scholarly journals Does size really matter?

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
David G Heckel
Keyword(s):  
Genome Reduction ◽  
Ecological Interaction

Analysis of the smallest known arthropod genome reveals a mechanism for genome reduction that appears to be driven by a specialized ecological interaction with plants.

scholarly journals Sequence of a Coxiella endosymbiont of the tick Amblyomma nuttalli suggests a pattern of convergent genome reduction in the Coxiella genus

2020 ◽  
Author(s):  
Tiago Nardi ◽  
Emanuela Olivieri ◽  
Edward Kariuki ◽  
Davide Sassera ◽  
Michele Castelli
Keyword(s):  
Coxiella Burnetii ◽  
Phylogenetic Analyses ◽  
Genome Reduction ◽  
Metabolic Profiles ◽  
The Novel ◽  
Bacterial Symbionts ◽  
Human Pathogen ◽  
Host Genus ◽  
Supportive Role ◽  
Genus One

Abstract Ticks require bacterial symbionts for the provision of necessary compounds that are absent in their hematophagous diet. Such symbionts are frequently vertically transmitted and, most commonly, belong to the Coxiella genus, which also includes the human pathogen Coxiella burnetii. This genus can be divided in four main clades, presenting partial but incomplete co-cladogenesis with the tick hosts. Here we report the genome sequence of a novel Coxiella, endosymbiont of the African tick Amblyomma nuttalli, and the ensuing comparative analyses. Its size (~1 Mb) is intermediate between symbionts of Rhipicephalus species and other Amblyomma species. Phylogenetic analyses show that the novel sequence is the first genome of the B clade, the only one for which no genomes were previously available. Accordingly, it allows to draw an enhanced scenario of the evolution of the genus, one of parallel genome reduction of different endosymbiont lineages, which are now at different stages of reduction from a more versatile ancestor. Gene content comparison allows to infer that the ancestor could be reminiscent of Coxiella burnetii. Interestingly, the convergent loss of mismatch repair could have been a major driver of such reductive evolution. Predicted metabolic profiles are rather homogenous among Coxiella endosymbionts, in particular vitamin biosynthesis, consistently with a host-supportive role. Concurrently, similarities among Coxiella endosymbionts according to host genus and despite phylogenetic unrelatedness hint at possible host-dependent effects.

Mechanisms driving genome reduction of a novel Roseobacter lineage

2021 ◽  
Author(s):  
Xiaoyuan Feng ◽  
Xiao Chu ◽  
Yang Qian ◽  
Michael W. Henson ◽  
V. Celeste Lanclos ◽  
...  
Keyword(s):  
Genome Reduction

scholarly journals Genome Reduction and Secondary Metabolism of the Marine Sponge-Associated Cyanobacterium Leptothoe

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 298
Author(s):  
Despoina Konstantinou ◽  
Rafael V. Popin ◽  
David P. Fewer ◽  
Kaarina Sivonen ◽  
Spyros Gkelis
Keyword(s):  
Natural Products ◽  
Microbial Communities ◽  
Genomic Analysis ◽  
Gene Clusters ◽  
Marine Sponges ◽  
Genome Reduction ◽  
Extracellular Polysaccharides ◽  
Comparative Genomic ◽  
Symbiotic Relationships ◽  
Genes Encoding

Sponges form symbiotic relationships with diverse and abundant microbial communities. Cyanobacteria are among the most important members of the microbial communities that are associated with sponges. Here, we performed a genus-wide comparative genomic analysis of the newly described marine benthic cyanobacterial genus Leptothoe (Synechococcales). We obtained draft genomes from Le. kymatousa TAU-MAC 1615 and Le. spongobia TAU-MAC 1115, isolated from marine sponges. We identified five additional Leptothoe genomes, host-associated or free-living, using a phylogenomic approach, and the comparison of all genomes showed that the sponge-associated strains display features of a symbiotic lifestyle. Le. kymatousa and Le. spongobia have undergone genome reduction; they harbored considerably fewer genes encoding for (i) cofactors, vitamins, prosthetic groups, pigments, proteins, and amino acid biosynthesis; (ii) DNA repair; (iii) antioxidant enzymes; and (iv) biosynthesis of capsular and extracellular polysaccharides. They have also lost several genes related to chemotaxis and motility. Eukaryotic-like proteins, such as ankyrin repeats, playing important roles in sponge-symbiont interactions, were identified in sponge-associated Leptothoe genomes. The sponge-associated Leptothoe stains harbored biosynthetic gene clusters encoding novel natural products despite genome reduction. Comparisons of the biosynthetic capacities of Leptothoe with chemically rich cyanobacteria revealed that Leptothoe is another promising marine cyanobacterium for the biosynthesis of novel natural products.

scholarly journals Letting go: bacterial genome reduction solves the dilemma of adapting to predation mortality in a substrate-restricted environment

2017 ◽  
Vol 11 (10) ◽  
pp. 2258-2266 ◽  
Author(s):  
Michael Baumgartner ◽  
Stefan Roffler ◽  
Thomas Wicker ◽  
Jakob Pernthaler
Keyword(s):  
Bacterial Genome ◽  
Genome Reduction ◽  
Predation Mortality ◽  
Letting Go ◽  
Restricted Environment

scholarly journals Genome reduction in Leptospira borgpetersenii reflects limited transmission potential

2006 ◽  
Vol 103 (39) ◽  
pp. 14560-14565 ◽  
Author(s):  
D. M. Bulach ◽  
R. L. Zuerner ◽  
P. Wilson ◽  
T. Seemann ◽  
A. McGrath ◽  
...  
Keyword(s):  
Genome Reduction ◽  
Transmission Potential ◽  
Leptospira Borgpetersenii

scholarly journals Microsporidian Introns Retained against a Background of Genome Reduction: Characterization of an Unusual Set of Introns

2018 ◽  
Vol 11 (1) ◽  
pp. 263-269 ◽  
Author(s):  
Thomas A Whelan ◽  
Nicole T Lee ◽  
Renny C H Lee ◽  
Naomi M Fast
Keyword(s):  
Genome Reduction

Causes and effects of nuclear genome reduction

2005 ◽  
Vol 15 (6) ◽  
pp. 601-608 ◽  
Author(s):  
Patrick J Keeling ◽  
Claudio H Slamovits
Keyword(s):  
Nuclear Genome ◽  
Genome Reduction

scholarly journals Beyond species: why ecological interaction networks vary through space and time

Oikos ◽  
2014 ◽  
Vol 124 (3) ◽  
pp. 243-251 ◽  
Author(s):  
Timothée Poisot ◽  
Daniel B. Stouffer ◽  
Dominique Gravel
Keyword(s):  
Interaction Networks ◽  
Ecological Interaction ◽  
Space And Time
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