Comparative genomics of the miniature wasp and pest control agent Trichogramma pretiosum
Amelia R. I. Lindsey,
Yogeshwar D. Kelkar,
Xin Wu,
Dan Sun,
Ellen O. Martinson,
Zhichao Yan,
Paul F. Rugman-Jones,
Daniel S. T. Hughes,
Shwetha C. Murali,
Jiaxin Qu,
Shannon Dugan,
Sandra L. Lee,
Hsu Chao,
Huyen Dinh,
Yi Han,
Harsha Vardhan Doddapaneni,
Kim C. Worley,
Donna M. Muzny,
Gongyin Ye,
Richard A. Gibbs,
Stephen Richards,
Soojin V. Yi,
Richard Stouthamer,
John H. Werren
Affiliations
Amelia R. I. Lindsey
Department of Entomology, University of California Riverside
Yogeshwar D. Kelkar
Department of Biology, University of Rochester
Xin Wu
School of Biological Sciences, Institute for Bioengineering and Bioscience, Georgia Institute of Technology
Dan Sun
School of Biological Sciences, Institute for Bioengineering and Bioscience, Georgia Institute of Technology
Ellen O. Martinson
Department of Biology, University of Rochester
Zhichao Yan
Department of Biology, University of Rochester
Paul F. Rugman-Jones
Department of Entomology, University of California Riverside
Daniel S. T. Hughes
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Shwetha C. Murali
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Jiaxin Qu
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Shannon Dugan
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Sandra L. Lee
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Hsu Chao
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Huyen Dinh
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Yi Han
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Harsha Vardhan Doddapaneni
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Kim C. Worley
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Donna M. Muzny
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Gongyin Ye
State Key Laboratory of Rice Biology & Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University
Richard A. Gibbs
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Stephen Richards
Human Genome Sequencing Center, Department of Molecular and Human Genetics, Baylor College of Medicine
Soojin V. Yi
School of Biological Sciences, Institute for Bioengineering and Bioscience, Georgia Institute of Technology
Richard Stouthamer
Department of Entomology, University of California Riverside
Abstract Background Trichogrammatids are minute parasitoid wasps that develop within other insect eggs. They are less than half a millimeter long, smaller than some protozoans. The Trichogrammatidae are one of the earliest branching families of Chalcidoidea: a diverse superfamily of approximately half a million species of parasitoid wasps, proposed to have evolved from a miniaturized ancestor. Trichogramma are frequently used in agriculture, released as biological control agents against major moth and butterfly pests. Additionally, Trichogramma are well known for their symbiotic bacteria that induce asexual reproduction in infected females. Knowledge of the genome sequence of Trichogramma is a major step towards further understanding its biology and potential applications in pest control. Results We report the 195-Mb genome sequence of Trichogramma pretiosum and uncover signatures of miniaturization and adaptation in Trichogramma and related parasitoids. Comparative analyses reveal relatively rapid evolution of proteins involved in ribosome biogenesis and function, transcriptional regulation, and ploidy regulation. Chalcids also show loss or especially rapid evolution of 285 gene clusters conserved in other Hymenoptera, including many that are involved in signal transduction and embryonic development. Comparisons between sexual and asexual lineages of Trichogramma pretiosum reveal that there is no strong evidence for genome degradation (e.g., gene loss) in the asexual lineage, although it does contain a lower repeat content than the sexual lineage. Trichogramma shows particularly rapid genome evolution compared to other hymenopterans. We speculate these changes reflect adaptations to miniaturization, and to life as a specialized egg parasitoid. Conclusions The genomes of Trichogramma and related parasitoids are a valuable resource for future studies of these diverse and economically important insects, including explorations of parasitoid biology, symbiosis, asexuality, biological control, and the evolution of miniaturization. Understanding the molecular determinants of parasitism can also inform mass rearing of Trichogramma and other parasitoids for biological control.
