Generation of immune specificity: a working hypothesis.

A speculative model for epigenetic generation of immune specificity is presented. It is based on the idea that combinatorial splicing within the same pre-mRNA molecule could generate a variety o mRNAs leading to a diversity of immunoglobulins. The model postulates a special role for the nuclear envelope where translation of intron sequences into messenger maturation proteins would take place. The postulates are justified and experimental implications of the model are discussed.