Cassandra Extavour
Department of Organismic and Evolutionary Biology
BioLabs 4103
16 Divinity Ave
Cambridge, MA 02138
Tel: 617-496-1935
Fax: 617-496-9507
Email: extavour@oeb.harvard.edu
Lab Members: 2 postdoctoral fellows, 6 graduate students, 3 undergraduate students
Visit my lab page here.
My lab is interested in the evolution of early embryonic development. We are a collection of developmental biologists, molecular biologists, geneticists, cell biologists, zoologists, and evolutionary biologists. Our shared interest is in the evolution of the genetic mechanisms employed during early animal embryogenesis to specify cell fate, development and differentiation.
We focus primarily on the evolution and development of reproductive systems, including both the germ line and the somatic components of the gonad. We use molecular genetic developmental analysis, histological analysis, and experimental embryology to study early animal embryogenesis, germ cell specification, and gonad development in several different invertebrate model systems. Our laboratory models are Drosophila (fruit fly), Gryllus (cricket), Oncopeltus (milkweed bug), Parhyale (crustacean), and Achaearanea (spider). Our ultimate goal is to improve our understanding of which developmental mechanisms may have been basal to arthropods, and ultimately to metazoans, and how these mechanisms may have changed throughout evolution.
Germ cells play a unique role in gamete production, heredity and evolution. Germ cells are likely also the closest wild type in vivo equivalent to laboratory-maintained stem cells. Therefore, to understand the mechanisms that specify germ cells is a central challenge in developmental, stem cell, and evolutionary biology.
References:
Zeng, V. and Extavour, C.G. ASGARD: an open-access database of annotated transcriptomes for emerging model arthropod species. Database doi: 10.1093/database/bas048 (2012)
Ewen-Campen, B., Srouji, J.R., Schwager, E.E. and Extavour, C.G. oskar predates the evolution of germ plasm in insects. Current Biology 22(23): 2278-2283 (2012) *Read more in the Harvard Gazette*
Green II, D.A., and Extavour, C.G. Convergent Evolution of a Reproductive Trait Through Distinct Developmental Mechanisms in Drosophila. Developmental Biology 372(1): 120-130 (2012)
Sharma, P.P., Schwager, E.E., Extavour, C. G. and Giribet, G. Evolution of the chelicera: a dachshund domain is retained in the deutocerebral appendage of Opiliones (Arthropoda, Chelicerata). Evolution and Development 14(6): 522-533 (2012)
Sharma, P.P., Schwager, E.E., Extavour, C. G. and Giribet, G. Hox gene expression in the harvestman Phalangium opilio reveals divergent patterning of the chelicerate opisthosoma. Evolution and Development 14(5): 450-463 (2012)
Sarikaya, D.P., Belay, A.A., Ahuja, A., Green, D.A., Dorta, A. and Extavour, C.G.The roles of cell size and cell number in determining ovariole number in Drosophila. Developmental Biology Epub Dec 19 (2011)
Zeng, V., Villanueva, K.E., Ewen-Campen, B., Alwes, F., Browne, W.E. and Extavour, C.G. De novo assembly and characterization of a maternal and developmental transcriptome for the emerging model crustacean Parhyale hawaiensis. BMC Genomics 12(1): 581 (2011)
Kainz, F., Ewen-Campen, B., Akam, M. and Extavour, C.G. Delta/Notch signalling is not required for segment generation in the basally branching insect Gryllus bimaculatus. Development 138(22): 5015-5026 (2011)
Alwes, F., Hinchen, B. and Extavour, C G. Patterns of cell lineage, movement, and migration from germ layer specification to gastrulation in the amphipod crustacean Parhyale hawaiensis. Developmental Biology 139(1): 110-123 (2011)
Extavour, C G. Long-Lost Relative Claims Orphan Gene: oskar in a Wasp. PLoS Genetics 7(4): e1002045 (2011)
Green, D.A., Sarikaya, D.P. and Extavour, C.G. Counting in oogenesis. Cell and Tissue Research 344(2): 207-212 (2011)
Ewen-Campen, B., Shaner, N., Panfilio, K., Suzuki, Y., Roth, S. and Extavour, C.G. The maternal and early embryonic transcriptome of the milkweed bug Oncopeltus fasciatus. BMC Genomics 12(1): 61 (2011)
Ewen-Campen, B., Schwager, E.E., Extavour, C.G. The molecular machinery of germ line specification. Molecular Reproduction and Development 77(1): 3-18 (2010)
Extavour, C.G. Oogenesis: Making the Mos of Meiosis. Current Biology 19(12): R489-R491 (2009)
Abzhanov, A., Extavour, C.G., Groover, A., Hodges, S., Hoekstra, H., Kramer, E M., Monteiro, A. Are We There Yet? Tracking the Development of New Model Systems. Trends in Genetics 24(7): 353-360 (2008)
Voronina, E., Lopez, M., Juliano, C. E., Gustafson, E., Song, J. L., Extavour, C.G., George, S., Oliveri, P., McClay, D., and Wessel, G. Vasa protein expression is restricted to the small micromeres of the sea urchin, but is inducible in other lineages early in development. Developmental Biology 314(2): 276-286 (2008)
For a complete listing of publications click here.
Last Update: 1/4/2013