scholarly journals Phylogenetic Relationship Between the Endosymbiont “candidatus Riesia Pediculicola” and Its Human Lice Host

2021 ◽  
Author(s):  
alissa hammoud ◽  
Meriem Louni ◽  
Dorothée Missé ◽  
Florence Fenollar ◽  
Oleg Mediannikov
Keyword(s):  
Evolutionary History ◽  
Housekeeping Genes ◽  
Mitochondrial Genes ◽  
Bacterial Symbionts ◽  
Pediculus Humanus ◽  
Molecular Approaches ◽  
Endosymbiotic Bacteria ◽  
Insect Phylogeny ◽  
The World ◽  
Unbalanced Diet

Abstract Background: The human louse is one of the most ancient haematophagous ectoparasites that is related intimately to its host and has been of great concern to public health throughout human history. Previously, Pediculus humanus was classified within six divergent mitochondrial clades (A, D, B, F, C and E). Like all haematophagous lice, P. humanus directly depends on the presence of bacterial symbionts, known as “Candidatus Riesia pediculicola”, to complement their unbalanced diet. In this study, we evaluated the coevolution of human lice around the world and their endosymbiotic bacteria. Using molecular approaches, we targeted lice mitochondrial genes from the six diverged clades and Candidatus R. pediculicola housekeeping genes. Methods: A total of 126 lice were selected for molecular analysis of the cytb gene for lice clade determination. In parallel, four PCR primer pairs were developed targeting three housekeeping genes of Candidatus R. pediculicola: ftsZ, groEL and two regions of the rpoB gene (rpoB-1 and rpoB-2).Results: The endosymbiont phylogeny perfectly mirrored the host insect phylogeny, using the ftsZ and rpoB-2 genes, suggesting a strict vertical transmission and a host-symbiont co-speciation following the evolutionary course of the human louse. Conclusion: Our results unequivocally indicate that lice endosymbiont have experienced a similar co-evolutionary history, and that the human louse clade can be determined by their endosymbiotic bacteria.

scholarly journals Paramecium Diversity and a New Member of the Paramecium aurelia Species Complex Described from Mexico

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 197 ◽  
Author(s):  
Alexey Potekhin ◽  
Rosaura Mayén-Estrada
Keyword(s):  
Central America ◽  
Sibling Species ◽  
Species Complex ◽  
Model Organism ◽  
Bacterial Symbionts ◽  
Ideal Model ◽  
Tropical Regions ◽  
Molecular Approaches ◽  
The World ◽  
Paramecium Jenningsi

Paramecium (Ciliophora) is an ideal model organism to study the biogeography of protists. However, many regions of the world, such as Central America, are still neglected in understanding Paramecium diversity. We combined morphological and molecular approaches to identify paramecia isolated from more than 130 samples collected from different waterbodies in several states of Mexico. We found representatives of six Paramecium morphospecies, including the rare species Paramecium jenningsi, and Paramecium putrinum, which is the first report of this species in tropical regions. We also retrieved five species of the Paramecium aurelia complex, and describe one new member of the complex, Paramecium quindecaurelia n. sp., which appears to be a sister species of Paramecium biaurelia. We discuss criteria currently applied for differentiating between sibling species in Paramecium. Additionally, we detected diverse bacterial symbionts in some of the collected ciliates.

scholarly journals A new species of Ampulicomorpha Ashmead from Eocene French amber, with a list of fossil and extant Embolemidae (Insecta: Hymenoptera) of the world

2020 ◽  
Vol 191 ◽  
pp. 20
Author(s):  
Cédric Chény ◽  
Elvis Guillam ◽  
André Nel ◽  
Vincent Perrichot
Keyword(s):  
New Species ◽  
Evolutionary History ◽  
Western Europe ◽  
Distribution Map ◽  
Single Female ◽  
Fossil Species ◽  
The World ◽  
Poor Group ◽  
A New Species ◽  
Eocene Amber

Embolemidae is a cosmopolitan but species-poor group of chrysidoid wasps with a scarce fossil record, despite a long evolutionary history since at least the Early Cretaceous. Here, the new species, Ampulicomorpha quesnoyensis sp. nov., is illustrated and described based on a single female found in Early Eocene amber of Oise (France). The new species is compared with the three other known fossil species of the genus, and a key to all fossil species of Ampulicomorpha is provided. This is the third European fossil species of Ampulicomorpha, which suggests that the genus was once well established in Western Europe while it is more widely distributed in the Eastern Palaearctic region today. A list of all fossil and extant Embolemidae of the world, as well as a map of their geographical distribution map, are provided.

scholarly journals Macrosynteny analysis between Lentinula edodes and Lentinula novae-zelandiae reveals signals of domestication in Lentinula edodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher Alan Smith
Keyword(s):  
Evolutionary History ◽  
Lentinula Edodes ◽  
Reference Genome ◽  
Genomic Change ◽  
Diverse Species ◽  
The World ◽  
Cultivated Mushroom ◽  
Genome Assemblies ◽  
High Degree ◽  
Chromosome Level

AbstractThe basidiomycete fungus Lentinula novae-zelandiae is endemic to New Zealand and is a sister taxon to Lentinula edodes, the second most cultivated mushroom in the world. To explore the biology of this organism, a high-quality chromosome level reference genome of L. novae-zelandiae was produced. Macrosyntenic comparisons between the genome assembly of L. novae-zelandiae, L. edodes and a set of three genome assemblies of diverse species from the Agaricomycota reveal a high degree of macrosyntenic restructuring within L. edodes consistent with signal of domestication. These results show L. edodes has undergone significant genomic change during the course of its evolutionary history, likely a result of its cultivation and domestication over the last 1000 years.

scholarly journals Significance of the Diversification of Wheat Species for the Assembly and Functioning of the Root-Associated Microbiome

2022 ◽  
Vol 12 ◽  
Author(s):  
Cécile Gruet ◽  
Daniel Muller ◽  
Yvan Moënne-Loccoz
Keyword(s):  
Mycorrhizal Fungi ◽  
Evolutionary History ◽  
Large Body ◽  
Taxonomic Diversity ◽  
Wheat Root ◽  
Wheat Species ◽  
Sequencing Technologies ◽  
The World ◽  
Baseline Information ◽  
Microbe Interactions

Wheat, one of the major crops in the world, has had a complex history that includes genomic hybridizations between Triticum and Aegilops species and several domestication events, which resulted in various wild and domesticated species (especially Triticum aestivum and Triticum durum), many of them still existing today. The large body of information available on wheat-microbe interactions, however, was mostly obtained without considering the importance of wheat evolutionary history and its consequences for wheat microbial ecology. This review addresses our current understanding of the microbiome of wheat root and rhizosphere in light of the information available on pre- and post-domestication wheat history, including differences between wild and domesticated wheats, ancient and modern types of cultivars as well as individual cultivars within a given wheat species. This analysis highlighted two major trends. First, most data deal with the taxonomic diversity rather than the microbial functioning of root-associated wheat microbiota, with so far a bias toward bacteria and mycorrhizal fungi that will progressively attenuate thanks to the inclusion of markers encompassing other micro-eukaryotes and archaea. Second, the comparison of wheat genotypes has mostly focused on the comparison of T. aestivum cultivars, sometimes with little consideration for their particular genetic and physiological traits. It is expected that the development of current sequencing technologies will enable to revisit the diversity of the wheat microbiome. This will provide a renewed opportunity to better understand the significance of wheat evolutionary history, and also to obtain the baseline information needed to develop microbiome-based breeding strategies for sustainable wheat farming.

Alcohol and Humans

2019 ◽  
pp. 196-206
Author(s):  
Kimberley J. Hockings ◽  
Robin I.M. Dunbar
Keyword(s):  
Alcohol Consumption ◽  
Evolutionary History ◽  
Social Role ◽  
Medical Profession ◽  
Future Research ◽  
The Social ◽  
The World ◽  
History Of

Humans and alcohol have shared a very long history. In this final chapter, we highlight some of the key findings that emerge from the chapters in this book, in particular the evolutionary history of our adaptation to alcohol consumption and the social role that alcohol consumption plays, and has played, in human societies across the world. This raises a major contradiction in the literature, namely the fact that, despite this long history, the medical profession typically views alcohol as destructive. We draw attention to several avenues that would repay future research and how humans’ relationship with alcohol stands to change and evolve.

Trematodes and snails: an intimate association

2004 ◽  
Vol 82 (2) ◽  
pp. 251-269 ◽  
Author(s):  
Anne E Lockyer ◽  
Catherine S Jones ◽  
Leslie R Noble ◽  
David Rollinson
Keyword(s):  
Evolutionary History ◽  
Intermediate Hosts ◽  
Molecular Approaches ◽  
Complex Interactions ◽  
Intimate Association ◽  
In Vitro Cell Cultures ◽  
Medical Burden ◽  
Insight Into ◽  
Trematode Parasites

Trematode parasites share an intimate relationship with their gastropod intermediate hosts, which act as the vehicle for their development and transmission. They represent an enormous economic and medical burden in developing countries, stimulating much study of snail–trematode interactions. Laboratory-maintained snail–trematode systems and in vitro cell cultures are being used to investigate the molecular dialogue between host and parasite. These dynamic and finely balanced antagonistic relationships, in which parasites strongly influence the physiology of the host, are highly specific and may occasionally demonstrate co-speciation. We consider the mechanisms and responses deployed by trematodes and snails that result in compatibility or rejection of the parasite, and the macroevolutionary implications that they may effect. Although for gastropods the fossil record gives some insight into evolutionary history, elucidation of trematode evolution must rely largely upon molecular approaches, and for both, such techniques have provided fresh and often surprising evidence of their origins and dispersal over time. Co-evolution of snails and trematodes is becoming increasingly apparent at both cellular and population levels; the implications of which are only beginning to be understood for disease control. Untangling the complex interactions of trematodes and snails promise fresh opportunities for intervention to relieve the burden of parasitic disease.

scholarly journals Evolution and taxonomy of nematode-associated entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus: an overview

Symbiosis ◽  
2020 ◽  
Vol 80 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Ewa Sajnaga ◽  
Waldemar Kazimierczak
Keyword(s):  
Evolutionary History ◽  
Entomopathogenic Nematode ◽  
Bacterial Species ◽  
Entomopathogenic Bacteria ◽  
Insecticidal Toxins ◽  
The Family ◽  
The World ◽  
History Of ◽  
Phylogenetic Origin ◽  
Animal Hosts

AbstractEntomopathogenic bacteria from the genera Photorhabdus and Xenorhabdus are closely related Gram-negative bacilli from the family Enterobacteriaceae (γ-Proteobacteria). They establish obligate mutualistic associations with soil nematodes from the genera Steinernema and Heterorhabditis to facilitate insect pathogenesis. The research of these two bacterial genera is focused mainly on their unique interactions with two different animal hosts, i.e. nematodes and insects. So far, studies of the mutualistic bacteria of nematodes collected from around the world have contributed to an increase in the number of the described Xenorhabdus and Photorhabdus species. Recently, the classification system of entomopatogenic nematode microsymbionts has undergone profound revision and now 26 species of the genus Xenorhabdus and 19 species of the genus Photorhabdus have been identified. Despite their similar life style and close phylogenetic origin, Photorhabdus and Xenorhabdus bacterial species differ significantly in e.g. the nematode host range, symbiotic strategies for parasite success, and arrays of released antibiotics and insecticidal toxins. As the knowledge of the diversity of entomopathogenic nematode microsymbionts helps to enable the use thereof, assessment of the phylogenetic relationships of these astounding bacterial genera is now a major challenge for researchers. The present article summarizes the main information on the taxonomy and evolutionary history of Xenorhabdus and Photorhabdus, entomopathogenic nematode symbionts.

scholarly journals TRI Genotyping and Chemotyping: A Balance of Power

Toxins ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 64 ◽  
Author(s):  
Ria T. Villafana ◽  
Amanda C. Ramdass ◽  
Sephra N. Rampersad
Keyword(s):  
Chronic Toxicity ◽  
Plant Pathogens ◽  
Genomic Data ◽  
Balance Of Power ◽  
Data Validation ◽  
Molecular Approaches ◽  
Wide Range ◽  
The World ◽  
Food And Feed ◽  
Regulatory Decisions

Fusarium is among the top 10 most economically important plant pathogens in the world. Trichothecenes are the principal mycotoxins produced as secondary metabolites by select species of Fusarium and cause acute and chronic toxicity in animals and humans upon exposure either through consumption and/or contact. There are over 100 trichothecene metabolites and they can occur in a wide range of commodities that form food and feed products. This review discusses strategies to mitigate the risk of mycotoxin production and exposure by examining the Fusarium-trichothecene model. Fundamental to mitigation of risk is knowing the identity of the pathogen. As such, a comparison of current, recommended molecular approaches for sequence-based identification of Fusaria is presented, followed by an analysis of the rationale and methods of trichothecene (TRI) genotyping and chemotyping. This type of information confirms the source and nature of risk. While both are powerful tools for informing regulatory decisions, an assessment of the causes of incongruence between TRI genotyping and chemotyping data must be made. Reconciliation of this discordance will map the way forward in terms of optimization of molecular approaches, which includes data validation and sharing in the form of accessible repositories of genomic data and browsers for querying such data.

scholarly journals Internalization: A metaphor we can live without

2001 ◽  
Vol 24 (4) ◽  
pp. 618-625 ◽  
Author(s):  
Michael Kubovy ◽  
William Epstein
Keyword(s):  
Natural Selection ◽  
Apparent Motion ◽  
Evolutionary History ◽  
Motion Path ◽  
The World ◽  
Kinematic Geometry ◽  
Innate Knowledge ◽  
History Of ◽  
The Mind ◽  
Internal Knowledge

Shepard has supposed that the mind is stocked with innate knowledge of the world and that this knowledge figures prominently in the way we see the world. According to him, this internal knowledge is the legacy of a process of internalization; a process of natural selection over the evolutionary history of the species. Shepard has developed his proposal most fully in his analysis of the relation between kinematic geometry and the shape of the motion path in apparent motion displays. We argue that Shepard has made a case for applying the principles of kinematic geometry to the perception of motion, but that he has not made the case for injecting these principles into the mind of the percipient. We offer a more modest interpretation of his important findings: that kinematic geometry may be a model of apparent motion. Inasmuch as our recommended interpretation does not lodge geometry in the mind of the percipient, the motivation of positing internalization, a process that moves kinematic geometry into the mind, is obviated. In our conclusion, we suggest that cognitive psychologists, in their embrace of internal mental universals and internalization may have been seduced by the siren call of metaphor.

Sign in / Sign up

Export Citation Format

Share Document