The Secret Life of Sperm

Nature has a neat article summarizing recent results coming from the new light being shed on sperm. Long thought of just the "delivery boys" for male DNA to the egg, studies are now questioning whether there isn't more going on in the sperm. The studies promise to bring further understanding to fertility and the evolution of sex. Studies are showing that defects in sperm can result in the disruption of embryo development and could be a cause for miscarriages. Sperm can be broken into three sections: the tail, that propels the sperm to its destination; the mid-section that has an array of mitochondria to power the tail; and the head, that contains the DNA, but also messenger RNA and proteins. It's the RNA and proteins that are causing researchers to question their understanding of sperm. When the sperm enters the egg, the entire sperm goes in -- tail and all. It isn't only the DNA that is released into the egg, but also the RNA and proteins. The proteins that get delivered by sperm, and the protein that the RNA is coded for, seems to be important for embryo development and affects the activities of genes. Some of the RNA delivered by the sperm are unique -- not existing in the egg already. This has led researchers to conclude that the sperm is more than just a DNA delivery mechanism, but an active participant with the egg in creating and developing the embryo -- new findings that are showing just how miraculous life really is.