01/02.2020 | THE SCIENTIST 47CAREER TITLES/AWARDS
Professor, Department of Molecular and Cell Biology, University
of California, Berkeley
Investigator, Howard Hughes Medical Institute
Elected Member, National Academy of Medicine (2018)
E.B. Wilson Medal, American Society for Cell Biology (2018)
Thomas Hunt Morgan Medal, Genetics Society of America (2018)
Greatest Hits
- Identifi ed a genetic switch that determines whether
bacteriophage lambda becomes virulent or lives dormant
in a host’s genome - Found the “master sex-switch gene” that determined
whether C. elegans becomes male or hermaphrodite and
controlled dosage compensation—the process of balancing
X chromosome expression that is crucial to an organism’s
survival - Discovered that parts of the protein complex involved in
dosage compensation are co-opted from the machinery
used to segregate chromosomes in mitosis and meiosis - Revealed that the size of a nematode’s genome diff ers based
on its mode of reproduction (sexual vs. self-fertilization)
one of these two paths. At the time, scientists had discovered
that the phage itself carried a repressor, a protein that inhibits
gene expression by binding to DNA. They knew this protein
was involved in determining a phage’s fate, but the mechanism
behind its function was an open question. “The fact that there
was a genetic switch that enabled that decision—I really wanted
to understand that,” Meyer says.
Her advisor, Harrison Echols—a biologist who conducted
pioneering work on bacteriophage lambda—thought that trying
to understand the genetic switch was too difficult for her to
pursue, Meyer recalls; as an alternative, he suggested she map out
all the promoter sequences for RNA polymerases in the lambda
phage’s DNA. So, she put her passion project on hold and began
mapping polymerase promoters.
A few months later, she sat in on a seminar by molecular
biologist Mark Ptashne, then a professor at Harvard University.
Ptashne had been the first to isolate the lambda repressor protein,
and his lab was in the process of investigating how it controlled
the phage’s fate. According to Meyer, he too discouraged her
from trying to tackle the question of the bacteriophage lambda’s
genetic switch. “He said, you can’t possibly compete with us, so
forget about it,” she recalls. But when she ran into him again a year
later at a conference at Cold Spring Harbor Laboratory in New
York, Ptashne asked her to sit in on meeting with a few members
of his team, where he surprised Meyer by inviting her to his lab
at Harvard to conduct the experiments on bacteriophage lambda
that she was dying to do. “I had been dreaming about this for a
whole year, and then this miracle happened,” she says.
After Echols approved the transfer, Meyer packed her bags
and moved to Cambridge, Massachusetts. Within a few weeks
of joining Ptashne’s lab, she had demonstrated that the lambda
repressor regulated the transcription of its own genes in a test tube
(PNAS, 72:4785–89, 1975). For her, this was an “aha” moment
that led to a cascade of follow-up experiments and around a dozen
papers during her PhD studies alone.
Working with Ptashne taught Meyer to be both a rigorous scientist
and an expert communicator, she says. Ptashne is “a master at figuring
out how to get messages across.... Plus, he had little patience, so your
experiments had to be perfect for him to believe them,” she tells The
Scientist. “I think that was all part of my education.”SEX AND DEATH DECISIONS
After completing her doctoral studies in 1979, Meyer wanted
to find a research question that she could make her own—and