scholarly journals The evolutionary origins of the cat attractant nepetalactone in catnip

2020 ◽  
Vol 6 (20) ◽  
pp. eaba0721 ◽  
Author(s):  
Benjamin R. Lichman ◽  
Grant T. Godden ◽  
John P. Hamilton ◽  
Lira Palmer ◽  
Mohamed O. Kamileen ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Genome Evolution ◽  
Gene Cluster ◽  
Phylogenetic Analyses ◽  
Chemical Diversity ◽  
Flowering Plant ◽  
Present Evidence ◽  
Metabolic Gene ◽  
Evolutionary Origins ◽  
Plant Chemical

Catnip or catmint (Nepeta spp.) is a flowering plant in the mint family (Lamiaceae) famed for its ability to attract cats. This phenomenon is caused by the compound nepetalactone, a volatile iridoid that also repels insects. Iridoids are present in many Lamiaceae species but were lost in the ancestor of the Nepetoideae, the subfamily containing Nepeta. Using comparative genomics, ancestral sequence reconstructions, and phylogenetic analyses, we probed the re-emergence of iridoid biosynthesis in Nepeta. The results of these investigations revealed mechanisms for the loss and subsequent re-evolution of iridoid biosynthesis in the Nepeta lineage. We present evidence for a chronology of events that led to the formation of nepetalactone biosynthesis and its metabolic gene cluster. This study provides insights into the interplay between enzyme and genome evolution in the origins, loss, and re-emergence of plant chemical diversity.

scholarly journals The protector within: Comparative genomics of APSE phages across aphids reveals rampant recombination and diverse toxin arsenals

2020 ◽  
Author(s):  
Jeff Rouïl ◽  
Emmanuelle Jousselin ◽  
Armelle Coeur d’acier ◽  
Corinne Cruaud ◽  
Alejandro Manzano-Marín
Keyword(s):  
Comparative Genomics ◽  
Genome Evolution ◽  
Phylogenetic Analyses ◽  
Insect Species ◽  
Parasitoid Wasps ◽  
Valuable Resource ◽  
Variable Regions ◽  
New Genes ◽  
Endosymbiotic Bacteria ◽  
Hamiltonella Defensa

ABSTRACTPhages can fundamentally alter the physiology and metabolism of their hosts. While ubiquitous in the bacterial world, they have seldom been described among endosymbiotic bacteria. One notable exception in the APSE phage that is found associated with the gammaproteobacterial Hamiltonella defensa, hosted by several insect species. This secondary facultative endosymbiont is not necessary for the survival of its hosts but can infect certain individuals or even whole populations. Its infection in aphids is often associated with protection against parasitoid wasps. This protective phenotype has actually been linked to the infection of the symbiont strain with an APSE, which carries a toxin cassette that varies among so-called ”types”. In the present work, we seek to expand our understanding of the diversity of APSE phages as well as the relations of their Hamiltonella hosts. For this, we assembled and annotated the full genomes of 16 APSE phages infecting Hamiltonella symbionts across 10 insect species. Molecular and phylogenetic analyses suggest that recombination has occurred repeatedly among lineages. Comparative genomics of the phage genomes revealed two variable regions that are useful for phage typing. Additionally, we find that mobile elements could play a role in the acquisition of new genes in the toxin cassette. Altogether, we provide an unprecedented view of APSE diversity and their genome evolution across aphids. This genomic investigation will provide a valuable resource for the design and interpretation of experiments aiming at understanding the protective phenotype these phages confer to their insect hosts.

scholarly journals The Protector within: Comparative Genomics of APSE Phages across Aphids Reveals Rampant Recombination and Diverse Toxin Arsenals

2020 ◽  
Vol 12 (6) ◽  
pp. 878-889
Author(s):  
Jeff Rouïl ◽  
Emmanuelle Jousselin ◽  
Armelle Coeur d’acier ◽  
Corinne Cruaud ◽  
Alejandro Manzano-Marín
Keyword(s):  
Comparative Genomics ◽  
Genome Evolution ◽  
Phylogenetic Analyses ◽  
Insect Species ◽  
Parasitoid Wasps ◽  
Valuable Resource ◽  
Variable Regions ◽  
New Genes ◽  
Endosymbiotic Bacteria ◽  
Hamiltonella Defensa

Abstract Phages can fundamentally alter the physiology and metabolism of their hosts. Although these phages are ubiquitous in the bacterial world, they have seldom been described among endosymbiotic bacteria. One notable exception is the APSE phage that is found associated with the gammaproteobacterial Hamiltonella defensa, hosted by several insect species. This secondary facultative endosymbiont is not necessary for the survival of its hosts but can infect certain individuals or even whole populations. Its infection in aphids is often associated with protection against parasitoid wasps. This protective phenotype has actually been linked to the infection of the symbiont strain with an APSE, which carries a toxin cassette that varies among so-called “types.” In the present work, we seek to expand our understanding of the diversity of APSE phages as well as the relations of their Hamiltonella hosts. For this, we assembled and annotated the full genomes of 16 APSE phages infecting Hamiltonella symbionts across ten insect species. Molecular and phylogenetic analyses suggest that recombination has occurred repeatedly among lineages. Comparative genomics of the phage genomes revealed two variable regions that are useful for phage typing. Additionally, we find that mobile elements could play a role in the acquisition of new genes in the toxin cassette. Altogether, we provide an unprecedented view of APSE diversity and their genome evolution across aphids. This genomic investigation will provide a valuable resource for the design and interpretation of experiments aiming at understanding the protective phenotype these phages confer to their insect hosts.

scholarly journals Rhodococcus comparative genomics reveals a phylogenomic-dependent non-ribosomal peptide synthetase distribution: insights into biosynthetic gene cluster connection to an orphan metabolite

2021 ◽  
Vol 7 (7) ◽  
Author(s):  
Agustina Undabarrena ◽  
Ricardo Valencia ◽  
Andrés Cumsille ◽  
Leonardo Zamora-Leiva ◽  
Eduardo Castro-Nallar ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Gene Cluster ◽  
Sequence Similarity ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Chemical Diversity ◽  
Comparative Genomic ◽  
Biosynthetic Gene ◽  
Content Type ◽  
Link Type

Natural products (NPs) are synthesized by biosynthetic gene clusters (BGCs), whose genes are involved in producing one or a family of chemically related metabolites. Advances in comparative genomics have been favourable for exploiting huge amounts of data and discovering previously unknown BGCs. Nonetheless, studying distribution patterns of novel BGCs and elucidating the biosynthesis of orphan metabolites remains a challenge. To fill this knowledge gap, our study developed a pipeline for high-quality comparative genomics for the actinomycete genus Rhodococcus , which is metabolically versatile, yet understudied in terms of NPs, leading to a total of 110 genomes, 1891 BGCs and 717 non-ribosomal peptide synthetases (NRPSs). Phylogenomic inferences showed four major clades retrieved from strains of several ecological habitats. BiG-SCAPE sequence similarity BGC networking revealed 44 unidentified gene cluster families (GCFs) for NRPS, which presented a phylogenomic-dependent evolution pattern, supporting the hypothesis of vertical gene transfer. As a proof of concept, we analysed in-depth one of our marine strains, Rhodococcus sp. H-CA8f, which revealed a unique BGC distribution within its phylogenomic clade, involved in producing a chloramphenicol-related compound. While this BGC is part of the most abundant and widely distributed NRPS GCF, corason analysis unveiled major differences regarding its genetic context, co-occurrence patterns and modularity. This BGC is composed of three sections, two well-conserved right/left arms flanking a very variable middle section, composed of nrps genes. The presence of two non-canonical domains in H-CA8f’s BGC may contribute to adding chemical diversity to this family of NPs. Liquid chromatography-high resolution MS and dereplication efforts retrieved a set of related orphan metabolites, the corynecins, which to our knowledge are reported here for the first time in Rhodococcus . Overall, our data provide insights to connect BGC uniqueness with orphan metabolites, by revealing key comparative genomic features supported by models of BGC distribution along phylogeny.

scholarly journals Evolutionary Origins of the Fumonisin Secondary Metabolite Gene Cluster in Fusarium verticillioides and Aspergillus niger

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Nora Khaldi ◽  
Kenneth H. Wolfe
Keyword(s):  
Comparative Genomics ◽  
Aspergillus Niger ◽  
Gene Cluster ◽  
Secondary Metabolite ◽  
Horizontal Transfer ◽  
Fusarium Verticillioides ◽  
Gene Clusters ◽  
Evolutionary Origins ◽  
Species Specific ◽  
Secondary Metabolite Gene Cluster

The secondary metabolite gene clusters of euascomycete fungi are among the largest known clusters of functionally related genes in eukaryotes. Most of these clusters are species specific or genus specific, and little is known about how they are formed during evolution. We used a comparative genomics approach to study the evolutionary origins of a secondary metabolite cluster that synthesizes a polyketide derivative, namely, the fumonisin (FUM) cluster of Fusarium verticillioides, and that of Aspergillus niger another fumonisin (fumonisin B) producing species. We identified homologs in other euascomycetes of the Fusarium verticillioides FUM genes and their flanking genes. We discuss four models for the origin of the FUM cluster in Fusarium verticillioides and argue that two of these are plausible: (i) assembly by relocation of initially scattered genes in a recent Fusarium verticillioides; or (ii) horizontal transfer of the FUM cluster from a distantly related Sordariomycete species. We also propose that the FUM cluster was horizontally transferred into Aspergillus niger, most probably from a Sordariomycete species.

scholarly journals Exceptional preservation of mid-Cretaceous marine arthropods and the evolution of novel forms via heterochrony

2019 ◽  
Vol 5 (4) ◽  
pp. eaav3875 ◽  
Author(s):  
J. Luque ◽  
R. M. Feldmann ◽  
O. Vernygora ◽  
C. E. Schweitzer ◽  
C. B. Cameron ◽  
...  
Keyword(s):  
United States ◽  
Early Cretaceous ◽  
Phylogenetic Analyses ◽  
The United States ◽  
Body Plan ◽  
Compound Eyes ◽  
Exceptional Preservation ◽  
Evolutionary Origins ◽  
Morphological Transformations ◽  
Active Swimming

Evolutionary origins of novel forms are often obscure because early and transitional fossils tend to be rare, poorly preserved, or lack proper phylogenetic contexts. We describe a new, exceptionally preserved enigmatic crab from the mid-Cretaceous of Colombia and the United States, whose completeness illuminates the early disparity of the group and the origins of novel forms. Its large and unprotected compound eyes, small fusiform body, and leg-like mouthparts suggest larval trait retention into adulthood via heterochronic development (pedomorphosis), while its large oar-like legs represent the earliest known adaptations in crabs for active swimming. Our phylogenetic analyses, including representatives of all major lineages of fossil and extant crabs, challenge conventional views of their evolution by revealing multiple convergent losses of a typical “crab-like” body plan since the Early Cretaceous. These parallel morphological transformations may be associated with repeated invasions of novel environments, including the pelagic/necto-benthic zone in this pedomorphic chimera crab.

scholarly journals Comparative Genomics and Phylogenetic Analyses Suggest Several Novel Species within the Genus Clavibacter, Including Nonpathogenic Tomato-Associated Strains

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
Ebrahim Osdaghi ◽  
Touraj Rahimi ◽  
S. Mohsen Taghavi ◽  
Maryam Ansari ◽  
Sadegh Zarei ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Comparative Genomics ◽  
Plant Pathogens ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Sensu Stricto ◽  
Bacterial Canker ◽  
Agricultural Crops ◽  
Content Type ◽  
Canker Disease

ABSTRACT Members of the genus Clavibacter are economically important bacterial plant pathogens infecting a set of diverse agricultural crops (e.g., alfalfa, corn, potato, tomato, and wheat). Tomato-associated Clavibacter sp. strains account for a great portion of the genetic diversity of the genus, and C. michiganensis sensu stricto (formerly C. michiganensis subsp. michiganensis), causing bacterial canker disease, is considered one of the most destructive seed-borne agents for the crop worldwide. However, current taxonomic descriptions of the genus do not reflect the existing diversity of the strains, resulting in unsatisfactory results in quarantine surveys for the pathogens. In this study, we used all the available genome sequences of Clavibacter sp. strains, including the type strains of newly described subspecies, to provide precise insight into the diversity of tomato-associated members of the genus and further clarify the taxonomic status of the strains using genotypic and phenotypic features. The results of phylogenetic analyses revealed the existence of nine hypothetical new species among the investigated strains. None of the three new subspecies (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) is included within the tomato-pathogenic C. michiganensis sensu stricto lineage. Although comparative genomics revealed the lack of chp and tomA pathogenicity determinant gene clusters in the nonpathogenic strains, a number of pathogenicity-related genes were noted to be present in all the strains regardless of their pathogenicity characteristics. Altogether, our results indicate a need for a formal taxonomic reconsideration of tomato-associated Clavibacter sp. strains to facilitate differentiation of the lineages in quarantine inspections. IMPORTANCE Clavibacter spp. are economically important bacterial plant pathogens infecting a set of diverse agricultural crops, such as alfalfa, corn, pepper, potato, tomato, and wheat. A number of plant-pathogenic members of the genus (e.g., C. michiganensis sensu stricto and C. sepedonicus, infecting tomato and potato plants, respectively) are included in the A2 (high-risk) list of quarantine pathogens by the European and Mediterranean Plant Protection Organization (EPPO). Although tomato-associated members of Clavibacter spp. account for a significant portion of the genetic diversity in the genus, only the strains belonging to C. michiganensis sensu stricto (formerly C. michiganensis subsp. michiganensis) cause bacterial canker disease of tomato and are subjected to the quarantine inspections. Hence, discrimination between the pathogenic and nonpathogenic Clavibacter sp. strains associated with tomato seeds and transplants plays a pivotal role in the accurate detection and cost-efficient management of the disease. On the other hand, detailed information on the genetic contents of different lineages of the genus would lead to the development of genome-informed specific detection techniques. In this study, we have provided an overview of the phylogenetic and genomic differences between the pathogenic and nonpathogenic tomato-associated Clavibacter sp. strains. We also noted that the taxonomic status of newly introduced subspecies of C. michiganensis (i.e., C. michiganensis subsp. californiensis, C. michiganensis subsp. chilensis, and C. michiganensis subsp. phaseoli) should be reconsidered.

scholarly journals The C-Fern (Ceratopteris richardii) genome: insights into plant genome evolution with the first partial homosporous fern genome assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
D. Blaine Marchant ◽  
Emily B. Sessa ◽  
Paul G. Wolf ◽  
Kweon Heo ◽  
W. Brad Barbazuk ◽  
...  
Keyword(s):  
Genome Evolution ◽  
Green Plant ◽  
Land Plant ◽  
Plant Genome ◽  
Flowering Plant ◽  
Ceratopteris Richardii ◽  
Repeat Elements ◽  
Homosporous Fern ◽  
Homosporous Ferns ◽  
Large Genomes

AbstractFerns are notorious for possessing large genomes and numerous chromosomes. Despite decades of speculation, the processes underlying the expansive genomes of ferns are unclear, largely due to the absence of a sequenced homosporous fern genome. The lack of this crucial resource has not only hindered investigations of evolutionary processes responsible for the unusual genome characteristics of homosporous ferns, but also impeded synthesis of genome evolution across land plants. Here, we used the model fern species Ceratopteris richardii to address the processes (e.g., polyploidy, spread of repeat elements) by which the large genomes and high chromosome numbers typical of homosporous ferns may have evolved and have been maintained. We directly compared repeat compositions in species spanning the green plant tree of life and a diversity of genome sizes, as well as both short- and long-read-based assemblies of Ceratopteris. We found evidence consistent with a single ancient polyploidy event in the evolutionary history of Ceratopteris based on both genomic and cytogenetic data, and on repeat proportions similar to those found in large flowering plant genomes. This study provides a major stepping-stone in the understanding of land plant evolutionary genomics by providing the first homosporous fern reference genome, as well as insights into the processes underlying the formation of these massive genomes.

Comparative genomics reveals dynamic genome evolution in host specialist ectomycorrhizal fungi

2020 ◽  
Author(s):  
Lotus A. Lofgren ◽  
Nhu H. Nguyen ◽  
Rytas Vilgalys ◽  
Joske Ruytinx ◽  
Hui‐Ling Liao ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Genome Evolution ◽  
Ectomycorrhizal Fungi ◽  
Dynamic Genome

scholarly journals A Rare Thioquinolobactin Siderophore Present in a Bioactive Pseudomonas sp. DTU12.1

2019 ◽  
Vol 11 (12) ◽  
pp. 3529-3533
Author(s):  
Pavelas Sazinas ◽  
Morten Lindqvist Hansen ◽  
May Iren Aune ◽  
Marie Højmark Fischer ◽  
Lars Jelsbak
Keyword(s):  
Gene Cluster ◽  
Secondary Metabolite ◽  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Plant Pathogens ◽  
Gene Clusters ◽  
Fungal Species ◽  
Antagonistic Activity ◽  
Evolutionary Origins

Abstract Many of the soil-dwelling Pseudomonas species are known to produce secondary metabolite compounds, which can have antagonistic activity against other microorganisms, including important plant pathogens. It is thus of importance to isolate new strains of Pseudomonas and discover novel or rare gene clusters encoding bioactive products. In an effort to accomplish this, we have isolated a bioactive Pseudomonas strain DTU12.1 from leaf-covered soil in Denmark. Following genome sequencing with Illumina and Oxford Nanopore technologies, we generated a complete genome sequence with the length of 5,943,629 base pairs. The DTU12.1 strain contained a complete gene cluster for a rare thioquinolobactin siderophore, which was previously described as possessing bioactivity against oomycetes and several fungal species. We placed the DTU12.1 strain within Pseudomonas gessardii subgroup of fluorescent pseudomonads, where it formed a distinct clade with other Pseudomonas strains, most of which also contained a complete thioquinolobactin gene cluster. Only two other Pseudomonas strains were found to contain the gene cluster, though they were present in a different phylogenetic clade and were missing a transcriptional regulator of the whole cluster. We show that having the complete genome sequence and establishing phylogenetic relationships with other strains can enable us to start evaluating the distribution and evolutionary origins of secondary metabolite clusters.

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