Hormones synthesized by the insect corpus allatum. The titer of allatum hormones influences the qualitative properties of each molt in holometabolous insects. At high concentrations, larval development ensues; at lower levels, the insect undergoes pupal metamorphosis, and in the absence of the allatum hormones adult differentiation takes place. The allatum hormones thus have a juvenilizing action and for this reason have also been called juvenile hormones (JHs). The structural formulas for three of the juvenile hormones are illustrated below. In adult females, the allatum hormone is required for vitellogenesis. The JH analog, ZR515 (q.v.), is often used as a substitute for natural JHs in Drosophila experiments. See Chronology, 1966, Röller et al.; ring gland, status quo hormones.
Subjects: Genetics and Genomics.