We’re working on rearing the praying mantis Tenodera sinensis. Photo by Jonchee Kao.

We strive not to be bound by the “model organism” limitation. We must find ways around poor experimental tractability, so that we can improve taxon sampling and have the means to study key clades. Thus, when necessary we develop new methods and resources, or extend existing ones, to apply chemical, molecular and genetic analyses to new study systems from many major branches of the largest group of animals on earth, the Arthropoda. This includes sequencing, assembling and annotating genomes and transcriptomes, optimizing embryonic injection protocols to deliver various gene interference reagents, and generating staging tables to allow standardized comparisons of development across experimental conditions.

Injecting early embryos of the large milkweed bug Oncopeltus fasciatus. Photos by Amaneet Lochab.

References

HUH-tagged Cas9 as a platform for efficient ssODN-mediated knock-in via embryo and adult injection in insects. Yu Shirai, Jonchee A. Kao, Tarun Kumar, Naoki Matsuda, Ryoya Nakagawa, Osamu Nureki, Cassandra G. Extavour, Takaaki Daimon in revision, (2025).
Chromosome-scale genome assembly and annotation of the two-spotted cricket Gryllus bimaculatus (Orthoptera: Gryllidae). Kosuke Kataoka, Ryuto Sanno, Tomasz Gaczorek, Upendra Raj Bhattarai, Yuki Ito, Shintaro Inoue, Kei Yura, Toru Asahi, Guillem Ylla, Taro Mito, Cassandra G. Extavour bioRxiv, doi: https://doi.org/10.1101/2025.10.31.685973 (2025). [PubMed]
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Lineage domains and cytoskeletal cables organize a cellular square grid in a crustacean. Beatrice L. Steinert, Leo Blondel, Chandrashekar Kuyyamudi, Evangelia Stamataki, Anastasios Pavlopoulos, and Cassandra G. Extavour bioRxiv, https://doi.org/10.1101/2025.08.31.673345 (2025).

Related Media: [PubMed]
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There and back again: the dynamic evolution of panarthropod germ cell specification mechanisms. Jonchee A. Kao, Emily L. Rivard, Rishabh R. Kapoor and Cassandra G. Extavour bioRxiv, https://doi.org/10.1101/2025.08.05.668520 (2025).

Related Media: [PubMed]
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Divergence of germ cell-less roles in germ line development across insect species. Jonchee A. Kao, Ben Ewen-Campen and Cassandra G. Extavour Developmental Biology, 525: 93-101 (2025). [PubMed]
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Duplex PCR assay to determine sex and mating status of Ixodes scapularis (Acari: Ixodidae), vector of the Lyme disease pathogen. Isobel Ronai, Julia C. Frederick, Alec T. Thompson, Prisha Sharma, Michael J. Yabsley, Utpal Pal, Cassandra G. Extavour and Travis C. Glenn Journal of Medical Entomology, May 7:tjaf043 (2025). [PubMed]
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Promoting developmental diversity in a changing world. Cassandra G. Extavour, Liam Dolan and Karen E. Sears Development, 151:dev204442 (2024).
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Establishment of CRISPR/Cas9-based knock-in in a hemimetabolous insect: targeted gene tagging in the cricket Gryllus bimaculatus. Matsuoka Y., Nakamura, T., Watanabe, T., Barnett, A.A., Tomonari S., Ylla G., Whittle C.A., Noji, S., Mito T., and Extavour, C.G. Development, 152(1): dev199746 (2024). [PubMed]
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Cricket: The third domesticated insect. Mito T., Ishimaru Y., Watanabe T., Nakamura T., Ylla G., Noji S. and Extavour G.C. Current Topics in Developmental Biology, 147:291-306 (2022). [PubMed]
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Genomics and genome editing techniques of crickets, an emerging model for insect biology and food science. Nakamura, T., Ylla, G., and Extavour, C.G. Current Opinion in Insect Science, 2:100881 (2022). [PubMed]
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Insights into the genomic evolution of insects from cricket genomes. Ylla G., Nakamura T., Itoh T., Kajitani R., Atsuhi T., Sayuri T., Tetsuya B., Yoshiyasu I., Watanabe T., Fuketa M., Matsuoka Y., Barnett, A., Noji S., Mito T. and Extavour C.G. Communications Biology, 4(1):733 (2021). [PubMed]
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Chapter 8: The Cricket Gryllus bimaculatus: Techniques for Quantitative and Functional Genetic Analyses of Cricket Biology. Kulkarni, A.* and Extavour, C.G.* Results and Problems in Cell Differentiation, Volume 68: Evo-Devo: Non-model Species in Cell and Developmental Biology (edited by Waclaw Tworzydlo and Szczepan M. Bilinski), 68:183-216 (2019).

Related Media: [PubMed]
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Injecting Gryllus bimaculatus Eggs. Barry, S, Nakamura, T., Matsuoka, Y., Straub, C., Horch, H.W.* and Extavour, C.G. Journal of Visualized Experiments, Aug 22 (150):10.3791/59726 (2019). [PubMed]
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Molecular evolutionary trends and feeding ecology diversification in the Hemiptera, anchored by the milkweed bug genome. Panfilio, K.A.*, Vargas Jentzsch, I.M., Benoit, J.B., Erezyilmaz, D., Suzuki, Y., Colella, S., Robertson, H.M., Poelchau, M.F., Waterhouse, R.M. Ioannidis, P. Weirauch, M.T., Hughes, D.S.T., Murali, S.C., Werren, J.H., Jacobs, G.C.G., Duncan, E.J., Armisén, D., Vreede, B.M.I., Baa-Puyoulet, P., Berger, C.S., Chang, C.-C., Chao, H., Chen, M.-J.M. , Chen, Y.-T., Childers, C.P., Chipman, A.D., Cridge, A.G., Crumire, A.J.J., Dearden, P.K., Didion, E.M., Dinh, H., Doddapaneni, H., Dolan, A., Dugan, S., Extavour, C.G., Febvay, G., Friedrich, M., Ginzburg, N., Han, Y., Heger, P., Horn, T., Hsiao, Y.-M., Jennings, E.C., Johnston, J.S., Jones, T.E. M., Jones, J.W., Khila, A., Koelzer, S., Kovacova, V., Leask, M., Lee, S.L., Lee, C.-Y.,Lovegrove, M.R., Lu, H.-L. Lu, Y. Moore, P.J., Munoz-Torres, M.C., Muzny, D.M., Palli, S.R., Parisot, N. Pick, L., Porter, M., Qu, J., Refki, P.N., Richter, R.,Rivera Pomar, R., Rosendale, A.J., Roth, S., Sachs, L., Santos, M.E., Seibert, J., Sghaier, E., Shukla, J.N.,Stancliffe, R.J., Tidswell, O., Traverso, L., van der Zee, M., Viala, S., Worley, K.C., Zdobnov, E.M., Gibbs, R.A., Richards, S.* Genome Biology, 20(1):64 (2019). [PubMed]
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High-throughput live-imaging of embryos in microwell arrays using a modular specimen mounting system. Donoughe, S.D., Kim, C. and Extavour, C.G. Biology Open, 7(7):bio.031260 (2018). [PubMed]
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