Diana Chu identifies key factors in healthy sperm production

SAN FRANCISCO, August 30, 2006 -- A San Francisco State University biology professor's research on the DNA in the sperm of tiny worms will shed new light on the causes of human male infertility. Diana S. Chu is lead author on the paper, "Sperm Chromatin Proteomics Identifies Evolutionarily Conserved Fertility Factors," which identifies new proteins critical to the production of healthy sperm. Appearing today in the journal Nature's Advance Online Publication, [http://www.nature.com] the paper will be published in the journal's Sept. 7 print issue.

Chu's research at SF State focuses on male infertility as a major contributor to reproductive failure in the United States. She used the tiny worm Caenorhabditis elegans as the model species to find the factors that play an important role in assembling the DNA content of sperm. Her identification of factors that function in fertility and reproduction could define new avenues for understanding human male infertility, finding appropriate treatments, and/or identifying new contraceptive methods.

"The idea behind this research came from the observation that worm sperm DNA is very highly compacted, similar to the way it is in humans," Chu said. "We decided to find proteins that associate with sperm DNA and found that they are important for fertility in C. elegans."

Importantly, Chu also found that the majority of the worm proteins have similar counterparts in mice and humans, and that some of the mice proteins also are required for fertility. Because researching molecular causes of male infertility directly in humans is technically difficult, using a simple model organism, like C. elegans, offers great potential to address some of the undefined causes of human male infertility.

Chu initiated this work in the laboratory of Barbara J. Meyer at the University of California, Berkeley. Other colleagues on this research were Tammy F. Wu, also of SF State; Hongbin Liu and John Yates III of The Scripps Research Institute; and Edward J. Ralston and Paola Nix of University of California, Berkeley.

A resident of Belmont, Calif., Chu received her Ph.D. in Molecular Biology at University of California, Los Angeles and B.A. at the University of California, Berkeley.

SF State is the only master's-level public university serving the counties of San Francisco, San Mateo and Marin. The University enrolls about 29,000 students each year and graduates about 7,000 annually. With nationally acclaimed programs in a range of fields -- from creative writing, cinema and biology to history, broadcast and electronic communication arts, theatre arts and ethnic studies -- the University's more than 150,000 graduates have contributed to the economic, cultural and civic fabric of San Francisco and beyond.