GNOME seems to use the Dejavu font to render certain user interface symbols, particularly the arrows on the login screen (next to "Session") and the GNOME panel menus.
Fixed, thanks. > 10 Oct 2012; Alexandre Rostovtsev <tetromino@gentoo.org> > gnome-shell-3.2.2.1.ebuild, gnome-shell-3.4.1.ebuild, > gnome-shell-3.4.2.ebuild: > Depend on dejavu font for special symbols used in the shell UI (bug #437734, > thanks to Jacob Godserv).