) relation for these galaxies and we compare with data from the literature and simulations. We find that the disks of lenticular galaxies are hotter than the disks of spiral galaxies at low redshifts, but still dominated by rotation velocity. The mechanism responsible for the formation of these lenticular galaxies is neither major mergers, nor a gentle quenching driven by stripping or Active Galactic Nuclei (AGN) feedback.

Phylogenetic Analysis of Black Peper (Piper Spp.) Population Collected in Different Locations of Vietnam Based on the ITSU1-4 Gene Region

2021 ◽  
Author(s):  
Sonexay Rasphone ◽  
Long Thanh Dang ◽  
Hoan Nguyen ◽  
Ngoc Quang Nguyen ◽  
Oanh Thi Duong ◽  
...  
Keyword(s):  
Dna Barcoding ◽  
Ribosomal Dna ◽  
Maximum Likelihood Method ◽  
Dna Barcode ◽  
Population Expansion ◽  
Nuclear Ribosomal Dna ◽  
Likelihood Method ◽  
Gene Region ◽  
Universal Primers ◽  
Intraspecific Distance

Abstract Background: The internal transcribed spacer (ITS) of nuclear ribosomal DNA is one of the most commonly used DNA markers in plant phylogenetic and DNA barcoding analyses, and it has been recommended as a core plant DNA barcode. To compare and find out the analysis genetic diversity difference some pepper individuals collected in different localities in Vietnam when using the ITS of nuclear ribosomal DNA. The ITS gene region from the nuclear genomes were tested for their suitability as DNA barcoding regions of thirty-nine pepper individuals. Universal primers were used, and sequenced products were analyzed using the Maximum Likelihood method and Tamura-Nei model in the MEGA X program.Results: We did not observe high variability in intraspecific distance within the ITSu1-4 gene region between individuals, ranged from 0.000 to 0.155 (mean = 0.033). The size of the gene region has fluctuated from 667 to 685 bp between different individuals with the percentage (G + C) contained in the ITSu1-4 gene region was ranged from 54.776% to 60.805%, mean = 60.174%. The values of Fu’s Fs, D, Fu and Li’s D* and F* were negative as well (Fs = -0.209, D = -1.824; P < 0.05, D* = -1.205; not significant, P > 0.10 and F* = -1.699; not significant, 0.10 > P > 0.05), indicating an excess of recently derived haplotypes and suggesting that either population expansion or background selection has occurred. The value Strobeck’s S the obtained between individuals in a population is high (S = 0.684). The results of evolutionary relationships of taxa obtained 3 groups with the highest value of Fst is shown in the pairs of groups II and III (Fst = 0.151), and the lowest is in groups II and I (Fst = 0.015). All of the new sequences have been deposited in GeneBank under the following accession numbers MZ636718 to MZ636756.Conclusions: This database is an important resource for researchers working on Species of pepper in Vietnam and also provides a tool to create ITSu1-4 databases for any given taxonomy.

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