Wednesday, May 4, 2011

From Silent Spring to Silent Night: A Tale of Toads and Men

As the semester winds down here at Fresno State, the Tri Beta Biology Club has a couple more special treats for us. For this week's Biology Colloquium, we bring you a real role model in Dr. Tyrone Hayes, an African American field biologist (yes, they exist, despite the stereotype) who became one of the youngest Full Professors at the University of California Berkeley. He will share his groundbreaking (and corporation-shaking) research on the effects of the herbicide Atrazine on amphibians, a taxon that has been in global decline for some time now, with pesticides hammering some of the nails in their collective coffin. Here's an excerpt about Dr. Hayes' work from the PBS documentary Frogs: The Thin Green Line:

And if that isn't enough to grab your interest, this might:

Here are details of the colloquium:

Tri Beta Biology Club presents:


Dr. Tyrone Hayes
Professor of Integrative Biology
University of Californa, Berkeley

on Friday, May 6, 2011
at 3:00 PM in AG 109 (download maps here)

The herbicide, atrazine, is a potent endocrine disruptor. My laboratory’s studies in amphibians have shown that atrazine both demasculinizes and feminizes exposed males at levels as low as 0.1 ppb. Our previous worked examined morphological effects, including the loss of androgen-dependent sexually dimorphic features, and the development of estrogen-dependent features in exposed males. These findings are consistent with an induction of aromatase, resulting in decreased androgen secretion and inappropriate estrogen synthesis and secretion. Our ongoing studies focus on behavioral effects in male frogs exposed throughout life and demonstrate both the loss of male reproductive behavior and the induction of female-typical behavior in exposed males. These data on amphibians and the proposed mechanism are consistent with findings across vertebrate classes, including humans, and raise concern about the role of this common environmental contaminant in reproductive hormone-dependent cancers and declining fertility in humans.

Call the Biology department (559•278•2001) for more information. You can also download the flyer here.

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