This series is designed to provide a forum for discussion of new discoveries, approaches and ideas in molecular biology. It includes contributions from leaders in their fields. Although it should be of interest to molecular biologists in particular, it should also appeal to a wider circle of biologists and all those who are concerned with the living cell. This volume examines such topics as immunoglobulin gene diversification by gene conversion; molecular biology in the eicosanoid field; and tRNA structure and aminoacylation efficiency.