What is the fine-grained topic of the following text: Differences in genes involved in the biosynthesis of lipopolysaccharide O side chains between the Copenhageni and Lai serovars were identified, offering an important starting point for the elucidation of the organism’s complex polysaccharide surface antigens. Only return the topic.
Differences in genes involved in the biosynthesis of lipopolysaccharide O side chains between Copenhageni and Lai serovars.