CHROMOSOME ACTIVITY AND BIOCHEMICAL CELL DIFFERENTIATION IN SALIVARY GLANDS OF CAMPTOCHIRONOMUS

Salivary glands of Camptochironomus tentans and C. pallidivittatus were used to study the question whether genes controlling the synthesis of characteristic cell proteins are located in chromomeres specifically puffed in this tissue. Salivary gland cells produce considerable amounts of secretory proteins. In G. tentans, this secretion was shown by gel electrophoresis to consist essentially of 5 protein subunits. In C. pallidivittatus, a component (no. 6) additional to these was found. Another constituent of the secretion (no. 7) is synthesized in C. pallidivittatus by only a small group of gland cells. - The inheritance of these species- and cellspecific proteins has been investigated by relating their presence in interspecific hybrids to the chromosome constitution. Fraction no. 6 was found to be correlated to a short distal region of chromosome IV in which a tissue-specific Balbiani ring is located. Secretion component no. 7 which is characteristic of the special gland lobe of C. pallidivittatus is also controlled by chromosome IV which in this lobe develops a cell-specific Balbiani ring. © 1969 Springer-Verlag.