SAN FRANCISCO - The future of embryonic stem cell research could be shaped in a suburban courtroom where two taxpayer groups are challenging the legality of California's new agency dedicated to the controversial field. Opening statements were scheduled for Monday in a pair of lawsuits seeking to invalidate the law that created the California Institute of Regenerative Medicine, which is authorized to hand out $3 billion in research grants. The lawsuits allege — among other things — that it violates a state constitutional mandate that the spending of taxpayer dollars be under state control. "The act delegates the disbursal of...