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Environmental Factor

Environmental Factor

Your Online Source for NIEHS News

August 2016

Fellows take top awards from reproductive society meeting

Two fellows in the lab of Humphrey Yao, Ph.D., won research and presentation awards at the Society for the Study of Reproduction meeting.

Top awards for posters and presentations come regularly for members of the NIEHS Reproductive Developmental Biology Group, headed by lead researcher Humphrey Yao, Ph.D.

The latest, awarded at the 2016 annual meeting of the Society for the Study of Reproduction (SSR) July 16-20 in San Diego, went to visiting fellow Fei Zhao, Ph.D., for his first place oral presentation. Zhao’s presentation addressed an early stage of reproductive tract development that is essential for forming sex-specific functional reproductive organs. He discussed the latest results of his team’s ongoing research (see text box).

In addition, Zhao and his colleague, Kathryn McClelland, Ph.D., also a visiting fellow in Yao’s group, both received Lalor Foundation Merit Awards at the meeting. Each of these awards, which recognize the seven best-researched and most well-presented abstracts, includes a $500 stipend for career development.

When NIEHS and National Toxicology Program Director Linda Birnbaum, Ph.D., learned of the awards, she responded, “That is wonderful!” NIEHS Scientific Director Darryl Zeldin, M.D., joined others from his office in congratulating the winners. NIEHS Reproductive and Developmental Biology Laboratory (RDBL) Director Kenneth Korach, Ph.D., added high praise for Yao’s mentoring.

SSR is a global association of scientists and clinicians with the mission of promoting outstanding research and training in reproductive sciences, with the goal of protecting and preserving human and animal reproductive health.

The selection process for the awards is rigorous, honoring the best oral and poster presentations from more than 450 abstracts submitted by predoctoral and postdoctoral fellows.

NIEHS takes pride in training and mentoring

The SSR awards are not the first for Zhao and McClelland during their time as fellows at NIEHS.

Earlier this year, Zhao won a best trainee poster award at the 25th annual meeting of the Triangle Consortium for Reproductive Biology, where McClelland also made an oral presentation (see story). He was recognized this year with the NIH Summer Research Mentor Award, and he received a Larry Ewing Memorial Trainee Travel Fund award at the SSR annual meeting in 2015.

Yao, who won the same SSR Trainee Research Award in 1999 during his predoctoral fellowship, clearly understands the importance of participation in professional development activities for his trainees. As part of RDBL, members of Yao’s group also make presentations on their research projects and undergo critiques by lead researchers and fellow trainees.

“I am very lucky to be able to receive my postdoctoral training with RDBL,” Zhao said. “Dr. Yao is a great mentor who instructs me and helps improve my presentation skills. His mentoring helped me reach the high level that wins such an award.”

(Eddy Ball, Ph.D., is a contract writer with the NIEHS Office of Communications and Public Liaison.)

Orchestrating development of reproductive organs

Part of the main focus of Yao’s lab is to define the normal process of gonad and reproductive tract formation as the embryo develops. The group studies how this process is susceptible to in utero exposure to endocrine disruptors, and how abnormalities may result in birth defects and later fertility problems.

During sexual differentiation, an embryo with both female and male reproductive tracts develops the tract that corresponds to its sex and eliminates the other. Conventional wisdom in the field of reproductive biology holds that the maintenance of the male reproductive tract, or the Wolffian duct, depends exclusively on the action of the testicular hormone androgen. In the absence of androgen, as in the female embryo, the Wolffian duct regresses. Elimination of the male reproductive tract in the female is believed to be a passive outcome of the lack of androgen.

Zhao and colleagues identified a novel transcription factor expressed exclusively in cells surrounding the Wolffian duct. They hypothesized that it acts as a mechanism to actively promote Wolffian duct elimination. Using genetically modified mice, which do not produce that transcription factor, they found that the Wolffian duct was maintained in female embryos, although it was supposed to regress from the lack of androgen.

They also gained insight into the mechanisms and pathways involved by examining gene expression using microarray analysis. The team found an upregulation of fibroblast growth factors that are normally suppressed by the novel transcription factor, and its upregulation in the female prevented elimination of the Wolffian duct.

The researchers concluded that elimination of the male Wolffian duct is the result of active work by the transcription factor, rather than a passive outcome of the absence of androgen.

Citation: Zhao F, Franco HL, Rodriguez K, Brown P, Tsai M-J, Tsai SY, Yao HC. 2016. Wolffian duct regression in the female embryo is the result of COUP-TFII action, not a lack of androgen action. (Abstract published on page 113 of the SSR 2016 Scientific Program.)

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