In the larvae of the mosquito Aedes aegypti, the three most important endocrine glands, the corpora allata (CA), the corpora cardiaca (CC), and the prothoracic gland (PG), together form the glandular complexes (GC). Using confocal laser scanning microscopy in combination with immunohistochemistry, in situ hybridization, ultrastructural expansion microscopy, and apoptosis studies, we were able to identify the different cell types of the GC and follow their fate during metamorphosis. Our studies revealed that the CC is not a well-defined organ but consists of individual cells randomly distributed within the GC and CA-CC complexes. Furthermore, imaging and in situ hybridization show that the CA is a compact organ composed of a single cell type. We observed that CA and CC survive during the larval-to-adult transition, while PG undergoes apoptosis and disappears within the first 24 h of adult life. This study lays the foundation for a more detailed understanding of the structure and changes in the major endocrine organs of mosquitoes, which are vectors of several important infectious diseases.

Department of Biological Sciences and BSI Florida International University Miami FL 33199 USA

Faculty of Science University of South Bohemia 370 05 České Budějovice Czech Republic

Institute of Entomology Biology Centre Czech Academy of Sciences 370 05 České Budějovice Czech Republic

Institute of Parasitology Biology Centre Czech Academy of Sciences 370 05 České Budějovice Czech Republic

Molecular Parasitology and Entomology Unit Laboratory of Malaria and Vector Research NIH NIAID Rockville MD 20852 USA

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