Wax lipid secretion and ultrastructural development in the egg-waxing (Gene's) organ in ixodid ticks

Gene's organ, the egg-waxing organ of ticks, performs an essential function in females by coating the eggs with a waterproofing layer during oviposition, which prevents desiccation of the embryo, ensuring its viability. The organ is a target for control agents and a potential site of virus replication involving trans-oval transmission of arboviruses. The organ is a complex dermal gland, developed to an elaborate degree. The external appendage, the horns, is an evertable balloon-like cuticular sac which manipulates the eggs and coats them in wax. Wax passes through pores in the cuticle from the internal, sub-cuticular lumen. Gene's organ develops in synchrony with oogenesis and oviposition. This paper describes the development of the gland cells and formation of the intra-cuticular lumen and its ultrastructure during engorgement and oviposition in ixodid ticks. The structural basis for wax secretion in Gene's organ is also described.