Weights of Weierstrass points in double coverings of curves of genus one or two

1986 ◽  
Vol 55 (3-4) ◽  
pp. 419-432 ◽  
Author(s):  
Arnaldo Garcia
Keyword(s):  
Weierstrass Points ◽  
Genus One ◽  
Double Coverings ◽  
Double Coverings Of Curves

Weierstrass points and double coverings of curves

1994 ◽  
Vol 83 (1) ◽  
pp. 39-58 ◽  
Author(s):  
Fernando Torres
Keyword(s):  
Weierstrass Points ◽  
Double Coverings ◽  
Double Coverings Of Curves

A characterization of double coverings of curves

2015 ◽  
Vol 150 (3-4) ◽  
pp. 465-474
Author(s):  
Takao Kato ◽  
Gerriet Martens
Keyword(s):  
Double Coverings ◽  
Double Coverings Of Curves

Pencils on double coverings of curves

2008 ◽  
Vol 92 (1) ◽  
pp. 35-43
Author(s):  
Luis Fuentes García
Keyword(s):  
Double Coverings ◽  
Double Coverings Of Curves

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.

Sign in / Sign up

Export Citation Format

Share Document