Anne McLaren dies

Dame Anne McLaren, a geneticist and reproductive biologist at the University of Cambridge, UK, who was one of the first to culture mouse embryos outside the womb, was killed in a car crash outside London on July 7. She was 80 years old.

McLaren helped craft the UK's Human Fertilisation and Embryology Act of 1990, and was the first female officer of the Royal Society.

"At 80, she was still very much a force in the field - intellectually and spiritually," David C. Page, director of the Whitehead Institute for Biomedical Research, told The Scientist. In the areas of reproductive biology and mammalian developmental biology, he said, "she was an entirely positive influence on the field." At the end of her career, McLaren focused on primordial germ cells, working to understand what determines cell differentiation.

McLaren was the daughter of Henry McLaren, second Lord Aberconway. She studied zoology as an undergraduate and went on to do graduate work at University College London, where she researched mite infestation of Drosophila under the prominent geneticist J.B.S. Haldane.

Soon after, she turned her attention from fly genetics to mouse embryonic development - an area where she was to make a great impact, said Janet Rossant, an embryologist at the Hospital for Sick Children in Toronto. While earning her PhD at Oxford University, Rossant was influenced and inspired by McLaren's work, and she frequently turned to her for advice. "She was one of the founders of the field of mammalian development," Rossant told The Scientist.

In 1958, McLaren worked with John Biggers at University College London to grow early mouse embryos for 24 hours outside the womb, then transfer them back to the mother's body for an eventual successful birth. "She was one of the first people to show that you could culture mouse embryos outside the womb," said Duke University biologist Brigid Hogan, who came to know McLaren while working on her PhD at Cambridge. "That was very important for the development of in vitro fertilization."

McLaren was also among the first researchers "to recognize the maternal influence of the uterine environment on the development of the mouse embryo," Hogan said.

Later in her career, McLaren focused on the development of mouse primordial germ cells, the embryonic cells that give rise to eggs and sperm. During the 1980s, Page noted, many researchers set their sights on investigating mammalian sex determination, looking for the pertinent gene or genes on the Y chromosome. McLaren was among the first to point out that understanding primordial germ cells was also a key component of this research.

"She recognized the importance of such things far before the rest of the field could come to grips with it," Page said. "She was a prophetess in the field."

McLaren's most highly-cited paper, published in Development in 1990 and cited 334 times, identified primordial germ cells in the embryonic mesoderm of 7-day-old mouse embryos, setting the stage for further study of how differentiation of the germ cell lineage is controlled. A later study identified a mechanism controlling the entry of germ cells into meiosis. That paper, published in Developmental Biology in 1997, was cited 110 times.

McLaren was also actively involved in social and ethical discussions of human embryology research. As a member of the Warnock Committee, she helped craft the UK's Human Fertilisation and Embryology Act of 1990. She argued that when well informed of the risks and benefits of scientific technologies, the public could be trusted to make sound decisions about stem cell and other scientific research. "Her role was in making sure the science was clearly understood," Rossant said.

In 1975 McLaren was made a fellow of the Royal Society, and she was awarded one of the Society's Royal Medals in 1990. The following year she became the first female officer of the Society, serving as its foreign secretary until 1996. In that role, said Hogan, she traveled widely and made a point to reach out to scientists in underprivileged countries such as Cuba.

McLaren was also widely known as a mentor who spent a great deal of time discussing science with her students and colleagues. "Her broad expertise and her wisdom have made her much more than an important scientist," said Rossant. "She was also an important mentor and role model."

McLaren's ex-husband Donald Michie, 84, a researcher in artificial intelligence, was also killed in the crash. They are survived by three children, as well as Michie's one child from a previous marriage.

Kirsten Weir
mail@the-scientist.com

Photo credit: University of Cambridge

Links within this article:

Human Fertilisation and Embryology Act
http://www.opsi.gov.uk/acts/acts1990/Ukpga_19900037_en_1.htm

David C. Page
http://www.wi.mit.edu/research/faculty/page.html

Janet Rossant Laboratory
http://www.sickkids.ca/rossant/default.asp

A. McLaren and J.D. Biggers, "Successful development and birth of mice cultivated in vitro as early as early embryos," Nature, September 27, 1958
http://www.the-scientist.com/pubmed/13590153

Brigid Hogan
http://www.cellbio.duke.edu/Faculty/Research/Hogan.html

L.M. Hrastar, "Male cells can grow eggs, too," The Scientist, March 1, 2005
http://www.the-scientist.com/article/display/22611

M. Monk and A. McLaren, "X-Chromosome activity in foetal germ cells of the mouse," Journal of Embryology and Experimental Morphology, June, 1981
http://www.the-scientist.com/pubmed/7310296

M. Ginsburg et al, "Primordial germ cells in the mouse embryo during gastrulation," Development, October, 1990
http://www.the-scientist.com/pubmed/2133553

A. McLaren and D. Southee, "Entry of mouse embryonic germ cells into meiosis," Developmental Biology, July 1, 1997
http://www.the-scientist.com/pubmed/9224678

A. McCook, "Stem cells: Ethics before science," The Scientist, March 28, 2006
http://www.the-scientist.com/blog/display/23251

Readers and editors of The Scientist, "Cracking cloning," The Scientist, June 1, 2007
http://www.the-scientist.com/blog/display/23251

Dr Anne McLaren FRS- Of mice and maternity
http://www.royalsoc.ac.uk/page.asp?id=1536

Donald Michie
http://www.aiai.ed.ac.uk/_dm/dm.html