Variability in Juvenile Hormone production by locust corpora allata kept in vitro for long periods |
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Authors: | M. GADOT M. P. PENER C. SCHAL |
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Affiliation: | Department of Cell and Animal Biology, The Hebrew University of Jerusalem, Israel;*Department of Entomology, Cook College, Rutgers University, New Brunswick, New Jersey, U.S.A. |
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Abstract: | Abstract. Juvenile Hormone III (JH-III) production by corpora allata (CA) of sexually mature female locusts (Locusta migratoria migratorioides (R. & F.)) was maintained in vitro for up to 30 days in an agar-solidified medium. Hormone production was measured periodically with a short-term radiochemical assay. Low-activity CA increased their activity significantly after 24–48 h incubation in the long-term medium, but high-activity glands did not. Variations in activity were considerable among glands tested on the same day and among measurements from the same gland on different days. Farnesoic acid-stimulated rates of JH-III production were always higher than the basal rates, suggesting that the CA were not maximally activated. However, freshly excised low-activity CA, whose hormone production increased in the long-term conditions, showed similar farnesoic acid-stimulated rates of JH-III production to those of freshly excised high-activity glands, suggesting that at the time of excision of the corpora allata rate-limiting step(s) preceding farnesoic acid biosynthesis were inhibited or refractory to stimulation in vivo. |
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Keywords: | Locusta migratoria corpora allata long-term incubation Juvenile Hormone biosynthesis. |
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