The shape of a protein that forms a key coating on an egg provides an atomic view of conception
If fertility had a shape, this would be it.
Scientists have figured out the exact shape of part of a protein that sits on the outside of the egg and aids in fertilization. The results, which may ultimately lead to new contraceptives and treatments for infertility, appear in the Dec. 4 Nature.
On its quest to fertilize an egg, a sperm cell must first get through the outer layer of the egg. Proteins composing this outer layer — called the zona pellucida — have two major jobs during fertilization. The first is to recognize that a sperm cell is from the correct species, and the second is to tighten into a solid shell that