Roundworm gonad (IMAGE) Northwestern University Caption Precursor egg cells (shown in blue) inside a female roundworm's gonad. Fluoxetine (Prozac) increases division of germline precursor cells (shown in magenta) in worms. Credit Ilya Ruvinsky/Northwestern University Usage Restrictions add credit License Original content 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.