Jon Nelson, Howard Hughes Medical Institute (image) Howard Hughes Medical Institute Share Print E-Mail Caption Jon Nelson, a researcher in Yukiko Yamashita's group, uses fruit flies (in flasks at right) to study the role of rDNA in aging. Credit Yukiko Yamashita Usage Restrictions Must use with credit. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.