Changes of thermal conditions mainly influence the life cycle and fitness of ectothermic species. In the parasitic wasps, Nasonia vitripennis, short exposure to heat stress during ontogenesis strongly decline the sperm production. Nasonia vitripennis is a haplo-diploid species, suggesting its offspring sex-ratio and population structure essentially depend on the male reproductive quality. Therefore, investigate how temperature fluctuations influence fitness and development of male N. vitripennis is a major concern in a context of global warming and the rearing of haplo-diploid agronomic auxiliaries.

 

This work is of high importance as although invertebrates constitute the vast majority of the animal kingdom, little effort has been made to evaluate the temperature global changes on their reproductive abilities.

 

Parasitic wasps appear to be an excellent candidate for analyzing the effects of environmental stresses on male functions. They are natural enemies of a broad range of arthropods with medical, veterinary and agricultural significance. More particularly, the wasp Nasonia vitripennis presents several advantages: first, the complete genome sequence and the iRNA tools are available. Second, due to the rapid development of this organism, the consequences of different environmental perturbations on fertility, reproductive success and F1 population dynamics are easy, cheap and fast to measure.

 

The main objectives of this project is therefore to determine the mechanisms responsible for the observed decrease in fertility of N. vitripennis males when submitted to a chemical and a thermal stress, presented either separately or in combination. Additionally, an ecotoxicogenomic approach at the transcriptomic level will allow us to characterize the gene expression variations associated to these perturbations and identify the genes pathway controlling male functions. The function of candidate genes will then be studied under these environmental perturbations. Our long-term ambition is therefore to propose N. vitripennis as lab-sentinels of potential effects on hymenopterans and a comparative model for the study of spermatogenesis regulation in mammals.