BBS Faculty Member - Cassandra Extavour

Cassandra Extavour

Department of Organismic and Evolutionary Biology

Harvard, FAS Org. and Evol. Biology
BioLabs 4103
16 Divinity Ave
Cambridge, MA 02138
Tel: 617-496-1935
Fax: 617-496-9507
Lab Members: 4 postdoctoral fellows, 4 graduate students, 3 undergraduate students
Visit my lab page here.

My lab is interested in the evolution of early embryonic development. Specifically, we want to understand the evolution and function of genes that ensure cell fate specification during embryogenesis, and how these genes may have facilitated the evolution of multicellularity in eukaryotes. We are a collection of developmental biologists, molecular biologists, geneticists, biochemists, 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 not only the traditional model organism Drosophila (fruit fly), but also a number of additional "emerging model organisms" including other insects, crustaceans, spiders, and sometimes even scorpions! Our ultimate goal is to improve our understanding of which developmental mechanisms may have been ancestral in animals, 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.

Last Update: 6/19/2014


For a complete listing of publications click here.



Donoughe, S., Nakamura, T., Ewen-Campen, B., Green II, D.A., Henderson, L. and Extavour, C.G. BMP signaling is required for generation of
primordial germ cells in an insect.
Proceedings of the National Academy of Sciences of the USA 111(11): 4133-4138 (2014)

Ahuja, A. and
Extavour, C.G . Patterns of molecular evolution of the germ line specification gene oskar suggest that a novel domain may contribute to functional divergence in Drosophila. Development, Genes and Evolution 224(2): 65-77 (2014)

Sharma, P.P., Gupta, T., Schwager, E.E., Wheeler, W., and
Extavour C.G. Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata. EvoDevo 5(1): 3 (2014)

Gupta, T. and
Extavour, C.G . Identification of a putative germ plasm in the crustacean Parhyale hawaiensis.EvoDevo 4(1): 34 (2013)

Nast, A. R. and
Extavour, C.G. Ablation of a single cell from eight-cell embryos of the amphipod crustacean Parhyale hawaiensis. Journal of
Visualized Experiments
March 16, Issue 85, doi:10.3791/51073 (2014)

Extavour, C.G. Live long and prosper: Germline stem cell maintenance revisited. BioEssays 35(9): 763 (2013)

Ewen-Campen, B., Donoughe, S., Clarke, D.N., and
Extavour, C.G. Germ Cell Specification Requires Zygotic Mechanisms Rather Than Germ Plasm in a Basally Branching Insect. Current Biology 23(10): 835-842 (2013)

© 2013 by the President and Fellows of Harvard College