Post meiotic nucleo-cytoplasmic interaction in Pinus banksiana: The secretion of RNA by the nucleus.

Using digestion with specific enzymes, the chemical nature has been resolved of components of the nuclear invaginations formed in post-meiotic microspores of Pinus banksiana (Lamb.). The content of the invaginations is formed almost entirely of RNA, while the main bulk of the granular material investing the narrow part of the invaginations is also RNA. The membranes composing the narrow portion of the invaginations are themselves sensitive to RNase.These data are considered as supporting further the hypothesis that the invaginations are involved in the passage and organisation of information-carrying macromolecules.