Printed in Great Britain Ontogenetic changes in hemoglobin synthesis of two strains of Chironomus tentans

Differentiating cells can be characterized by the number and types of proteins they produce (Markert, 1963). In man and other organisms the diversity of hemoglobins has been correlated with ontogenetic changes which reflect the alterations of gene activity (Ingram, 1963). Furthermore, the types of proteins produced are generally specific for the species. The study of insect coelomic proteins has followed closely that of mammalian serum protein analysis; however, profound differences exist between human blood and insect coelomic fluids. For this reason, the term 'hemolymph', rather than blood, has been used to designate these fluids. Svedberg & Eriksson-Quensal (1934) first studied the ultracentrifuge properties of Chironomusplumosus hemoglobins and determined them to have a molecular weight of 34000. Braunitzer & Braun (1965) described the multiplicity of hemoglobins in Chironomus thummi and claimed two subunits per molecule. Man well (1966) suggested the hemoglobins of Chironomus plumosus possessed a monomeric structure. Thompson, Bleecker & English (1968) demonstrated the monomeri