Generally speaking as you move from traditional beef to F1 (crossbred) Wagyu to FB (fullblood) Wagyu so to moves the marbling.  Sometimes FB Wagyu is referred to as Japanese or Kobe style steaks and F1 or crossbred Wagyu are referred to as American Wagyu.  There are many variables which affect marbling of the meat from genetics to feed rations to animal husbandry.