This work reports the results of analyses of three complete mycoplasma genomes, a pathogenic (7448) and a nonpathogenic (J) strain of the swine pathogenMycoplasma hyopneumoniaeand a strain of the avian pathogenMycoplasma synoviae; the genome sizes of the three strains were 920,079 bp, 897,405 bp, and 799,476 bp, respectively. These genomes were compared with other sequenced mycoplasma genomes reported in the literature to examine several aspects of mycoplasma evolution. Strain-specific regions, including integrative and conjugal elements, and genome rearrangements and alterations in adhesin sequences were observed in theM. hyopneumoniaestrains, and all of these were potentially related to pathogenicity. Genomic comparisons revealed that reduction in genome size implied loss of redundant metabolic pathways, with maintenance of alternative routes in different species. Horizontal gene transfer was consistently observed betweenM. synoviaeandMycoplasma gallisepticum. Our analyses indicated a likely transfer event of hemagglutinin-coding DNA sequences fromM. gallisepticumtoM. synoviae.

Aims: Cyanobacteria‐deprived lichens of the species Canoparmelia caroliniana, Canoparmelia crozalsiana, Canoparmelia texana, Parmotrema sancti‐angeli and Parmotrema tinctorum were screened for the presence of chemo‐organotrophic nitrogen‐fixing bacteria. Methods and Results: Fifty‐three lichen samples subjected to enrichment selection using a nitrogen‐free minimal medium were positive for acetylene reduction. Seventeen isolates, able to fix nitrogen, belonged to Gamma‐proteobacteria group and were identified as: Acinetobacter sp., Pantoea sp., Pseudomonas sp., Pseudomonas stutzeri, Serratia marcescens and Stenotrophomonas maltophilia, according to 16S rRNA gene sequences and biochemical tests. The excretion of amino acid and phytohormone and the ability of mineral phosphate solubilization were determined in 14 isolates. All isolates were able to release amino acids and 3‐indoleacetic acid. About 64% of the isolates solubilized phosphates and 30% released ethylene. Conclusions: These data confirm sparse evidence from the literature on the occurrence of chemo‐organotrophic nitrogen‐fixing bacteria in cyanobacteria‐deprived lichens; the isolates presented physiologic features which might benefit the host if they are expressed when the bacteria are harboured by lichens. Significance and Impact of the Study: Chemo‐organotrophic nitrogen‐fixing bacteria were isolated from a high percentage (72·6%) of cyanobacteria‐deprived lichens. All isolates presented important physiological characteristics, some of which are being described here for the first time.

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae . More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vector–human and vector–parasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles-darlingi .

Endosymbiont-bearing trypanosomatids have been considered excellent models for the study of cell evolution because the host protozoan co-evolves with an intracellular bacterium in a mutualistic relationship. Such protozoa inhabit a single invertebrate host during their entire life cycle and exhibit special characteristics that group them in a particular phylogenetic cluster of the Trypanosomatidae family, thus classified as monoxenics. In an effort to better understand such symbiotic association, we used DNA pyrosequencing and a reference-guided assembly to generate reads that predicted 16,960 and 12,162 open reading frames (ORFs) in two symbiont-bearing trypanosomatids, Angomonas deanei (previously named as Crithidia deanei ) and Strigomonas culicis (first known as Blastocrithidia culicis ), respectively. Identification of each ORF was based primarily on TriTrypDB using tblastn, and each ORF was confirmed by employing getorf from EMBOSS and Newbler 2.6 when necessary. The monoxenic organisms revealed conserved housekeeping functions when compared to other trypanosomatids, especially compared with Leishmania major . However, major differences were found in ORFs corresponding to the cytoskeleton, the kinetoplast, and the paraflagellar structure. The monoxenic organisms also contain a large number of genes for cytosolic calpain-like and surface gp63 metalloproteases and a reduced number of compartmentalized cysteine proteases in comparison to other TriTryp organisms, reflecting adaptations to the presence of the symbiont. The assembled bacterial endosymbiont sequences exhibit a high A+T content with a total of 787 and 769 ORFs for the Angomonas deanei and Strigomonas culicis endosymbionts, respectively, and indicate that these organisms hold a common ancestor related to the Alcaligenaceae family. Importantly, both symbionts contain enzymes that complement essential host cell biosynthetic pathways, such as those for amino acid, lipid and purine/pyrimidine metabolism. These findings increase our understanding of the intricate symbiotic relationship between the bacterium and the trypanosomatid host and provide clues to better understand eukaryotic cell evolution.