The polyamine and amino acid composition of the mermithid nematode, Romanomermis culicivorax, and its host, Aedes aegypti, was determined. Putrescine, spermidine, spermine, cadaverine and two acetylated spermidine derivatives were present in parasitic juveniles, newly-emerged post-parasites, and eggs of R. culicivorax. Whole insect homogenates of fourth-instar A. aegypti contained the same arra...

We are studying the evolution of parasitism in a group of soil-living ascomycetes that can grow as saprophytes as well as parasites by forming special morphological structures called traps. Analyses of 18S ribosomal DNA sequences have shown that these fungi form a monophyletic and isolated clade among the ascomycetes. The phylogenetic patterns within this clade are concordant with the morpholog...

The advent of parasite genome sequencing projects, as well as an increase in biology-directed gene discovery, promises to reveal genes encoding many of the key molecules required for nematode-host interactions. However, distinguishing parasitism genes from those merely required for nematode viability remains a substantial challenge. Although this will ultimately require a functional test in the...

The phylogenetic relationships of chemoautotrophic endosymbionts in the gutless marine oligochaete Inanidrilus leukodermatus to chemoautotrophic ecto- and endosymbionts from other host phyla and to free-living bacteria were determined by comparative 16S rRNA sequence analysis. Fluorescent in situ hybridization confirmed that the 16S rRNA sequence obtained from these worms originated from the sy...

Apple replant disease affects tree nurseries and apple production globally. After repeated planting in the same soil, roots show accumulation of phytoalexins, stunting, blackening. Recently, we showed that nematodes extracted from replanted soil co-extracted microbes triggered these symptoms, while pathogens or plant-parasitic could not explain early development. To identify nematode-microbe co...

Nematodes are very common animals and they have repeatedly evolved parasitic lifestyles during their evolutionary history. Recently, the genomes of many nematodes, especially parasitic species, have been determined, potentially giving an insight into the genetic and genomic basis of nematodes' parasitism. But, to achieve this, phylogenetically appropriate comparisons of genomes of free-living a...

Nematophagous fungi are soil-living fungi that are used as biological control agents of plant and animal parasitic nematodes. Their potential could be improved by genetic engineering, but the lack of information about the molecular background of the infection has precluded this development. In this paper we report that a subtilisin-like extracellular serine protease designated PII is an importa...

Root-knot nematodes are obligate parasites of a wide range of plant species and can feed only on the cytoplasm of living plant cells. In the absence of a suitable plant host, infective juveniles of strain VW9 of the Northern root-knot nematode, Meloidogyne hapla, when dispersed in Pluronic F-127 gel, aggregate into tight, spherical clumps containing thousands of worms. Aggregation or clumping b...

to understand the relationship between natural physicochemical properties of soil and abundance of citrus root nematode (tylenchulus semipenetrans), a survey was conducted during 2009-2010 in some 37 citrus orchards, in kohgilouyeh va boyerahmad province, iran. distribution of the citrus nematode was determined by collecting random samples from the soil and citrus plant roots, extracting and en...