Cover image: Fruit fly factory. Each ovary of the female fruit fly houses multiple ovarioles or
“assembly lines” in which individual egg chambers develop into fully formed fly eggs. Each egg
chamber consists of 16 large germline cells (one of which is the future egg cell), surrounded by
a thin sheet of smaller cells. In this picture, cross-sections of 10 ovarioles from different female
fruit flies are arranged with stem cells and early-stage egg chambers at the center and the more
mature chambers at the periphery. The nucleus of each cell is stained yellow/orange. The cell
membranes are stained blue. Image by Yogesh Goyal, Bomyi Lim, Miriam Osterfield, Stas
Shvartsman, Princeton University. Winner of “People’s Choice” award, Princeton University
2014 Art of Science Competition. See all images online at artofsci.princeton.edu. Reprinted with
permission from Princeton University.