We report here genome sequences and comparative analyses of three closely related parasitoid wasps: Nasonia vitripennis, N. giraulti, and N. longicornis. Parasitoids are important regulators of arthropod populations, including major agricultural pests and disease vectors, and Nasonia is an emerging genetic model, particularly for evolutionary and developmental genetics. Key findings include the identification of a functional DNA methylation tool kit; hymenopteran-specific genes including diverse venoms; lateral gene transfers among Pox viruses, Wolbachia, and Nasonia; and the rapid evolution of genes involved in nuclear-mitochondrial interactions that are implicated in speciation. Newly developed genome resources advance Nasonia for genetic research, accelerate mapping and cloning of quantitative trait loci, and will ultimately provide tools and knowledge for further increasing the utility of parasitoids as pest insect-control agents.

The interactions between retroviruses and their hosts can be of a beneficial or detrimental nature. Some endogenous retroviruses are involved in development, while others cause disease. The Genome Parsing Suite (GPS) is a software tool to track and trace all Retroid agents in any sequenced genome (M. A. McClure et al., Genomics 85:512-523, 2005). Using the GPS, the retroviral content was assessed in four model teleost fish. Eleven new species of fish retroviruses are identified and characterized. The reverse transcriptase protein sequences were used to reconstruct a fish retrovirus phylogeny, thereby, significantly expanding the epsilonretrovirus family. Most of these novel retroviruses encode additional genes, some of which are homologous to cellular genes that would confer viral advantage. Although the fish divergence is much more ancient, retroviruses began infecting fish genomes approximately 4 million years ago.All genetic entities that encode the reverse transcriptase (RT) enzyme are referred to as retroids (22). The formal retroid classification includes endogenous and exogenous retroviruses, as well as pararetroviruses (large DNA viruses), retrotransposons with long terminal repeats (LTRs), retroposons that lack LTRs, retroplasmids, retrointrons, and retrons (20,21,43,44). This classification is based on the phylogeny of the RT protein sequence, the slowest evolving of the retroid gene components (30). In a global analysis of the retroid content of the genomes of the teleost fish Danio rerio (zebrafish), Oryzias latipes (medaka), Gasterosteus aculeatus (stickleback), and Tetraodon nigroviridis (green spotted pufferfish), we identified several new retroviruses (7). Here, we expand those studies, report the genomic details of 11 new fish retroviral species, and provide a reconstruction of the evolutionary history of sequenced fish retroviruses.In general, retroviruses are classified as alpha-, beta-, gamma-, delta-, and epsilonretroviruses, lentiviruses, and spumaviruses. The current characterization of known exogenous and endogenous fish retroviruses places them in the epsilon family (http: //www.ncbi.nlm.nih.gov/ICTVdb/) or between this group and the gammaretroviruses (36). To date, only three members of the epsilon family have been conclusively identified, i.e., walleye dermal sarcoma virus (WDSV) and the walleye epidermal hyperplasia viruses 1 and 2 (WEHV1 and WEHV2), and tentative members include perch hyperplasia virus and snakehead fish retrovirus (SnRV), (http://www.ncbi.nlm.nih.gov/ICTVdb/). Other fish retroviruses include the Atlantic salmon swim bladder sarcoma virus (SSSV) and zebrafish endogenous retrovirus (ZFERV) from D. rerio; both appear to fall between the gamma and epsilon families (36). Studied in less detail is the ERV_Tet species in T. nigroviridis (15), and the retrovirusstickleback (RV-stickleback), RV-brook trout, RV-freshwater houting, and RV-pufferfish retroviruses only identified by using PCR (17).WDSV is associated with the development of seasonal tumors in walleye and, along w...

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