Druckansicht der Internetadresse:

BayCEER - Bayreuth Center of Ecology and Environmental Research

print page

Endocrine control of egg size in the tropical butterfly Bicyclus anynana

Grako678 A2

From 01/2004 to 12/2005

Principal Investigator: Klaus H. Hoffmann
Grant: GK 678/2 Graduate College 678: Ecological Significance of Natural Compounds and other Signals in Insects - from Structure to Function

Egg size is an especially interesting life history trait because it simultaneously affects maternal and progeny fitness. Consequentially is egg size subject to selection in both, the parental and progeny generations. Life history theory predicts a trade-off between egg size and the number of eggs, and that progeny fitness increases with increasing parental investment per offspring. Both assumptions are in general supported by empirical evidence. Thus, egg size has been found to vary among species, populations within species, females within populations and among the progeny produced by a single female. To date, however, few empirical studies have progressed much beyond documenting patterns of variation in progeny size, and our knowledge on the specific factors involved in variation of progeny size is still poor. Therefore the main focus of this dissertation will be the physiological and molecular mechanisms of the hormonal control of egg size variation in the model organism, Bicyclus anynana. Because juvenile hormones (JHs) are known to have pleiotropic effects on many insect life history traits including e.g. the onset of reproduction, fecundity and vitellogenesis, JHs will be of major interest. As a first step JH-titres in the haemolymph of adults and pupae from lines selected for large respectively small egg size will be determined by using LC/MS. Time series will help to identify the sensitive phases. Furthermore, the role of neuropeptides (allatotropins, allatostatins) in controlling JH-titres will be investigated.

Homepage: http://www.uni-bayreuth.de/grako678/media/Projekte_neu.htm

This site makes use of cookies More information