SAGE Labs, a Maryland Heights-based laboratory that provides animal models to the research community, will be acquired by United Kingdom life science company Horizon Discovery Group in a deal that could reach $48 million. Horizon is acquiring SAGE for $16 million in cash and $32 million in stock. The deal is expected to close on Thursday. The deal comes one week after Sigma-Aldrich, SAGE's former parent company, was acquired by German pharmaceutical and chemical company Merck KGaA for $17 billion. SAGE…