News Archive

BTI Postdoc’s Paper Cited in Nature’s Research Highlights

Feb 2, 2006

Yoshiki Nishimura, now a postdoctoral fellow in David Stern’s lab, is the lead author of the paper, which appears in the Proceedings of the National Academy of Sciences. The experiments were performed while Yoshiki was a graduate student at the University of Tokyo. The Research Highlights item is reprinted here:

Cell Biology: Mitochondrial massacre

Researchers in Japan have watched sperm mitochondrial DNA being destroyed in the egg immediately after fertilization.

Offspring inherit almost all of their mitochondria, which provide cells with energy, from their mother. This was long assumed to be because the handful of mitochondria delivered by the small sperm are diluted by the large egg’s abundance of these organelles. But real-time observations made by Yoshiki Nishimura and his team back up reports that paternal mitochondrial DNA (mtDNA) is instead actively digested.

By fluorescently labelling the paternal mtDNA in fish, the researchers showed that it is broken down within hours of fertilization. This may prevent the embryo from inheriting paternal mtDNA that was damaged during sperm production.

Reprinted by permission from Macmillan Publishers Ltd: Nature 439, 512-513, copyright 2006.

Reference: Nishimura, Y., T. Yoshinari, K. Naruse, T. Yamada, K. Sumi, H. Mitani, T. Higashiyama and T. Kuroiwa (2006). Active Digestion of Sperm Mitochondrial DNA in Single Living Sperm Revealed by Optical Tweezers. Proceedings of the National Academy of Sciences 103(5): 1382-1387.