Hawley Lab

Scott Hawley, Ph.D.

Investigator and American Cancer Society Research Professor

Dean, The Graduate School of the Stowers Institute

Professor of Molecular and Integrative Physiology
   School of Medicine, University of Kansas Medical Center

Adjunct Professor, School of Biological Sciences
   University of Missouri at Kansas City

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A quote heading Scott Hawley’s resume reads, “There are three functions of a scholar: to learn, to write and to teach.” In truth, some scholars prefer to concentrate on the first two. But Hawley’s recent induction into the National Academy of Sciences for groundbreaking research in meiosis proves that training future scientists is no roadblock to a distinguished research career.


Drosophila germarium showing the enrichment of the Trem protein (shown in green), which plays a role in the meiotic recombination pathway, in region 1 and the accumulation of C(3)G (shown in red), which ispart of the synaptonemal complex, beginning in region 2A. Cell nuclei are shown in blue.

Image: Hawley lab

In fact, to Hawley, a Stowers Investigator and American Cancer Society Research Professor, engaging undergraduates has only enhanced his career as a Drosophila geneticist. “Teaching is like breathing—it is not dispensable,” says Hawley. “To re-examine my craft once or twice a year and then present it to people who do not yet understand it is a huge honor.”

Hawley’s “craft” is to define how the two highly specialized cell divisions that halve chromosome number to form eggs are orchestrated molecularly. He has been practicing it for over three decades using the fruitfly Drosophila melanogaster as a model system, starting as an undergrad at University of California at Riverside (UCR).
 
But Hawley initially wanted to be a lawyer. He was inspired by 60’s reformers like Martin Luther King, Cesar Chavez and Betty Friedan and by Clarence Darrow, who had defended the legality of teaching evolution in the famous Scopes “monkey trial”. Hawley had been diagnosed with epilepsy as a teenager and as a result was exposed firsthand to the needs of children with disabilities. “At that time people were fighting for various causes but I did not see much concern for people with disabilities,” Hawley says.
 
But an influential teacher, Crellin Pauling, son of two-time Nobel laureate and chemist Linus Pauling and then a genetics professor at UCR, suggested a different way to help the disabled. “Crellin said, ‘If you want to make a difference, do something about birth defects. Right now there may not be much we can do, but at least take a genetics course,’” recalls Hawley.
 


A Drosophila prometaphase I oocyte.  Non-exchange X chromosomes and non-exchange chromosomes 4 are shown in blue, the spindleapparatus is stained red and chromatin, including the chromatin threads connecting non-exchange chromosomes, is labeled in green.

Image:  Hawley lab

Hawley changed his major to biology, did undergraduate research in the lab of Drosophila geneticist Dean Parker, and published his first paper on the effects of radiation-induced chromosome breaks on meiosis in 1975. “Dean Parker was a scholar,” says Hawley. “He spoke nine languages and his hobbies included translating fairy tales from Dutch into English. I loved working in his lab.”
 
From then on—through graduate school in the lab of geneticist Larry Sandler at University of Washington to a Helen Hay Whitney Fellow postdoctoral fellowship with Ken Tartof at the Institute for Cancer Research in Philadelphia—Hawley continued to define mechanisms controlling what he in one review calls “the meiotic ballet” and never considered being anywhere but a lab or classroom.
 
Before joining Stowers in 2001, Hawley held faculty positions first at Albert Einstein College of Medicine in New York and then at University of California at Davis, a position he took in part because he missed teaching undergraduates.
 
At Stowers he has focused on three questions relevant to how meiosis progresses: how chromosomes in Drosophila female cells pair up and swap sequences (recombine), how they separate into two daughter cells at the critical first meiotic division, and how that program including a second division is coordinated, producing eggs, or oocytes, with half the complement of the correct chromosomes.
 
To address the first, the group defined factors that govern the initiation of homologous chromosomal recombination, a process in which regions of homologous chromosomes  “cross over” with each other, and in doing so, become physically locked together. They recently found that a chromosome-binding protein called Trade Embargo defines the first step in initiating recombination, providing clues as to how recombination is initiated.
 
The group has also used live imaging to watch chromosomes in real time position themselves as meiosis begins, an alignment critical for successful segregation into daughter cells. In related studies they identified how the protein Nod nudges chromosomes into proper alignment prior to that crucial first meiotic division. As Hawley points out, “all of Mendelian genetics is explained by the first meiotic division”
 
Finally, the group has shown the egg protein Matrimony controls the timing of a number of critical meiotic events by  directly blocking the activity of a kinase called Polo that controls meiotic progression.  
 


Zygotene nucleus of a planarian spermatocyte. The meiosis-specific protein Hop1 is shown in green and Rad51 is shown in red. DNA is stained blue with DAPI.

Image:  Hawley lab

In Hawley’s lab, undergraduates significantly contribute to research projects, a function usually dominated by postdocs and graduate students. “Flies are a good system for undergrads to learn in,” says Hawley. “You can do genetics without knowing a bunch of chemistry or cell biology. AND genetics always works: you cross a pair of flies and you get progeny!”
 
Hawley teaches undergrads, graduate students, and even a few medical students in classrooms atthe University of Kansas and the University of Missouri. In recognition of his commitment to undergraduate education, Hawley received the 2008 Elizabeth W. Jones Award for Excellence in Teaching from the Genetics Society, which also elected him president in 2010.
 
In the meantime, Hawley has published six books, including The Human Genome: A User’s Guide, conceived when Hawley taught a genetics class for non-majors at UC Davis, and Drosophila genetics texts.
 
He is also working on a novel, which he predicts will be published posthumously, and writes poetry. Thus far his published poetry resides in the titles of some of his scientific writings. Among them are: “Allpaired up with no place to go: pairing, synapsis, and DSB formation in a balancer heterozygote”, “Matrimony ties Polo down: can this kinase get free?” and “The hows and Ys of genomic integrity,” a comment on structural oddities and beauty of the Y chromosome. 
 
Although we can’t know what kind of lawyer Hawley would have made, it is almost a certainty that his studies of egg generation in Drosophila will contribute to human reproductive capacity. “We understand meiosis better than I ever thought imaginable and have created models to test causes of maternal age effects,” he says, referring to the fact that meiotic anomalies, which often result in miscarriage or birth defects, are more common in 45- than in 25-year-old women. “Our work provides vital tools and ideas for exploring the function of that system.”