scholarly journals Revisiting the evolution and taxonomy of Clostridia, a phylogenomic update

2019 ◽  
Author(s):  
Pablo Cruz-Morales ◽  
Camila A. Orellana ◽  
George Moutafis ◽  
Glenn Moonen ◽  
Gonzalo Rincon ◽  
...  
Keyword(s):  
Single Species ◽  
Sensu Stricto ◽  
Wall Structure ◽  
Central Metabolism ◽  
New Classification ◽  
Animal Pathogens ◽  
Large Genus ◽  
Taxonomic Studies ◽  
Toxin Evolution

AbstractClostridium is a large genus of obligate anaerobes belonging to the Firmicutes phylum of bacteria, most of which have a Gram-positive cell wall structure. The genus includes significant human and animal pathogens, causative of potentially deadly diseases such as tetanus and botulism. Despite their relevance and many studies suggesting that they are not a monophyletic group, the taxonomy of the group has largely been neglected. Currently, species belonging to the genus are placed in the unnatural order defined as Clostridiales, which includes the class Clostridia. Here we used genomic data from 779 strains to study the taxonomy and evolution of the group. This analysis allowed us to; (i) confirm that the group is composed of more than one genus (ii), detect major differences between pathogens classified as a single species within the group of authentic Clostridium spp. (sensu stricto), identify inconsistencies between taxonomy and toxin evolution that reflect on the pervasive misclassification of strains and, (iv) identify differential traits within central metabolism of members of what has been defined earlier and confirmed by us as cluster I. Our analysis shows that the current taxonomic classification of Clostridium species hinders the prediction of functions and traits, suggests a new classification for this fascinating class of bacteria and highlights the importance of phylogenomics for taxonomic studies.

scholarly journals Revisiting the Evolution and Taxonomy of Clostridia, a Phylogenomic Update

2019 ◽  
Vol 11 (7) ◽  
pp. 2035-2044 ◽  
Author(s):  
Pablo Cruz-Morales ◽  
Camila A Orellana ◽  
George Moutafis ◽  
Glenn Moonen ◽  
Gonzalo Rincon ◽  
...  
Keyword(s):  
Single Species ◽  
Sensu Stricto ◽  
Wall Structure ◽  
Clostridium Species ◽  
Animal Pathogens ◽  
Large Genus ◽  
Genus 2 ◽  
Taxonomic Studies ◽  
Toxin Evolution

Abstract Clostridium is a large genus of obligate anaerobes belonging to the Firmicutes phylum of bacteria, most of which have a Gram-positive cell wall structure. The genus includes significant human and animal pathogens, causative of potentially deadly diseases such as tetanus and botulism. Despite their relevance and many studies suggesting that they are not a monophyletic group, the taxonomy of the group has largely been neglected. Currently, species belonging to the genus are placed in the unnatural order defined as Clostridiales, which includes the class Clostridia. Here, we used genomic data from 779 strains to study the taxonomy and evolution of the group. This analysis allowed us to 1) confirm that the group is composed of more than one genus, 2) detect major differences between pathogens classified as a single species within the group of authentic Clostridium spp. (sensu stricto), 3) identify inconsistencies between taxonomy and toxin evolution that reflect on the pervasive misclassification of strains, and 4) identify differential traits within central metabolism of members of what has been defined earlier and confirmed by us as cluster I. Our analysis shows that the current taxonomic classification of Clostridium species hinders the prediction of functions and traits, suggests a new classification for this fascinating class of bacteria, and highlights the importance of phylogenomics for taxonomic studies.

scholarly journals A KARYOSYSTEMATIC INVESTIGATION IN THE GRAMINEAE

1934 ◽  
Vol 11 (2) ◽  
pp. 213-241 ◽  
Author(s):  
A. W. S. Hunter
Keyword(s):  
Chromosome Number ◽  
Basic Number ◽  
Chromosome Morphology ◽  
The Other ◽  
Anthoxanthum Odoratum ◽  
Large Genus ◽  
Taxonomic Studies ◽  
Different Characteristics ◽  
First Time

The history and the present state of the classification of the Gramineae are briefly reviewed and a number of the different characteristics on which phylogenetic systems have been based are considered. The subjects of chromosome morphology and the application of idiograms and karyotypes to taxonomic studies are discussed. Avdulov's recently reported findings on the phylogeny of the grasses are summarized and compared with the results of other workers and those obtained in the present investigation. Three species of bamboos were studied for the first time and evidence secured to indicate that the basic number of the tribe is probably not 12 as has been elsewhere reported. In the Festuceae the chromosome number of Phragmites communis Trin. was definitely ascertained, confirming Avdulov's supposition that the basic number for the genus is 12. The other three species investigated agreed with the arrangement as proposed by Avdulov. The tribe Chlorideae, with the exception of the genus Beckmannia, has been reported to be almost entirely Panicoid with respect to chromosome morphology. This was confirmed in the four species examined. Avdulov's rearrangement of the tribe Hordeae was somewhat altered and a confusion m the nomenclature of the genus Lepturus was corrected. An anomalous situation was cleared up in the tribe Agrostideae by the establishment of the chromosome number of Sporobolus tennuissinus Kuntz as 40. The specimen of Anthoxanthum odoratum L. (tribe Phalarideae) examined provided a very interesting example of secondary splitting in somatic chromosomes. One species was examined in the tribe Melinideae and six in the tribe Paniceae. In the latter tribe no difference could be detected between the several subdivisions of the genus Panicum. The same condition held for the large genus Andropogon in the tribe Andropogoneae. In the tribe Maydeae the chromosome number of Tripsacum dactyloides L. was found to be 9, and the suggestion was made that it may be a link, along with the genus Coix, between the Andropogoneae and the Maydeae. The other four species examined all had a basic number of 10.

A new classification of rosette-forming Brachyglottis (Asteraceae: Senecioneae) recognising a single species: Brachyglottis lagopus

2018 ◽  
Vol 56 (3) ◽  
pp. 237-263 ◽  
Author(s):  
Timothy R. Millar ◽  
Ilse Breitwieser ◽  
Pieter B. Pelser ◽  
Rob D. Smissen
Keyword(s):  
Single Species ◽  
New Classification

Replacement name for Cleta Mulsant, 1850 (Coleoptera: Coccinellidae: Epilachnini)

Zootaxa ◽  
2020 ◽  
Vol 4869 (1) ◽  
pp. 149-150
Author(s):  
KAROL SZAWARYN ◽  
WIOLETTA TOMASZEWSKA
Keyword(s):  
Type Species ◽  
New World ◽  
Molecular Data ◽  
Sensu Stricto ◽  
New Classification ◽  
Ladybird Beetles ◽  
The Family ◽  
Morphological And Molecular Data ◽  
World Fauna

Recently the classification of the ladybird beetles’ tribe Epilachnini was revised based on morphological and molecular data (Szawaryn et al. 2015, Tomaszewska & Szawaryn 2016). Based on these findings a new classification of the tribe was proposed. The genus Epilachna Chevrolat in Dejean, 1837 sensu lato was split into several clades, with Epilachna sensu stricto limited to New World fauna, and one of the Afrotropical clades, formerly defined as Epilachna sahlbergi-group (Fürsch 1963), has been named Chazeauiana Tomaszewska & Szawaryn, 2015 (Szawaryn et al. 2015), with Epilachna sahlbergi Mulsant, 1850 as the type species. However, that taxon received an unnecessary replacement name, as Mulsant (1850) already described a subgenus of Epilachna named Cleta distributed in Afrotropics, with Epilachna eckloni Mulsant, 1850 as the type species, which also belongs to the E. sahlbergi-group. Consequently Cleta has been elevated to the genus level (Tomaszewska & Szawaryn 2016) and Chazeuiana was synonymized with Cleta as a junior synonym. Nonetheless, authors (Tomaszewska & Szawaryn 2016) were not aware that the name Cleta is preoccupied. It appeared that Duponchel (1845) established the genus Cleta in the family Geometridae (Lepidoptera) that makes Cleta Mulsant (1850) a junior homonym. Therefore, we propose here Afrocleta nom. nov. as a replacement name for Cleta Mulsant, 1850. 

Lactistes obesipes Signoret, 1879 (Hemiptera: Cydnidae)—the burrower bug enigma: redescription, synonymy, and remarks on its distribution and taxonomic status

Zootaxa ◽  
2008 ◽  
Vol 1933 (1) ◽  
pp. 66-68
Author(s):  
JERZY A. LIS ◽  
BARBARA LIS
Keyword(s):  
Taxonomic Status ◽  
Single Species ◽  
Female Specimen ◽  
Single Female ◽  
New Classification ◽  
Australian Region

The genus Lactistes Schiødte, 1847 (Cydnidae: Cydninae: Geotomini sensu lato – for a new classification of the Cydnidae, see Pluot-Sigwalt & J.A. Lis, 2008) comprises 15 species distributed in the Palaearctic, Afrotropical, and Oriental Regions, and only a single species reported from the Australian Region (J.A. Lis 1996, 1999; Cassis & Gross 2002). This species, named Lactistes obesipes, was described three times by Signoret in three different papers (1879, 1880, 1881) from an unknown locality in Australia (firstly as “Nouvelle-Hollande”, then as “Australie”) on the basis of the same single female specimen.

New Classification of Gemstone Colours

1971 ◽  
Vol 12 (7) ◽  
pp. 262-266
Author(s):  
K. F. Chudoba
Keyword(s):  
New Classification

Reductionism and holism in the philosophy of medicine

2020 ◽  
pp. 66-74
Author(s):  
E. Zakablukovskiy
Keyword(s):  
Philosophy Of Medicine ◽  
Point Of View ◽  
Social Model ◽  
Macro Level ◽  
New Classification

The article highlights certain aspects of the discussion on the topic of reductionism vs. holism in the philosophy of medicine. Classic radical reductionism is defeated by the concept of emergence. The s.c. bio-medical point of view on a malady, despite its relevance and clear benefit, is not recognized as universal as its adherents may claim, and it yields to an integral psycho-bio-social model. The author introduces a new classification of holism (vitalistic, social and individualistic) and makes appropriate recommendations to clinicians. It is social holism at the macro level that has proven effective in combating the spread of COVID-19.

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