The role of factors from the head in the regulation of egg development in the mosquito Aedes aegypti
| Autor: | Henry H. Hagedorn, R.L. Glaser, J.T. Greenplate |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
medicine.medical_specialty
Ecdysteroid animal structures food.ingredient Physiology Radioimmunoassay Aedes aegypti Biology biology.organism_classification Blood meal Oocyte Oogenesis Vitellogenin chemistry.chemical_compound food Endocrinology medicine.anatomical_structure chemistry Insect Science Yolk Internal medicine biology.protein medicine |
| Zdroj: | Journal of Insect Physiology. 31:323-329 |
| ISSN: | 0022-1910 |
| DOI: | 10.1016/0022-1910(85)90009-5 |
| Popis: | The relationships between the release of factors from the head after blood-feeding, subsequent levels of ecdysteroids and vitellin, and the ultimate maturation of eggs in Aedes aegypti were investigated. Females were decapitated at various times after a blood meal, at 20 or 48 h after feeding the animals were dissected and divided into two groups, those with arrested oocytes (yolk length 100 μm). These yolk lengths correspond with the levels of oocyte growth believed to accompany the proposed initiation and promotion phases of egg development. Animals dissected at 20 h were assayed for ecdysteroid by radioimmunoassay; those dissected at 48 h were assayed for vitellin by rocket immunoelectrophoresis. Non-blood-fed unoperated females contained 8% as much ecdysteroid as blood-fed controls and no measurable vitellin. Females with arrested oocytes (< 100 μm) were obtained only if decapitations were performed before 8 h; these females had about 20% of the ecdysteroids and 8% of the vitellogenin normally found in blood-fed animals. Females decapitated between 2 and 8 h with maturing oocytes contained 50–60% as much ecdysteroid and vitellin as blood-fed unoperated controls. Normal ecdysteroid and vitellin levels were reached only when decapitations were delayed for 12 and 24 h, respectively. The number of developing oocytes was also decreased by early decapitation and was closely correlated with vitellin levels. We conclude that the egg development neurosecretory hormone is released twice, once before 8 h and once after 8 h, to control ecdysteroid levels. We also suggest the presence of other factors from the head that control vitellin levels, the number of developing oocytes, and the early growth of the oocyte (initiation). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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