Dr. Cassandra Extavour – Biologist and musician

Thanks to the amazing grant of £1000 given to us by the Royal Astronomical Society, we’ve been able to hire writers for our blog posts on scientists of colour. This incredible article was written by the wonderful Marisol Imani Dothard! Marisol can be found on twitter @microbiomarisol and Dr. Extavour can be found on twitter @redmakeda

“Every time I hear a student tell me, ‘I am so glad you are in the department and just knowing that gives me so much strength to go through my studies’, makes it worthwhile.”

Name: Dr. Cassandra Extavour, PhD

Born: Toronto, Canada

Twitter: @redmakeda

Lab website: http://extavourlab.com

Musical website: cassandraextavourmusic.com

Dr. Extavour is a fierce Black queer scientist from Canada who is championing work in the developmental biology field. She currently holds a full Professor position and a successful lab at Harvard University while maintaining a busy career as a professional soprano.

A Musical Early Life with a Twist

Though she would go on to pursue a scientific career full of extraordinary firsts later in life, Cassandra Extavour was raised in a home that mainly nourished her musical and artistic talents throughout her earliest years. Starting her first instrumental lessons at the age of 4, Extavour was an accomplished musician in her community and followed her passion for the arts all the way through high school. Later in high school Extavour realized she had a knack for math and science, which generated a lingering interest in developmental genetics that she would explore in college and for the rest of her academic career. [1]

Scientific Training

To pursue her still-developing love of science, Extavour put herself through school at the University of Toronto and earned a Bachelor of Science in molecular genetics and molecular biology. Extavour next set her sights on applications to PhD programs abroad; she was fascinated by the developmental genetic work of her soon-to-be advisor Dr. Antonio Garcia-Bellido at the Autonomous University of Madrid. However, upon reaching out to him Extavour was told that he did not take international students without their own independent funding. Resilient in the face of this roadblock, Extavour relentlessly applied to fellowships until she found short-term funding to start her journey in Spain. Eventually, Extavour applied for and was awarded a longer-term grant not dissimilar to the National Science Foundation’s Graduate Research Fellowship Program (NSF GRFP) to fund her research on the biology of early embryonic development. [2]

Landmark Early-Career Findings

Dr. Extavour’s thesis work in Spain fundamentally changed our understanding of evolution. Germ cells, or the precursor cells to gametes like sperm and ova, can harbor mutations in much the same way as those found in somatic cells. Only a small portion of germline precursor cells go on to become gametes, so Extavour aimed to determine if the genetic mutations in precursor cells played a significant role in their gametic fate. In short, since gametes are ultimately what determine the genetic identity of the embryo, Extavour’s work interrogated if natural selection is influencing the genetics of future offspring before sexual reproduction even takes place!

Using Drosophila melanogaster, or fruit flies, as a model, Extavour used clones of germline populations with genetic deficiencies and tracked how many cells ultimately went on to become gametes. The resulting findings demonstrated that cell-cell competition does in fact exist between germ cells, which illuminated a crucial step of selection at the pre-zygotic level. [3]

A figure from Extavour’s thesis showing normal fly ovarioles(a) and cells with a blue tracker to count how many recombinant cells went on to become ovarioles(b-d).

A Successful and Ambitious Career

After defending her PhD, Extavour spent her post-doctoral fellowships combining her interests in germline development with a novel pursuit of establishing nontraditional genetic models. Extavour became a pioneer of championing novel models and exploring germ cell development because she felt that the key to understanding human early embryonic development lay outside the short list of traditional genetic models. Extavour began her own independent laboratory in 2007. Her lab’s primary interests were cell signaling in early embryonic development, with a particular and unique interest in developing non-traditional arthropod models. [4] Soon after the creation of her lab, Extavour successfully secured the first Black female tenured professorship at Harvard’s prestigious Faculty of the Arts and Science. [5] Today, Dr. Extavour runs a bustling (and diverse) lab at Harvard that focuses on finding new insect models to examine unique methods of early developmental dynamics. [6] Since 2019, Extavour also works as an editor for the scientific journal Development. This is an especially powerful position as it allows her to handpick scientific publications, thus giving her a powerful role that few Black women occupy. Extavour is a force to be reckoned with, trail-blazing the way for other Black women and queer scientists.

The life cycle of Drosophila, the main model Dr. Extavour works with.

Not just a scientist — Extavour’s Singing Career

Dr. Extavour has received awards at every stage of her academic career for her pioneering efforts in developmental biology, but her dedication to science has never precluded her from pursuing her original passions as a musician. Extavour kept close to her musical roots throughout her graduate career by taking lessons in classical voice. Her vocal coaches encouraged her to seek out professional singing opportunities, and she has since been very successful as a soprano ever since. She has performed both as a soloist and in ensembles in America and abroad. Extavour sang solo roles in Handel’s Messiah and in archetype classical operas like The Marriage of Figaro (W.A.Mozart) and Hansel and Gretel (Humperdinck).She currently sings in the Handel and Hayden Society and Emmanuel Music around Boston and has a separate professional website for her musical career. [7]

Extavour singing with the Handel and Hayden Society in Boston

Authors’s note: On the importance of intersecting identities connecting the arts and science

Many people believe the left-brained world of science leaves no room for a narrative in which its members are capable of artistic or creative endeavors; they see no overlap in the black-and-whiteness of logic and the colorful world of the arts. As an Afro-Latinx PhD student in Microbiology with undergraduate degrees in Biology and Classical Voice, I have always questioned the intellectual labels that seem so clearly to define what and for whom things are possible. Scientists like Dr. Extavour and me —Black women, no less—stand in defiance of these binary labels by thriving at the intersection of science and the arts. More broadly, Dr. Extavour boldly questions the labels that dictate canon, both in the pursuit of nontraditional genetic models and in simultaneously occupying multiple professional spaces predominated by white voices. Our mere existence proves these binary paradigms wrong; our outstanding success shifts those paradigms for those who come after us.


[1]: Interview with Dr. Extavour: https://www.iamascientist.info/cassandra-extavour

[2]: Interview with Dr. Extavour: https://www.ronfanfair.com/home/2018/1/24/professor-blazing-a-trail-for-black-women-in-science

[3]: Dr. Extavour’s thesis work: Extavour, C.; Garcia-Bellido, A. (2001). “Germ cell selection in genetic mosaics in Drosophila melanogaster”. Proceedings of the National Academy of Sciences. Proceedings of the National Academy of Sciences of the United States of America. 98 (20): 11341–11346. doi:10.1073/pnas.201409198

[4] Aiden Marteens. An Interview with Cassandra Extavour. Development 2019. doi: 10.1242/dev.176016 Published 22 February 2019

[5]Interview with Dr. Extavour:  https://www.ronfanfair.com/home/2018/1/24/professor-blazing-a-trail-for-black-women-in-science

[6] Dr. Extavour’s lab website: https://www.extavourlab.com/people/cassandra-g-extavour/

[7] Dr. Extavour’s professional musician website: http://cassandraextavourmusic.com/

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