Postdoc María Angélica Bravo Núñez of the Murray Lab was recently named as a 2021 Hanna H. Gray Fellow, a high-profile award from HHMI that funds exceptionally promising early career scientists from diverse backgrounds.
The Hanna H. Gray Fellows Program provides each fellow with a $70,000 annual salary and $20,000 expense allowance for two to four years of postdoctoral work, followed by four years of funding for the fellows’ research when they launch their own labs.
Bravo Núñez and postdoc Zuri Sullivan of the Dulac Lab, who was also chosen as a Hanna H. Gray Fellow, join a network of accomplished early-career scientists. “I feel super-honored…because there’s a very-talented group of people in that Hanna H. Gray group,” says Bravo Núñez. “So it was very humbling, and I’m excited to be part of that now.”
Her decision to pursue a career in biology was strongly influenced by her high school biology teacher. Growing up in Mexico City, Bravo Núñez initially planned to focus on math. However, her teacher pointed out that Bravo Núñez was doing well in biology and chemistry, as well as math, and that studying biology would allow her to combine those interests.
Bravo Núñez attended the National Autonomous University of Mexico (UNAM) for her undergraduate education. A research experience at Baylor College of Medicine in Texas during her senior year convinced her to pursue biology research as a career.
Her graduate work at the Stowers Institute for Medical Research in Kansas City, Missouri focused on selfish genes that “cheat” at meiosis by poisoning gametes containing competing alleles. Only gametes carrying the selfish gene’s allele can produce an antidote to the poison and survive. Genes like these are called meiotic drivers.
In a recent study, Bravo Núñez crossbred two strains of yeast that carried different versions of the meiotic driver’s poison and antidote. Most of the hybrid gametes died. However, the few gametes that escaped the poisoning often had an extra chromosome. “What that allows the new cell to do is to produce all of the antidotes,” Bravo Núñez says. “Despite the cell being aneuploid, [because] it has an extra chromosome, it survives!”
“Aneuploidy is usually thought of as being detrimental to organisms,” she adds. “Work from other scientists and the work I did in grad school show that might not always be the case and that specific types of aneuploidy may really be advantageous.”
Bravo Núñez decided to continue investigating situations where aneuploidy can be beneficial for a cell. Right now, she is conducting experiments with yeast, but the implications of her research could reach much farther.
“Cancer cells are almost strictly aneuploid,” she explains. “It is not really known how these aneuploidies are being produced and then maintained. One of the ideas I have is that maybe some of the genes that are normally expressed during meiosis—when gametes are produced—could potentially be driving these aneuploidies in cancer cells.”
However, this research on meiotic genes’ role in aneuploid cells is only one of her postdoctoral projects. “Her second project is to try and understand a mysterious process called parameiosis that some fungi use to roughly halve their chromosome number, without going through meiosis,” says MCB faculty and Bravo Núñez’s advisor Andrew Murray. “She’s started a hunt for mutations that produce parameiosis, or something like it, in brewer’s yeast, and she’s also going to investigate the process in Candida albicans, a fungus that uses parameiosis and often infects—and sometimes kills—immunocompromised patients. I’m excited about both projects, both because they’ll tell us about fundamental mechanisms that cause unusual patterns of chromosome inheritance and because they each have potential implications to human disease.”
He adds, “Maria is awesome! She’s a fantastic experimentalist, bright and creative, a science junkie, incredibly dedicated, engaged in and supportive of her colleagues’ work, and committed to mentorship that will increase the diversity of the scientific community. I’m delighted and lucky that she chose to join my lab.”
Bravo Núñez is also involved in outreach and mentoring efforts, such as Científico Latino , which helps Latinx students learn the ropes of applying to grad school and other aspects of scientific careers. “I was blessed with having really good mentors and a teacher that was like, “You should do biology. Go be a scientist!’” she says. “I think you should pay that forward. So I hope I can encourage and inspire hopefully soon-to-be scientists, just like the mentors I have inspiring and encouraging me.”
by Diana Crow
