Variation of isocytochromes [formula omitted] during metamorphosis of the housefly, Musca domestica L.

Abstract

Two isocytochrome c 's occur in the housefly, Musca domestica L. and their primary structures differ in at least five positions ( Yamanaka et al., 1980). The amount of the major isocytochrome in larvae (larval-type cytochrome c) decreased by 50% on pupation, decreased by a further 50% at the late pupal stage (one day before adult emergence) and then increased two-fold on adult emergence. The major isocytochrome in adults (adult-type cytochrome c) also occurred in larvae. The amount of this isocytochrome remained constant through the larval and early pupal stages, increased approximately 3.7-fold at the late pupal stage and further increased by approximately 6.3-fold on adult emergence; its amount in adults was more than twenty times that in larvae. Thus the increase in the total amount of cytochrome c seen during the metamorphosis of the housefly was caused mainly by the increased biosynthesis of adult-type cytochrome c, however the larval-type cytochrome did not disappear completely in the adult flies. The ratio in the amount of adult- to larval-cytochrome c 's varied in different areas of the adult fly; the ratio was approximately 3.6 in the thoraces while it was approximately 0.3 in the abdomens.