Lateral gene transfer (LGT) is an important mechanism of evolution for protists adapting to oxygen-poor environments. Specifically, modifications of energy metabolism in anaerobic forms of mitochondria (e.g., hydrogenosomes) are likely to have been associated with gene transfer from prokaryotes. An interesting question is whether the products of transferred genes were directly targeted into the ancestral organelle or initially operated in the cytosol and subsequently acquired organelle-targeting sequences. Here, we identified key enzymes of hydrogenosomal metabolism in the free-living anaerobic amoebozoan Mastigamoeba balamuthi and analyzed their cellular localizations, enzymatic activities, and evolutionary histories. Additionally, we characterized 1) several canonical mitochondrial components including respiratory complex II and the glycine cleavage system, 2) enzymes associated with anaerobic energy metabolism, including an unusual D-lactate dehydrogenase and acetyl CoA synthase, and 3) a sulfate activation pathway. Intriguingly, components of anaerobic energy metabolism are present in at least two gene copies. For each component, one copy possesses an mitochondrial targeting sequence (MTS), whereas the other lacks an MTS, yielding parallel cytosolic and hydrogenosomal extended glycolysis pathways. Experimentally, we confirmed that the organelle targeting of several proteins is fully dependent on the MTS. Phylogenetic analysis of all extended glycolysis components suggested that these components were acquired by LGT. We propose that the transformation from an ancestral organelle to a hydrogenosome in the M. balamuthi lineage involved the lateral acquisition of genes encoding extended glycolysis enzymes that initially operated in the cytosol and that established a parallel hydrogenosomal pathway after gene duplication and MTS acquisition.

• MeSH
• anaerobióza genetika   MeSH
• Archamoebae enzymologie   genetika   metabolismus   MeSH
• duplikace genu * MeSH
• energetický metabolismus genetika   MeSH
• enzymy genetika   izolace a purifikace   MeSH
• molekulární evoluce * MeSH
• organely enzymologie   genetika   metabolismus   MeSH
• přenos genů horizontální * MeSH
• struktury buněčné membrány genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

p-Cresol and indole are volatile biologically active products of the bacterial degradation of tyrosine and tryptophan respectively. They are typically produced by bacteria in animal intestines, soil and various sediments. Here, we demonstrate that the free-living eukaryote Mastigamoeba balamuthi and its pathogenic relative Entamoeba histolytica produce significant amounts of indole via tryptophanase activity. Unexpectedly, M. balamuthi also produces p-cresol in concentrations that are bacteriostatic to non-p-cresol-producing bacteria. The ability of M. balamuthi to produce p-cresol, which has not previously been observed in any eukaryotic microbe, was gained due to the lateral acquisition of a bacterial gene for 4-hydroxyphenylacetate decarboxylase (HPAD). In bacteria, the genes for HPAD and the S-adenosylmethionine-dependent activating enzyme (AE) are present in a common operon. In M. balamuthi, HPAD displays a unique fusion with the AE that suggests the operon-mediated transfer of genes from a bacterial donor. We also clarified that the tyrosine-to-4-hydroxyphenylacetate conversion proceeds via the Ehrlich pathway. The acquisition of the bacterial HPAD gene may provide M. balamuthi a competitive advantage over other microflora in its native habitat.

• MeSH
• Archamoebae genetika   MeSH
• Bacteria genetika   MeSH
• bakteriální geny * MeSH
• indoly metabolismus   MeSH
• karboxylyasy MeSH
• kresoly metabolismus   MeSH
• operon MeSH
• přenos genů horizontální * MeSH
• S-adenosylmethionin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Bacteria influence eukaryotic biology as parasitic, commensal or beneficial symbionts. Aside from these organismal interactions, bacteria have also been important sources of new genetic sequences through horizontal gene transfer (HGT) for eukaryotes. In this Review, we focus on gene transfers from bacteria to eukaryotes, discuss how horizontally transferred genes become functional and explore what functions are endowed upon a broad diversity of eukaryotes by genes derived from bacteria. We classify HGT events into two broad types: those that maintain pre-existing functions and those that provide the recipient with new functionality, including altered host nutrition, protection and adaptation to extreme environments.

• MeSH
• Bacteria genetika   MeSH
• biologická evoluce MeSH
• Eukaryota genetika   MeSH
• fyziologická adaptace genetika   MeSH
• přenos genů horizontální fyziologie   MeSH
• regulace genové exprese MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Alphaproteobacteria, which are the most abundant microorganisms of temperate oceans, produce phage-like particles called gene transfer agents (GTAs) that mediate lateral gene exchange. However, the mechanism by which GTAs deliver DNA into cells is unknown. Here we present the structure of the GTA of Rhodobacter capsulatus (RcGTA) and describe the conformational changes required for its DNA ejection. The structure of RcGTA resembles that of a tailed phage, but it has an oblate head shortened in the direction of the tail axis, which limits its packaging capacity to less than 4,500 base pairs of linear double-stranded DNA. The tail channel of RcGTA contains a trimer of proteins that possess features of both tape measure proteins of long-tailed phages from the family Siphoviridae and tail needle proteins of short-tailed phages from the family Podoviridae. The opening of a constriction within the RcGTA baseplate enables the ejection of DNA into bacterial periplasm.

• MeSH
• bakteriofágy genetika   fyziologie   ultrastruktura   MeSH
• DNA bakterií genetika   MeSH
• elektronová kryomikroskopie MeSH
• přenos genů horizontální MeSH
• regulace genové exprese u bakterií MeSH
• Rhodobacter capsulatus genetika   virologie   MeSH
• Siphoviridae genetika   fyziologie   ultrastruktura   MeSH
• technika přenosu genů * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Horizontal gene transfer from bacteria to eukaryotes is the subject of much debate. A recent study reveals the instrumental role that the acquisition of bacterial nucleotide transporters played in the evolution of the ubiquitous, intracellular eukaryotic parasites, the microsporidia.

• MeSH
• eukaryotické buňky MeSH
• membránové transportní proteiny * MeSH
• Microsporidia * MeSH
• paraziti * MeSH
• přenos genů horizontální MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• komentáře MeSH

Rickettsiales are obligate intracellular bacteria originally found in metazoans, but more recently recognized as widespread endosymbionts of various protists. One genus was detected also in several green algae, but reports on rickettsialean endosymbionts in other algal groups are lacking. Here we show that several distantly related eustigmatophytes (coccoid algae belonging to Ochrophyta, Stramenopiles) are infected by Candidatus Phycorickettsia gen. nov., a new member of the family Rickettsiaceae. The genome sequence of Ca. Phycorickettsia trachydisci sp. nov., an endosymbiont of Trachydiscus minutus CCALA 838, revealed genomic features (size, GC content, number of genes) typical for other Rickettsiales, but some unusual aspects of the gene content were noted. Specifically, Phycorickettsia lacks genes for several components of the respiration chain, haem biosynthesis pathway, or c-di-GMP-based signalling. On the other hand, it uniquely harbours a six-gene operon of enigmatic function that we recently reported from plastid genomes of two distantly related eustigmatophytes and from various non-rickettsialean bacteria. Strikingly, the eustigmatophyte operon is closely related to the one from Phycorickettsia, suggesting a gene transfer event between the endosymbiont and host lineages in early eustigmatophyte evolution. We hypothesize an important role of the operon in the physiology of Phycorickettsia infection and a long-term eustigmatophyte-Phycorickettsia coexistence.

• MeSH
• genomika MeSH
• Heterokontophyta mikrobiologie   MeSH
• operon MeSH
• přenos genů horizontální * MeSH
• Rickettsiaceae genetika   MeSH
• symbióza MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Previous work had shown that a sequence homologous to the gene encoding class II hydrophobin cerato-ulmin from the fungus Ophiostoma novo-ulmi, the causal agent of Dutch Elm Disease (DED), was present in a strain of the unrelated species Geosmithia species 5 (Ascomycota: Hypocreales) isolated from Ulmus minor affected by DED. As both fungi occupy the same habitat, even if different ecological niches, the occurrence of horizontal gene transfer was proposed. In the present work we have analysed for the presence of the cerato-ulmin gene 70 Geosmithia strains representing 29 species, isolated from different host plants and geographic locations. The gene was found in 52.1 % of the strains derived from elm trees, while none of those isolated from nonelms possessed it. The expression of the gene in Geosmithia was also assessed by real time PCR in different growth conditions (liquid culture, solid culture, elm sawdust, dual culture with O. novo-ulmi), and was found to be extremely low in all conditions tested. On the basis of these results we propose that the cerato-ulmin gene is not functional in Geosmithia, but can be considered instead a marker of more extensive transfers of genetic material as shown in other fungi.

• MeSH
• Ascomycota genetika   izolace a purifikace   MeSH
• fungální proteiny genetika   MeSH
• geny hub MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• molekulární sekvence - údaje MeSH
• mykotoxiny genetika   MeSH
• nemoci rostlin mikrobiologie   MeSH
• přenos genů horizontální * MeSH
• sekvenční analýza DNA MeSH
• stanovení celkové genové exprese MeSH
• Ulmus mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Horizontal gene transfer (HGT) is a key driver in the evolution of bacterial genomes. The acquisition of genes mediated by HGT may enable bacteria to adapt to ever-changing environmental conditions. Long-term application of antibiotics in intensive agriculture is associated with the dissemination of antibiotic resistance genes among bacteria with the consequences causing public health concern. Commensal farm-animal-associated gut microbiota are considered the reservoir of the resistance genes. Therefore, in this study, we identified known and not-yet characterized mobilized genes originating from chicken and porcine fecal samples using our innovative pipeline followed by network analysis to provide appropriate visualization to support proper interpretation.

• MeSH
• antibakteriální látky MeSH
• Bacteria genetika   MeSH
• bakteriální geny MeSH
• genom bakteriální MeSH
• mikrobiota * MeSH
• prasata MeSH
• přenos genů horizontální * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The smallest reported bacterial genome belongs to Tremblaya princeps, a symbiont of Planococcus citri mealybugs (PCIT). Tremblaya PCIT not only has a 139 kb genome, but possesses its own bacterial endosymbiont, Moranella endobia. Genome and transcriptome sequencing, including genome sequencing from a Tremblaya lineage lacking intracellular bacteria, reveals that the extreme genomic degeneracy of Tremblaya PCIT likely resulted from acquiring Moranella as an endosymbiont. In addition, at least 22 expressed horizontally transferred genes from multiple diverse bacteria to the mealybug genome likely complement missing symbiont genes. However, none of these horizontally transferred genes are from Tremblaya, showing that genome reduction in this symbiont has not been enabled by gene transfer to the host nucleus. Our results thus indicate that the functioning of this three-way symbiosis is dependent on genes from at least six lineages of organisms and reveal a path to intimate endosymbiosis distinct from that followed by organelles.

• MeSH
• aminokyseliny biosyntéza   MeSH
• Bacteria klasifikace   genetika   MeSH
• Betaproteobacteria genetika   MeSH
• fylogeneze MeSH
• Hemiptera genetika   mikrobiologie   fyziologie   MeSH
• molekulární sekvence - údaje MeSH
• přenos genů horizontální * MeSH
• stanovení celkové genové exprese MeSH
• symbióza * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

• MeSH
• Bacteria genetika   MeSH
• finanční podpora výzkumu jako téma MeSH
• přenos genů horizontální genetika   MeSH
• Ralstonia solanacearum genetika   MeSH
• Silene genetika   MeSH