Alternative Splicing of the Xmas mRNA Encoding the mRNA Export Protein in Drosophila melanogaster.

It is shown that Drosophila melanogaster has Xmas mRNA whose alternative splicing leads to the formation of three transcripts: Xmas, Xmas-2, and Xmas-1. As a result, three proteins are synthesized: Xmas, Xmas-2, and, presumably, Xmas-1. The size of the Xmas protein is close to the size of its homologue in humans.

A new type of organization of the genetic material in eukaryotes.

An investigation of the properties of a number of genes of Drosophila, obtained by cloning recombinant DNAs, led to the detection of a new type of organization of genetic material. It was found that a number of actively working structural genes of Drosophila are represented by a large number of copies, scattered over its chromosomes. Their localization in the chromosomes is variable, although they are always detected in regions of intercalary heterochromatin.