CHAPEL HILL - In a study of life's beginnings, scientists at the University of North Carolina at Chapel Hill have moved a step closer to unraveling the biochemical mystery of embryogenesis, the process by which an egg cell transforms into an embryo.
At the heart of this new research is a pair of cellular proteins - SLBP1 and SLBP2 - which were identified in frog oocytes (immature egg cells) by researchers headed by Dr. William F. Marzluff, professor of biochemistry and biophysics at UNC-CH School of Medicine. In a report of the findings published in January's Molecular and Cellular Biology, Marzluff and his study colleagues suggest that the proteins act as separate "on" or "off" biochemical switches that trigger synthesis of histone proteins crucial to normal cell functioning during embryogenesis and throughout the organism's life. About half of the nucleoprotein complex known as DNA are histone proteins.
Although the new study looked at frog oocytes - largely because of their accessibility in large quantities - proteins structurally similar to SLBP1 have been identified in other organisms, including worms, flies, and mice, according to Dr. Thomas C. Ingledue, a postdoctoral fellow in Marzluff's laboratory. Ingledue is a lead co-author of the report along with Dr. Zeng-Feng Wang, formerly of UNC-CH and now with the Carnegie Institute of Embryology. "The new findings are already focusing our studies on other model systems, including mammalian," Ingledue says.
Studies have established that all genes are inactive - turned off - during early
embryogenesis. In frog cells, they remain off until the embryo has gone through
12 rounds of division. "And if you don't activate genes during development but
you have a need for a large amount of proteins to be used during development,
then you better have those proteins stored. Or you better be ready to translate,
or activate, stored RNA to make those proteins," Ingledue explains. "That's what
the crux of our work
Contact: Lynn Wooten
University of North Carolina School of Medicine