Final Activity Report Summary - MITYMODEL (Genomics and genetics of spider mite Tetranychus urticae: development of novel model organism important for agriculture) Genetic model systems, such as c. elegans, fruitfly, zebrafish and mouse have rapidly advanced our understanding of genetics, development, population biology and evolution. These species became model organisms partly because of several common characteristics, such as rapid development, relatively small genomes and easy laboratory maintenance. Up to date, the development of a chelicerate model system was hampered by their complex ontogeny, long development time and large genomes. Thus, a challenge for the future progress for many aspects of chelicerate biology is the development of a model organism for this group. Towards this end, we are developing a chelicerate genetic model, consisting the two spotted spider mite tetranychus urticae. As representatives of this basal taxon of arthropods, spider mites are of special importance to several areas of science including phylogenetics, developmental biology, evolution, ecology and genomics. In addition, spider mites are major agricultural pests, being therefore of substantial economic importance and significance for the biotechnology of pest control and energy conservation. T. urticae has one of the smallest genomes in arthropods that are determined so far (75 Mbp, representing 60 % of the size of the drosophila genome), undergoes rapid development and is easy to maintain in the lab. These features make t. urticae an excellent candidate for developing into a chelicerate model system. The main goal of this project was to establish genetic and genomic resources in this species which would facilitate future fundamental and applied studies. During the tenure of Marie Curie fellowship, in collaboration with Joint Genome Institute (JGI), we constructed spider mite fosmid and plasmid genomic libraries and cDNA libraries from embryos, larvae and adults from t. urticae London strain, which served as a reference. In addition, we prepared plasmid librarie from t. urticae polymorphic Montpellier strain. The sequencing of the polymorphic strain would provide us with single nucleotide polymorphism (SNP) markers and indels, which would be used for the construction of the genetic and linkage map of t. urticae. This work resulted in an entire genome sequencing project by the United States Department of Energy JGI, which was underway by the time of this report and which would produce 8X sequence-coverage of the genome of t. urticae London strain and 1X sequence-coverage of the Montpellier strain. This sequencing project would generate one of the first whole genome sequences of a major agricultural pest. Along with developed protocols for antibody and in situ detection of proteins and ribonucleic acid (RNA) distributions and RNAi reverse genetic gene silencing these new tools would open new perspectives and approaches in comparative and functional genomics. Cumulatively, this research would expand our knowledge of pest genomics and would provide tools for the reduction of environmental pollution and energy consumption via biotechnological pest control, resulting in improved human health and sustainable agricultural production.
