Comparative genomics of the miniature wasp and pest control agent Trichogramma pretiosum.

TitleComparative genomics of the miniature wasp and pest control agent Trichogramma pretiosum.
Publication TypeJournal Article
Year of Publication2018
AuthorsLindsey, ARI, Kelkar, YD, Wu, X, Sun, D, Martinson, EO, Yan, Z, Rugman-Jones, PF, Hughes, DST, Murali, SC, Qu, J, Dugan, S, Lee, SL, Chao, H, Dinh, H, Han, Y, Doddapaneni, HVardhan, Worley, KC, Muzny, DM, Ye, G, Gibbs, RA, Richards, S, Yi, SV, Stouthamer, R, Werren, JH
JournalBMC Biol
Date Published2018 May 18

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.

Alternate JournalBMC Biol.
PubMed ID29776407
PubMed Central IDPMC5960102
Grant ListMCB 1615664 / / National Science Foundation /
194617 / / National Institute of Food and Agriculture /
DEB 1257053 / / National Science Foundation /
DEB 1501227 / / National Science Foundation /
U54 HG003273 / / National Human Genome Research Institute /
U54 HG003273 / HG / NHGRI NIH HHS / United States
2016-67011-24778 / / National Institute of Food and Agriculture /
IOS 1456233 / / National Science Foundation /