Allocation of more reproductive resource to egg size rather than clutch size of gregarious desert locust (Schistocerca gregaria) through increasing oogenesis period and oosorption rate
| Autor: | Koutaro Maeno, Saïd Ghaout, Cyril Piou |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
Avian clutch size
food.ingredient Physiology Period (gene) Zoology Grasshoppers Oogenesis food Yolk medicine Animals L53 - Physiologie animale - Reproduction Desert locust Schistocerca gregaria Ravageur des plantes Comportement reproductif biology Reproduction Clutch Size Oocyte biology.organism_classification H10 - Ravageurs des plantes Ovogénèse medicine.anatomical_structure Insect Science Physiologie animale Oocytes Female Schistocerca Vitellogenesis Reproduction animal |
| Zdroj: | Journal of Insect Physiology |
| ISSN: | 0022-1910 |
| DOI: | 10.1016/j.jinsphys.2021.104331 |
| Popis: | The desert locust, Schistocerca gregaria, shows density-dependent reproductive trade-off by laying fewer but larger eggs in crowded conditions (gregarious phase) than in isolated conditions (solitarious phase). However, the physiological mechanisms controlling reproductive resource allocation remain unclear. We examined how egg production processes, including ovulation timing (i.e., oogenesis period), oocyte and ovarian growth rates, and oosorption rate (resorbing developing terminal oocytes), regulate reproductive outputs (egg biomass per clutch, egg size, and clutch size) during a reproductive cycle in S. gregaria by rearing them either under isolated or crowded conditions. We observed a common density-dependent negative correlation between egg size and clutch size, with no significant difference in egg biomass between the two rearing conditions. Dissection of female locusts after different days of oviposition revealed that the daily oocyte growth rate was almost similar between the two rearing conditions, but crowd-reared females ovulated later than isolated-reared ones, resulting in further oocyte growth in the former. Terminal oocytes were renewed by previous penultimate oocytes at the onset of a new reproductive cycle, and oosorption mainly occurred at an early stage in both rearing conditions; however, crowd-reared locusts displayed higher levels of oosorption compared to their isolated-reared counterparts. Crowding induced a high oosorption rate, resulting in a reduced clutch size and a prolonged oogenesis period, which in turn allowed oocytes to intake more yolk, which was probably recycled via oosorption. These results suggest that the length of the oogenesis period and oosorption rate are manipulated by maternal density, and these physiological modifications interactively regulate reproductive trade-off in S. gregaria. |
| Databáze: | OpenAIRE |
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