First Report of the Gastropod-Killing Nematode, Phasmarhabditis californica, in Washington State, U.S.A.

, a commercially available biological control agent in England, Scotland, and Wales (Nemaslug 2.0 ®), was discovered for the first time in Washington State during 2022. Nematodes were recovered from the invasive gastropods , and sp.

Genomic Analyses of , A Quarantine Agricultural Pathogen in Idaho.

is among the most significant plant-parasitic nematodes worldwide, causing major damage to potato production. Since it was discovered in Idaho in 2006, eradication efforts have aimed to contain and eradicate through phytosanitary action and soil fumigation. In this study, we investigated genome-wide patterns of genetic variation across Idaho fields to evaluate whether the infestation resulted from a single or multiple introduction(s) and to investigate potential evolutionary responses since the time of infestation.

Phylogenetic evidence for the invasion of a commercialized European Phasmarhabditis hermaphrodita lineage into North America and New Zealand.

Biological control (biocontrol) as a component of pest management strategies reduces reliance on synthetic chemicals, and seemingly offers a natural approach that minimizes environmental impact. However, introducing a new organism to new environments as a classical biocontrol agent can have broad and unanticipated biodiversity effects and conservation consequences. Nematodes are currently used in a variety of commercial biocontrol applications, including the use of Phasmarhabditis hermaphrodita as an agent targeting pest slug and snail species.

First report of molecular characterization and phylogeny of Hall, 1916 (Nematoda: Trichuridae).

Because species of are morphologically similar and ranges of host preference are variable, using molecular data to evaluate species delineations is essential for properly quantifying biodiversity of and relationships within Trichuridae. has been reported from spp. (Rodentia: Geomyidae, 'pocket gophers') hosts based on morphological features alone.

Mitochondrial DNA Variation and Selfish Propagation Following Experimental Bottlenecking in Two Distantly Related Isolates.

Understanding mitochondrial DNA (mtDNA) evolution and inheritance has broad implications for animal speciation and human disease models. However, few natural models exist that can simultaneously represent mtDNA transmission bias, mutation, and copy number variation. Certain isolates of the nematode harbor large, naturally-occurring mtDNA deletions of several hundred basepairs affecting the () gene that can be functionally detrimental.

Genome Announcement: The Draft Genomes of Two populations from Costa Rica.

is an economically important pest of both banana and citrus in tropical regions. Here we present draft genomes from two populations of from Costa Rica that were created and assembled using short read libraries from Illumina HiSeq technology.

Complex Transmission Patterns and Age-Related Dynamics of a Selfish mtDNA Deletion.

Despite wide-ranging implications of selfish mitochondrial DNA (mtDNA) elements for human disease and topics in evolutionary biology (e.g., speciation), the forces controlling their formation, age-related accumulation, and offspring transmission remain largely unknown.

Variable Abundance and Distribution of and Endosymbionts in Plant-Parasitic Nematode Field Populations.

The bacterial endosymbiont interacts with different invertebrate hosts, engaging in diverse symbiotic relationships. is often a reproductive parasite in arthropods, but an obligate mutualist in filarial nematodes. was recently discovered in plant-parasitic nematodes, and, is thus far known in just two genera and , yet the symbiont's function remains unknown.

Sex and Mitonuclear Adaptation in Experimental Populations.

To reveal phenotypic and functional genomic patterns of mitonuclear adaptation, a laboratory adaptation study with nematodes was conducted in which independently evolving lines were initiated from a low-fitness mitochondrial electron transport chain (ETC) mutant, Following 60 generations of evolution in large population sizes with competition for food resources, two distinct classes of lines representing different degrees of adaptive response emerged: a low-fitness class that exhibited minimal or no improvement compared to the mutant ancestor, and a high-fitness class containing lines that exhibited partial recovery of wild-type fitness. Many lines that achieved higher reproductive and competitive fitness levels were also noted to evolve high frequencies of males during the experiment, consistent with adaptation in these lines having been facilitated by outcrossing. Whole-genome sequencing and analysis revealed an enrichment of mutations in loci that occur in a -centric region of the interactome and could be classified into a small number of functional genomic categories.

Comparative Genomics of - Dual Endosymbiosis in a Plant-Parasitic Nematode.

and are among the most important and widespread of all endosymbionts, occurring in nematodes and more than half of insect and arachnid species, sometimes as coinfections. These symbionts are of significant interest as potential biocontrol agents due to their abilities to cause major effects on host biology and reproduction through cytoplasmic incompatibility, sex ratio distortion, or obligate mutualism. The ecological and metabolic effects of coinfections are not well understood.

Comparative Genomic Analysis of 130 Bacteriophages Infecting Bacteria in the Genus .

Bacteria of the genus are genetically diverse and ubiquitous in the environment. Like other bacteria, those of the genus are susceptible to bacteriophages which can significantly affect their host in many ways, ranging from cell lysis to major changes in morphology and virulence. Insights into phage genomes, evolution, and functional relationships with their hosts have the potential to contribute to a broader understanding of biology, and the development of novel phage therapy strategies.

Molecular signatures of host specificity linked to habitat specialization in sea anemones.

Rising ocean temperatures associated with global climate change induce breakdown of the symbiosis between coelenterates and photosynthetic microalgae of the genus . Association with more thermotolerant partners could contribute to resilience, but the genetic mechanisms controlling specificity of hosts for particular types are poorly known. Here, we characterize wild populations of a sea anemone laboratory model system for anthozoan symbiosis, from contrasting environments in Caribbean Panama.

Natural Variation in Responses to Acute Heat and Cold Stress in a Sea Anemone Model System for Coral Bleaching.

Rising ocean temperatures disrupt the symbiosis between corals and their microalgae, accelerating global decline of coral reef ecosystems. Because of the difficulty of performing laboratory experiments with corals, the sea anemone Aiptasia has emerged as an important model system for molecular studies of coral bleaching and symbiosis. Here, we investigate natural variation in bleaching responses among different genetic lineages of Aiptasia.

Adaptive Evolution under Extreme Genetic Drift in Oxidatively Stressed Caenorhabditis elegans.

A mutation-accumulation (MA) experiment with Caenorhabditis elegans nematodes was conducted in which replicate, independently evolving lines were initiated from a low-fitness mitochondrial electron transport chain mutant, gas-1. The original intent of the study was to assess the effect of electron transport chain dysfunction involving elevated reactive oxygen species production on patterns of spontaneous germline mutation. In contrast to results of standard MA experiments, gas-1 MA lines evolved slightly higher mean fitness alongside reduced among-line genetic variance compared with their ancestor.

Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles.

Background: Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) needles at diurnal and circannual scales.

The Draft Genome of .

is a newly described potato cyst nematode (PCN) found in Idaho, Oregon, and Argentina. Here, we present a genome assembly for , a relative of the quarantine nematodes and , produced using data from Illumina and Pacific Biosciences DNA sequencing technologies.

Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts.

Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes.

Paternal Mitochondrial Transmission in Intra-Species Caenorhabditis briggsae Hybrids.

To study mitochondrial-nuclear genetic interactions in the nematode Caenorhabditis briggsae, our three laboratories independently created 38 intra-species cytoplasmic-nuclear hybrid (cybrid) lines. Although the cross design combines maternal mitotypes with paternal nuclear genotypes, eight lines (21%) unexpectedly contained paternal mitotypes. All eight share in common ancestry of one of two genetically related strains.

The mitochondrial genome of Globodera ellingtonae is composed of two circles with segregated gene content and differential copy numbers.

Background: The evolution of animal mitochondrial (mt) genomes has resulted in a highly conserved structure: a single compact circular chromosome approximately 14 to 20 kb long. Within the last two decades exceptions to this conserved structure, such as the division of the genome into multiple chromosomes, have been reported in a diverse set of metazoans. We report on the two circle multipartite mt genome of a newly described cyst nematode, Globodera ellingtonae.

Paths of Heritable Mitochondrial DNA Mutation and Heteroplasmy in Reference and gas-1 Strains of Caenorhabditis elegans.

Heteroplasmy-the presence of more than one mitochondrial DNA (mtDNA) sequence type in a cell, tissue, or individual-impacts human mitochondrial disease and numerous aging-related syndromes. Understanding the trans-generational dynamics of mtDNA is critical to understanding the underlying mechanisms of mitochondrial disease and evolution. We investigated mtDNA mutation and heteroplasmy using a set of wild-type (N2 strain) and mitochondrial electron transport chain (ETC) mutant (gas-1) mutant Caenorhabditis elegans mutation-accumulation (MA) lines.

Genome-wide polymorphism and signatures of selection in the symbiotic sea anemone Aiptasia.

Background: Coral reef ecosystems are declining in response to global climate change and anthropogenic impacts. Yet patterns of standing genetic variation within cnidarian species, a major determinant of adaptive potential, are virtually unknown at genome-scale resolution. We explore patterns of genome-wide polymorphism and identify candidate loci under selection in the sea anemone Aiptasia, an important laboratory model system for studying the symbiosis between corals and dinoflagellate algae of the genus Symbiodinium.

The genomic basis of parasitism in the Strongyloides clade of nematodes.

Soil-transmitted nematodes, including the Strongyloides genus, cause one of the most prevalent neglected tropical diseases. Here we compare the genomes of four Strongyloides species, including the human pathogen Strongyloides stercoralis, and their close relatives that are facultatively parasitic (Parastrongyloides trichosuri) and free-living (Rhabditophanes sp. KR3021).