Increased juvenile hormone levels after long-duration flight in the grasshopper, Melanoplus sanguinipes
| Autor: | Kyung-Jin Min, David W. Borst, Nathan T. Jones, Mary Ann Rankin |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
medicine.medical_specialty
Time Factors Physiology media_common.quotation_subject Oviposition Physical Exertion Insect Grasshoppers Internal medicine Hemolymph medicine Animals Adipokinetic hormone Grasshopper media_common Analysis of Variance biology Reproductive success biology.organism_classification Circadian Rhythm Pyrrolidonecarboxylic Acid Juvenile Hormones Titer Endocrinology Insect Science Flight Animal Insect Hormones Juvenile hormone Reproduction Carboxylic Ester Hydrolases Oligopeptides Sesquiterpenes |
| Zdroj: | Journal of insect physiology. 50(6) |
| ISSN: | 0022-1910 |
| Popis: | Although, in many insects, migration imposes a cost in terms of timing or amount of reproduction, in the migratory grasshopper Melanoplus sanguinipes performance of long-duration flight to voluntary cessation or exhaustion accelerates the onset of first reproduction and enhances reproductive success over the entire lifetime of the insect. Since juvenile hormone (JH) is involved in the control of reproduction in most species, we examined JH titer after long flight using a chiral selective radioimmunoassay. JH levels increased on days 5 and 8 in animals flown to exhaustion on day 4 but not in 1-h or non-flier controls. No difference was seen in the diel pattern of JH titer, but hemolymph samples were taken between 5 and 7 h after lights on. Treatment of grasshoppers with JH-III mimicked the effect of long-duration flight in the induction of early reproduction. The increased JH titer induced by performance of long-duration flight is thus at least one component of flight-enhanced reproduction. To test the possibility that post-flight JH titer increases are caused by adipokinetic hormone (AKH) released during long flights, a series of injections of physiological doses of Lom-AKH I were given to unflown animals to simulate AKH release during long flight. This treatment had no effect on JH titers. Thus, although AKH is released during flight and controls lipid mobilization, it is not the factor responsible for increased JH titers after long-duration flight. |
| Databáze: | OpenAIRE |
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