scholarly journals Horizontal gene transfer of a unique nif island drives convergent evolution of free-living N2-fixing Bradyrhizobium

2021 ◽  
Author(s):  
Jinjin Tao ◽  
Sishuo Wang ◽  
Tianhua Liao ◽  
Haiwei Luo
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Agricultural Research ◽  
Current Knowledge ◽  
Gene Clusters ◽  
Soil Samples ◽  
Genomic Context ◽  
Free Living ◽  
Phylogenomic Analyses ◽  
Conserved Gene

SummaryThe alphaproteobacterial genus Bradyrhizobium has been best known as N2-fixing members that nodulate legumes, supported by the nif and nod gene clusters. Recent environmental surveys show that Bradyrhizobium represents one of the most abundant free-living bacterial lineages in the world’s soils. However, our understanding of Bradyrhizobium comes largely from symbiotic members, biasing the current knowledge of their ecology and evolution. Here, we report the genomes of 88 Bradyrhizobium strains derived from diverse soil samples, including both nif-carrying and non-nif-carrying free-living (nod free) members. Phylogenomic analyses of these and 252 publicly available Bradyrhizobium genomes indicate that nif-carrying free-living members independently evolved from symbiotic ancestors (carrying both nif and nod) multiple times. Intriguingly, the nif phylogeny shows that all nif-carrying free-living members comprise a cluster which branches off earlier than most symbiotic lineages. These results indicate that horizontal gene transfer (HGT) promotes nif expansion among the free-living Bradyrhizobium and that the free-living nif cluster represents a more ancestral version compared to that in symbiotic lineages. Further evidence for this rampant HGT is that the nif in free-living members consistently co-locate with several important genes involved in coping with oxygen tension which are missing from symbiotic members, and that while in free-living Bradyrhizobium nif and the co-locating genes show a highly conserved gene order, they each have distinct genomic context. Given the dominance of Bradyrhizobium in world’s soils, our findings have implications for global nitrogen cycles and agricultural research.

scholarly journals Phylogenomic Analyses of Non-Dikarya Fungi Supports Horizontal Gene Transfer Driving Diversification of Secondary Metabolism in the Amphibian Gastrointestinal Symbiont, Basidiobolus

2020 ◽  
Vol 10 (9) ◽  
pp. 3417-3433
Author(s):  
Javier F Tabima ◽  
Ian A Trautman ◽  
Ying Chang ◽  
Yan Wang ◽  
Stephen Mondo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Secondary Metabolism ◽  
Gene Clusters ◽  
Biologically Active ◽  
Constitutive Gene Expression ◽  
Gut Symbionts ◽  
Phylogenomic Analyses ◽  
Siderophore Activity

Abstract Research into secondary metabolism (SM) production by fungi has resulted in the discovery of diverse, biologically active compounds with significant medicinal applications. The fungi rich in SM production are taxonomically concentrated in the subkingdom Dikarya, which comprises the phyla Ascomycota and Basidiomycota. Here, we explore the potential for SM production in Mucoromycota and Zoopagomycota, two phyla of nonflagellated fungi that are not members of Dikarya, by predicting and identifying core genes and gene clusters involved in SM. The majority of non-Dikarya have few genes and gene clusters involved in SM production except for the amphibian gut symbionts in the genus Basidiobolus. Basidiobolus genomes exhibit an enrichment of SM genes involved in siderophore, surfactin-like, and terpene cyclase production, all these with evidence of constitutive gene expression. Gene expression and chemical assays also confirm that Basidiobolus has significant siderophore activity. The expansion of SMs in Basidiobolus are partially due to horizontal gene transfer from bacteria, likely as a consequence of its ecology as an amphibian gut endosymbiont.

scholarly journals Phylogenomic analyses of non-Dikarya fungi supports horizontal gene transfer driving diversification of secondary metabolism in the amphibian gastrointestinal symbiont, Basidiobolus

2020 ◽  
Author(s):  
Javier Felipe Tabima ◽  
Ian A. Trautman ◽  
Ying Chang ◽  
Yan Wang ◽  
Stephen J. Mondo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Secondary Metabolism ◽  
Gene Clusters ◽  
Biologically Active ◽  
Constitutive Gene Expression ◽  
Gut Symbionts ◽  
Phylogenomic Analyses ◽  
Siderophore Activity

Research into secondary metabolism (SM) production by fungi has resulted in the discovery of diverse, biologically active compounds with significant medicinal applications. However, the fungi rich in SM production are taxonomically restricted to Dikarya, two phyla of Kingdom Fungi, Ascomycota and Basidiomycota. Here, we explore the potential for SM production in Mucoromycota and Zoopagomycota, two phyla of nonflagellated fungi that are not members of Dikarya, by predicting and identifying core genes and gene clusters involved in SM. The majority of non-Dikarya have few genes and gene clusters involved in SM production except for the amphibian gut symbionts in the genus Basidiobolus. Basidiobolus genomes exhibit an enrichment of SM genes involved in siderophore, surfactin-like, and terpene cyclase production, all these with evidence of constitutive gene expression. Gene expression and chemical assays confirm that Basidiobolus has significant siderophore activity. The expansion of SMs in Basidiobolus are partially due to horizontal gene transfer from bacteria, likely as a consequence of its ecology as an amphibian gut endosymbiont.

Horizontal gene transfer among microorganisms in food: Current knowledge and future perspectives

2014 ◽  
Vol 42 ◽  
pp. 232-243 ◽  
Author(s):  
Franca Rossi ◽  
Lucia Rizzotti ◽  
Giovanna E. Felis ◽  
Sandra Torriani
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Current Knowledge ◽  
Future Perspectives

Modern View on Enterococcus faecalis and Enterococcus faecium Resistance Mechanisms to Antibiotics

2021 ◽  
Vol 65 (11-12) ◽  
pp. 38-48
Author(s):  
T. S. Komenkova ◽  
E. A. Zaitseva
Keyword(s):  
Clinical Practice ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Current Knowledge ◽  
Common Species ◽  
Resistance Mechanisms ◽  
Causative Agents ◽  
Level Resistance

Enterococci are currently becoming one of the major causative agents of various infectious diseases. Enterococcus faecalis and E.faecium are the most common species causing enterococcal infections. Both species exhibit natural low-level resistance to aminoglycosides, cephalosporins, quinolones, clindamycin, and co-trimoxazole. In addition, the peculiarities of their genome make it easy to acquire resistance to other antibiotics widely used in clinical practice, through mutations or by horizontal gene transfer. The review represents current knowledge about the mechanisms of enterococcal resistance to the most commonly used antibiotics.

scholarly journals Many nonuniversal archaeal ribosomal proteins are found in conserved gene clusters

Archaea ◽  
2009 ◽  
Vol 2 (4) ◽  
pp. 241-251 ◽  
Author(s):  
Jiachen Wang ◽  
Indrani Dasgupta ◽  
George E. Fox
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Proteins ◽  
Gene Clusters ◽  
Cellular Systems ◽  
Gene Content ◽  
Genomic Context ◽  
Gene Encoding ◽  
Cellular Processes ◽  
Conserved Gene

The genomic associations of the archaeal ribosomal proteins, (r-proteins), were examined in detail. The archaeal versions of the universal r-protein genes are typically in clusters similar or identical and to those found in bacteria. Of the 35 nonuniversal archaeal r-protein genes examined, the gene encoding L18e was found to be associated with the conservedL13cluster, whereas the genes for S4e, L32e and L19e were found in the archaeal version of thespcoperon. Eleven nonuniversal protein genes were not associated with any common genomic context. Of the remaining 19 protein genes, 17 were convincingly assigned to one of 10 previously unrecognized gene clusters. Examination of the gene content of these clusters revealed multiple associations with genes involved in the initiation of protein synthesis, transcription or other cellular processes. The lack of such associations in the universal clusters suggests that initially the ribosome evolved largely independently of other processes. More recently it likely has evolved in concert with other cellular systems. It was also verified that a second copy of the gene encoding L7ae found in some bacteria is actually a homolog of the gene encoding L30e and should be annotated as such.

scholarly journals Repeated horizontal gene transfer of GALactose metabolism genes violates Dollo’s law of irreversible loss

2020 ◽  
Author(s):  
Max A. B. Haase ◽  
Jacek Kominek ◽  
Dana A. Opulente ◽  
Xing-Xing Shen ◽  
Abigail L. LaBella ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Complex Traits ◽  
Galactose Metabolism ◽  
History Of ◽  
Dollo’S Law ◽  
Ancestral States ◽  
Phylogenomic Analyses ◽  
Galactose Utilization ◽  
Utilization Pathway

AbstractDollo’s law posits that evolutionary losses are irreversible, thereby narrowing the potential paths of evolutionary change. While phenotypic reversals to ancestral states have been observed, little is known about their underlying genetic causes. The genomes of budding yeasts have been shaped by extensive reductive evolution, such as reduced genome sizes and the losses of metabolic capabilities. However, the extent and mechanisms of trait reacquisition after gene loss in yeasts have not been thoroughly studied. Here, through phylogenomic analyses, we reconstructed the evolutionary history of the yeast galactose utilization pathway and observed widespread and repeated losses of the ability to utilize galactose, which occurred concurrently with the losses of GALactose (GAL) utilization genes. Unexpectedly, we detected three galactose-utilizing lineages that were deeply embedded within clades that underwent ancient losses of galactose utilization. We show that at least two, and possibly three, lineages reacquired the GAL pathway via yeast-to-yeast horizontal gene transfer. Our results show how trait reacquisition can occur tens of millions of years after an initial loss via horizontal gene transfer from distant relatives. These findings demonstrate that the losses of complex traits and even whole pathways are not always evolutionary dead-ends, highlighting how reversals to ancestral states can occur.

scholarly journals Horizontal transfer in bacterial Methionyl tRNA synthetase is very common shown by Genus and phyla level phylogenetic analysis.

2016 ◽  
Author(s):  
Prabhakar Ghorpade ◽  
Avinash Pange ◽  
Bhaskar Sharma
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Single Copy ◽  
Trna Synthetase ◽  
Species Tree ◽  
Large Trees ◽  
Conserved Gene ◽  
Methionyl Trna Synthetase ◽  
Informational Gene

Methionyl tRNA synthetase is single copy informational gene in Salmonella typhimurium. Informational genes are more conserved than operational genes. In this study we had analyzed HGT events within MetG sequences of different bacterial genera. A species tree based on 16srRNA sequences of the same genus was drawn evaluated against the generally accepted species tree of the bacteria. MetG phylogenetic tree was evaluated against the 16srRNAS tree and HGT event identified. Similarly phyla trees were made and HGT event identified. 24 HGT events were identified between genus and 11 within phyla. MetG is a considered as conserved gene finding so many HGT event in this gene indicate that horizontal gene transfer is very common in this gene. Manual tree making for phyla could help to understand phylogenetic relationships between very large trees.

scholarly journals Massive Gene Flux Drives Genome Diversity between Sympatric Streptomyces Conspecifics

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Abdoul-Razak Tidjani ◽  
Jean-Noël Lorenzi ◽  
Maxime Toussaint ◽  
Erwin van Dijk ◽  
Delphine Naquin ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Public Goods ◽  
Significant Proportion ◽  
Gene Clusters ◽  
Recent Common Ancestor ◽  
Natural Soil ◽  
Gene Pools ◽  
Bacterial Gene ◽  
Integrative And Conjugative Elements

ABSTRACT In this work, by comparing genomes of closely related individuals of Streptomyces isolated at a spatial microscale (millimeters or centimeters), we investigated the extent and impact of horizontal gene transfer in the diversification of a natural Streptomyces population. We show that despite these conspecific strains sharing a recent common ancestor, all harbored significantly different gene contents, implying massive and rapid gene flux. The accessory genome of the strains was distributed across insertion/deletion events (indels) ranging from one to several hundreds of genes. Indels were preferentially located in the arms of the linear chromosomes (ca. 12 Mb) and appeared to form recombination hot spots. Some of them harbored biosynthetic gene clusters (BGCs) whose products confer an inhibitory capacity and may constitute public goods that can favor the cohesiveness of the bacterial population. Moreover, a significant proportion of these variable genes were either plasmid borne or harbored signatures of actinomycete integrative and conjugative elements (AICEs). We propose that conjugation is the main driver for the indel flux and diversity in Streptomyces populations. IMPORTANCE Horizontal gene transfer is a rapid and efficient way to diversify bacterial gene pools. Currently, little is known about this gene flux within natural soil populations. Using comparative genomics of Streptomyces strains belonging to the same species and isolated at microscale, we reveal frequent transfer of a significant fraction of the pangenome. We show that it occurs at a time scale enabling the population to diversify and to cope with its changing environment, notably, through the production of public goods.

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