ABSTRACT
The ability of soil-living oribatid mites to disperse fungal propagules on their bodies was investigated. Classical plating methods were applied to cultivate these fungi and to study their morphology. Molecular markers were used for further determination. The nuclear ribosomal large subunit and the nuclear ribosomal internal transcribed spacer of DNA extracts of the cultured fungi as well as total DNA extracts of the mites themselves, also containing fungal DNA, were amplified and sequenced. Based on phylogenetic analysis, a total of 31 fungal species from major fungal groups were found to be associated with oribatid mites, indicating that mites do not selectively disperse specific species or species groups. The detected taxa were mainly saprobiontic, cosmopolitan (e.g., Alternaria tenuissima), but also parasitic fungi (Beauveria bassiana) for whose dispersal oribatid mites might play an important role. In contrast, no mycorrhizal fungi were detected in association with oribatid mites, indicating that their propagules are dispersed in a different way. In addition, fungi that are known to be a preferred food for oribatid mites such as the Dematiacea were not detected in high numbers. Results of this study point to the potential of oribatid mites to disperse fungal taxa in soil and indicate that co-evolutionary patterns between oribatid mites and their associated fungi might be rare or even missing in most cases, since we only detected ubiquitous taxa attached to the mites.
Subject(s)
Arachnid Vectors/microbiology , Fungi/classification , Mites/microbiology , Soil Microbiology , Animals , Base Sequence , Cloning, Molecular , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Ecosystem , Fungi/genetics , Fungi/isolation & purification , Fungi/ultrastructure , Genes, rRNA/genetics , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNA , Species SpecificitySubject(s)
Breeding , Snails/genetics , Alleles , Animals , Female , Gene Frequency , Genetic Variation , Genotype , Heterozygote , Hydroxybutyrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/genetics , Isoenzymes/genetics , Male , Polymorphism, Genetic , Snails/ultrastructure , Spermatogonia/ultrastructureABSTRACT
Treatment of donor bone marrow in vitro with both anti-thymocyte serum (ATS) and anti-mouse brain serum (RAMBS) inhibits the formation of haemopoietic spleen colonies in irradiated and reconstituted mice. This activity of the antisera may be completely (ATS) or partly (RAMBS) eliminated by absorption with thymocytes. The effect of the antisera is complement-independent. Most likely it depends on the existence and functionality of phagocytes (macrophages) in the recipients.