Horizontal gene transfer and the rock record: comparative genomics of phylogenetically distant bacteria that induce wrinkle structure formation in modern sediments

Geobiology ◽  
2014 ◽  
Vol 12 (2) ◽  
pp. 119-132 ◽  
Author(s):  
B. E. Flood ◽  
J. V. Bailey ◽  
J. F. Biddle
Keyword(s):  
Comparative Genomics ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Structure Formation ◽  
Rock Record

scholarly journals A Cotransformation Method To Identify a Restriction-Modification Enzyme That Reduces Conjugation Efficiency inCampylobacter jejuni

2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Ximin Zeng ◽  
Zuowei Wu ◽  
Qijing Zhang ◽  
Jun Lin
Keyword(s):  
Comparative Genomics ◽  
Heat Shock ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Campylobacter Jejuni ◽  
Selection Marker ◽  
Sequencing Analysis ◽  
Content Type ◽  
Restriction Modification ◽  
Modification Enzyme

ABSTRACTConjugation is an important mechanism for horizontal gene transfer inCampylobacter jejuni, the leading cause of human bacterial gastroenteritis in developed countries. However, to date, the factors that significantly influence conjugation efficiency inCampylobacterspp. are still largely unknown. Given that multiple recombinant loci could independently occur within one recipient cell during natural transformation, the genetic materials from a high-frequency conjugation (HFC)C. jejunistrain may be cotransformed with a selection marker into a low-frequency conjugation (LFC) recipient strain, creating new HFC transformants suitable for the identification of conjugation factors using a comparative genomics approach. To test this, an erythromycin resistance selection marker was created in an HFCC. jejunistrain; subsequently, the DNA of this strain was naturally transformed into NCTC 11168, an LFCC. jejunistrain, leading to the isolation of NCTC 11168-derived HFC transformants. Whole-genome sequencing analysis and subsequent site-directed mutagenesis identified Cj1051c, a putative restriction-modification enzyme (akaCjeI) that could drastically reduce the conjugation efficiency of NCTC 11168 (>5,000-fold). Chromosomal complementation of three diverse HFCC. jejunistrains with CjeI also led to a dramatic reduction in conjugation efficiency (∼1,000-fold). The purified recombinant CjeI could effectively digest theEscherichia coli-derived shuttle vector pRY107. The endonuclease activity of CjeI was abolished upon short heat shock treatment at 50°C, which is consistent with our previous observation that heat shock enhanced conjugation efficiency inC. jejuni. Together, in this study, we successfully developed and utilized a unique cotransformation strategy to identify a restriction-modification enzyme that significantly influences conjugation efficiency inC. jejuni.IMPORTANCEConjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance.Campylobacter jejuni, the leading foodborne bacterial organism, displays significant strain diversity due to horizontal gene transfer; however, the molecular components influencing conjugation efficiency inC. jejuniare still largely unknown. In this study, we developed a cotransformation strategy for comparative genomics analysis and successfully identified a restriction-modification enzyme that significantly influences conjugation efficiency inC. jejuni. The new cotransformation strategy developed in this study is also expected to be broadly applied in other naturally competent bacteria for functional comparative genomics research.

scholarly journals Horizontal transfer of the n-TASE gene cluster in Burkholderia seminalis TC3.4.2R3 inferred from phylogenetic and molecular methods

2021 ◽  
Author(s):  
Sarina Tsui ◽  
Welington Luiz Araújo
Keyword(s):  
Comparative Genomics ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Horizontal Transfer ◽  
Horizontal Gene Transfer Event ◽  
Donor Strain ◽  
Biotechnological Applications ◽  
Transfer Event ◽  
Species Phylogeny ◽  
Homologous Genes

Abstract This study describes the n-TASE cluster in Burkholderia seminalis TC3.4.2R3, which was present in B. contaminans (CP046609.1), but absent in other related Burkholderia species. Phylogeny, comparative genomics and molecular analysis indicated it is not common to B. seminalis species, presenting similarity with homologous genes presents Aquamicrobium sp. SK-2 and B. contaminans LMG23361, probably acquired by an HGT (Horizontal Gene Transfer) event. It was not possible to determine which was the most likely donor strain of the n-TASE cluster. The HGT event did not occur in all strains of the Bcc group, nor in the B. seminalis, but it did occur punctually in the strain B. seminalis TC34.2R3. It has a correlation in biotechnological applications related processes. Aiming at understanding the involvement of the n-TASE cluster in the interaction of this bacterium in the environment, genes in this cluster will be inactivated, next.

scholarly journals Molecular Dating of the Emergence of Anaerobic Rumen Fungi and the Impact of Laterally Acquired Genes

mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Yan Wang ◽  
Noha H. Youssef ◽  
Matthew Brian Couger ◽  
Radwa A. Hanafy ◽  
Mostafa S. Elshahed ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Plant Biomass ◽  
Gut Bacteria ◽  
Molecular Dating ◽  
Polysaccharide Lyase ◽  
Animal Hosts ◽  
Herbivorous Mammals ◽  
Lineage Specific Genes

ABSTRACT The anaerobic gut fungi (AGF), or Neocallimastigomycota, inhabit the rumen and alimentary tract of herbivorous mammals, where they play important roles in the degradation of plant fiber. Comparative genomic and phylogenomic analyses of the AGF have long been hampered by their fastidious growth condition, as well as their large (up to 200 Mb) and AT-biased (78 to 84%) genomes. We sequenced 21 AGF transcriptomes and combined them with 5 available AGF genome sequences to explore their evolutionary relationships, time their divergence, and characterize gene gain/loss patterns associated with their evolution. We estimate that the most recent common ancestor of the AGF diverged 66 (±10) million years ago, a time frame that coincides with the evolution of grasses (Poaceae), as well as the mammalian transition from insectivory to herbivory. The concordance of independent estimations suggests that AGF have been important in shaping the success of mammalian herbivory transition by improving the efficiency of energy acquisition from recalcitrant plant materials. Comparative genomics identified multiple lineage-specific genes in the AGF, two of which were acquired from rumen gut bacteria and animal hosts via horizontal gene transfer (HGT). A third AGF domain, plant-like polysaccharide lyase, represents a novel gene in fungi that potentially aids AGF to degrade pectin. Analysis of genomic and transcriptomic sequences confirmed both the presence and expression of these lineage-specific genes in nearly all AGF clades. These genetic elements may contribute to the exceptional abilities of AGF to degrade plant biomass and enable metabolism of the rumen microbes and animal hosts. IMPORTANCE Anaerobic fungi living in the rumen of herbivorous mammals possess an extraordinary ability to degrade plant biomass. We examined the origin and genomic composition of these poorly characterized anaerobic gut fungi using both transcriptome and genomic data. Phylogenomics and molecular dating analyses found remarkable concurrence of the divergence times of the rumen fungi, the forage grasses, and the dietary shift of ancestral mammals from primarily insectivory to herbivory. Comparative genomics identified unique machinery in these fungi to utilize plant polysaccharides. The rumen fungi were also identified with the ability to code for three protein domains with putative functions in plant pectin degradation and microbial defense, which were absent from all other fungal organisms (examined over 1,000 fungal genomes). Two of these domains were likely acquired from rumen gut bacteria and animal hosts separately via horizontal gene transfer. The third one is a plant-like polysaccharide lyase, representing a unique fungal enzyme with potential pectin breakdown abilities.

scholarly journals Genome-Wide Analysis of PL7 Alginate Lyases in the Genus Zobellia

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2387
Author(s):  
Nadezhda Chernysheva ◽  
Evgeniya Bystritskaya ◽  
Galina Likhatskaya ◽  
Olga Nedashkovskaya ◽  
Marina Isaeva
Keyword(s):  
Comparative Genomics ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gene Duplication ◽  
Genetic Variability ◽  
Structure Modeling ◽  
Genome Wide Analysis ◽  
Polysaccharide Lyase ◽  
Genome Wide ◽  
Alginate Lyases

We carried out a detailed investigation of PL7 alginate lyases across the Zobellia genus. The main findings were obtained using the methods of comparative genomics and spatial structure modeling, as well as a phylogenomic approach. Initially, in order to elucidate the alginolytic potential of Zobellia, we calculated the content of polysaccharide lyase (PL) genes in each genome. The genus-specific PLs were PL1, PL6, PL7 (the most abundant), PL14, PL17, and PL40. We revealed that PL7 belongs to subfamilies 3, 5, and 6. They may be involved in local and horizontal gene transfer and gene duplication processes. Most likely, an individual evolution of PL7 genes promotes the genetic variability of the Alginate Utilization System across Zobellia. Apparently, the PL7 alginate lyases may acquire a sub-functionalization due to diversification between in-paralogs.

scholarly journals Evidence for loss and adaptive reacquisition of alcoholic fermentation in an early-derived fructophilic yeast lineage

2017 ◽  
Author(s):  
Carla Gonçalves ◽  
Jennifer H. Wisecaver ◽  
Madalena Salema-Oom ◽  
Maria José Leandro ◽  
Xing-Xing Shen ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Carbon Metabolism ◽  
Alcoholic Fermentation ◽  
Carbon Sources ◽  
Central Carbon Metabolism ◽  
High Sugar ◽  
Central Carbon ◽  
Adaptive Nature

AbstractFructophily is a rare trait that consists in the preference for fructose over other carbon sources. Here we show that in a yeast lineage (theWickerhamiella/Starmerella, W/S clade) formed by fructophilic species thriving in the floral niche, the acquisition of fructophily is part of a wider process of adaptation of central carbon metabolism to the high sugar environment. Coupling comparative genomics with biochemical and genetic approaches, we show that the alcoholic fermentation pathway was profoundly remodeled in the W/S clade, as genes required for alcoholic fermentation were lost and subsequently re-acquired from bacteria through horizontal gene transfer. We further show that the reinstated fermentative pathway is functional and that an enzyme required for sucrose assimilation is also of bacterial origin, reinforcing the adaptive nature of the genetic novelties identified in the W/S clade. This work shows how even central carbon metabolism can be remodeled by a surge of HGT events.

scholarly journals Genome-wide estimation of recombination, mutation and positive selection enlightens diversification drivers of Mycobacterium bovis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana C. Reis ◽  
Mónica V. Cunha
Keyword(s):  
Comparative Genomics ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Positive Selection ◽  
Population Expansion ◽  
Whole Genome Sequence ◽  
General Notion ◽  
Terrestrial Mammals ◽  
Evolutionary Forces ◽  
Recombination System

AbstractGenome sequencing has reinvigorated the infectious disease research field, shedding light on disease epidemiology, pathogenesis, host–pathogen interactions and also evolutionary processes exerted upon pathogens. Mycobacterium tuberculosis complex (MTBC), enclosing M. bovis as one of its animal-adapted members causing tuberculosis (TB) in terrestrial mammals, is a paradigmatic model of bacterial evolution. As other MTBC members, M. bovis is postulated as a strictly clonal, slowly evolving pathogen, with apparently no signs of recombination or horizontal gene transfer. In this work, we applied comparative genomics to a whole genome sequence (WGS) dataset composed by 70 M. bovis from different lineages (European and African) to gain insights into the evolutionary forces that shape genetic diversification in M. bovis. Three distinct approaches were used to estimate signs of recombination. Globally, a small number of recombinant events was identified and confirmed by two independent methods with solid support. Still, recombination reveals a weaker effect on M. bovis diversity compared with mutation (overall r/m = 0.037). The differential r/m average values obtained across the clonal complexes of M. bovis in our dataset are consistent with the general notion that the extent of recombination may vary widely among lineages assigned to the same taxonomical species. Based on this work, recombination in M. bovis cannot be excluded and should thus be a topic of further effort in future comparative genomics studies for which WGS of large datasets from different epidemiological scenarios across the world is crucial. A smaller M. bovis dataset (n = 42) from a multi-host TB endemic scenario was then subjected to additional analyses, with the identification of more than 1,800 sites wherein at least one strain showed a single nucleotide polymorphism (SNP). The majority (87.1%) was located in coding regions, with the global ratio of non-synonymous upon synonymous alterations (dN/dS) exceeding 1.5, suggesting that positive selection is an important evolutionary force exerted upon M. bovis. A higher percentage of SNPs was detected in genes enriched into “lipid metabolism”, “cell wall and cell processes” and “intermediary metabolism and respiration” functional categories, revealing their underlying importance in M. bovis biology and evolution. A closer look on genes prone to horizontal gene transfer in the MTBC ancestor and included in the 3R (DNA repair, replication and recombination) system revealed a global average negative value for Taijima’s D neutrality test, suggesting that past selective sweeps and population expansion after a recent bottleneck remain as major evolutionary drivers of the obligatory pathogen M. bovis in its struggle with the host.

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