Author: Ibon Cancio, UPV/EHU Associated Professor in Cell Biology; researcher in the ‘Cell Biology & Environmental Toxicology’ (CBET) research group of the Plentzia Marine Station (PiE-UPV/EHU); Spanish scientific representative in the EMBRC Committee of Nodes
Ethel Browne was born in Baltimore (USA) on the 14th of December 1885. In 1915, she married a physiologist specialised in bioluminescence research. From that marriage, she obtained, among other things (two sons, for instance), a new surname, to be added to hers, and a shift to a part-time career in science. Ethel Browne Harvey, the great zoologist and unavoidable embryologist, died from appendicitis in 1965. What happened in between?
After getting her bachelor’s degree in 1906, she obtained a masters in zoology from Columbia in 1907. At Columbia, she worked with Edmund Beecher Wilson, the supervisor of her 1913 PhD on the cell biology of spermatocytes in the aquatic heminoptera Noctonecta. Her other mentor in the early Columbia years was Thomas Hunt Morgan, father of molecular genetics and Nobel Prize winner in 1933. During her studies, she received fellowships to promote science careers among women, like the Groucher scholarship (1906-7), that of the Society for the Promotion of University Education for Women (1911-12), and later the ‘Sarah Berliner Research’ scholarship (1914-15) that she used for a research stay at the Hopkins Marine Station of California.
As a student in her very early twenties at Columbia, and from 1906 to 1908, Browne made a discovery that possibly shaped the discipline of developmental biology, at least conceptually. Browne demonstrated that transplanting the hypostome from one hydra into another one would induce a secondary axis in the host hydra. This work, published in 1909 was performed following the advice of Morgan, as she explained in the introductory paragraph of her paper. This could be truly considered the (allegedly) most important paper in the history of developmental biology; however, another publication that didn’t appear until 1924 (and essentially mirrors Browne’s 1909 paper) is ‘de facto’ considered the founding one in the history of developmental biology. We are talking about the paper on the ‘organiser’ of Hilde Mangold and Hans Spemann. Browne’s first study had the aquatic organism Hydra viridissima as a model organism; the ‘second comer’, that resulted in the Nobel Prize for Spemann in 1935, addressed early embryo development in two species of amphibians: Triturus cristatus and taenatius.
In her experiments, Browne demonstrated that transplanting a part of the developing hydra embryo without yet establishing antero-posterior axis polarity (no distinction between front and rear) induced the creation of a secondary axis of polarity in the transplanted host, with a new body growing protruding from the grafted area. Okay, you are not a scientist (sorry, a biologist), and you do not understand what this ‘antero-posterior axis of polarity’ means. Picture an oocyte in your brain. As a student, you probably used to draw it as a perfect circumference, so there is no polarity, no front or rear, no up or down. Then how do you design polarity in a fertilised egg? You need a set of cells in the embryo molecularly inducing (primary embryo induction) processes that will result in development of front-side structures and organs in one site (head and mouth for instance) and rear-side specific structures (tail, legs of anus for instance) in the other.
Browne transplanted the mouth tissue (hypostome) of the diploblastic hydra while Mangold and Spemann transplanted the lip of the blastopore of the amphibian embryo. Browne described how this mouth tissue of the hydra, when grafted at a certain site in the body wall of another one, resulted in the development of a new Siamese hydranth attached in the grafted site. The key question here was whether the transplanted tissue induced the formation of a new Siamese individual from the host tissue, or whether the grafted cells, when transplanted, were induced to form a new hydranth. Induce or be induced! Browne devised an experiment to solve this question that involved using green pigmented (containing symbiotic intracellular algae) and non-pigmented hydras. When grafting the hypostome of a non-pigmented individual into the body of a pigmented one, she showed that the pigmented host tissue was induced to develop into a hydranth. The small piece of grafted tissue ‘organised’ the neighbouring host tissue, ‘inducing’ it to develop a second embryo. Through the graft, the host received a second hypostome, and both hypostomes induced their adjacent tissue to develop their own polarity axis. She perfectly understood the meaning and the relevance of her discovery. Remember, Ethel was only 23 years old and she still was only Ethel Browne.
Okay, hydra is a non-marine aquatic organism, but Browne was a marine biologist who was member of the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts, where she worked for more than 50 years starting in 1909. From 1950 to 1958, she served on the MBL board, only the second woman ever elected to the position. Very possibly, there she met many times the mentor of her early University years, Thomas Hunt Morgan, before and after he obtained his Nobel Prize, and also a MBL habitual.
MBL was a place where you went in summertime to conduct your research by the sea. For Browne, her summertime research would focus on the early development of sea urchins and, more specifically, in parthenoegenesis. This provided no salary. For that, you had to work the rest of the year. She was a math and science teacher at the Bennett School for Girls in Millbrook (NY) between 1908-1911, a biology lab assistant at Princeton University (1912-13), a biology instructor at Wellesley's Dana Hall (1913-14), biology laboratory assistant at Cornell Medical College in New York (1915-16) and biology instructor at Washington Square College (1928-31). The bulk of her career took place at the department of biology at Princeton University (1931-62), where her husband, Edmund Newton Harvey, was a professor.
From1925-1926, Browne Harvey worked at Stazione Zoologica Anton Dohrn (SZN) in Naples with a scholarship from the Naples Table Association for Promoting Scientific Research by Women. It is curious to know that Spemann worked at SZN four times, the last two times in 1926 and 1927. In 1933, 1934 and 1937, Browne-Harvey worked again at SZN, occupying on each occasion the Jacques Loeb Memorial Table of the Rockefeller Institute of New York. We find Spemann here once again as he obtained his Nobel Prize in 1935. In the 1930s, Browne Harvey demonstrated a centrifugation method for the extraction of the nucleus from the sea urchin eggs, which upon induction of fertilisation without sperm (parthenogenesis=virgin birth) could be seen to cleave (divide) and ultimately to hatch. Her experiments showed that cytoplasm was capable of directing cleavage without the need for the nucleus. She termed this way of immaculate conception from enucleated eggs ‘parthenogenic merogony’, and of course it does not give rise to a viable organism. She performed such experiments first at MBL with American sea urchins, and during her trips to Naples, she replicated them in European species.
Browne Harvey’s dedication to sea urchins during her years working at MBL and SZN was capitalised in a definitive reference text on her favourite laboratory pet, Arbacia punctulata, published in 1956 (The American Arbacia and Other Sea Urchins). Now take all that knowledge and think about Tim Hunt arriving at MBL in the 1980s to work on Arbaciaeggs and discovering cyclins there. That is the Nobel Prize in medicine in 2001. Now think of the work of Browne Harvey at SZN with Arbacia pustulosa (now Arbacia lixula). Otto Warburg described the oxidative burst upon fertilisation in the eggs of Arbacia pustulosa during his first stay at SZN in 1908. From those findings, he initiated work on oxidative metabolism finding cytochrome-C-oxidase and obtaining his Nobel Prize in 1931. Yes, in-between the visits of Browne Harvey to Naples. Some people see raindrops falling from the sky, others see Nobel Prizes falling around them!