https://phys.org/news/2018-10-protein-thousands-genes-essential-sperm.html

Germ cells are extraordinary—they become sperm and eggs and ultimately an organism's progeny. Male germ cells in particular must replicate again and again over the course of a man's life. "This specialized cell requires unique regulation and control of gene expression," said Zagore "Dazl functions as a master regulator. It promotes the correct levels of other proteins that, in turn, control many essential processes within growing sperm, including proliferation and cell survival."

Although Dazl binds to thousands of RNAs, not every interaction is meaningful, say the researchers. "Dazl binds a very simple sequence in RNA, a string of three RNA bases (G-U-U), which occurs all over RNA fragments. But we found G-U-Us that are directly bound by Dazl are highly concentrated in a specific spot on RNAs," said Zagore's advisor Donny Licatalosi, Ph.D., assistant professor in the Center for RNA Science and Therapeutics at Case Western Reserve University School of Medicine. "This spot occurs right before the 'polyA tail' found at the end of nearly all messenger RNAs, which are templates to make proteins."