Sensory Cell Proliferation within the Olfactory Epithelium of Developing Adult Manduca sexta (Lepidoptera)
Figure 1
Olfactory Development, Sensillum Anatomy and Tissue Dissection.
1A. Overview of animal and antennal development in M. sexta. Time line represents days of development. W = onset of wandering behavior; P = pupal ecdysis; A = adult ecdysis. Asterisk under Pupa Day 2 marks time of developmental arrest for animals entering diapause. Asterisks under Pupa Days 9,10 mark times of specific apoptotic activity in olfactory epithelium (death of “t2 cells”; ref 6). See text for other details. 1B. Schematic of an olfactory sensillum. Olfactory neurons associate with three support cells that serve several functions including formation of the sensillum cuticle early in development and the secretion of perireceptor proteins (e.g. OBPs, ODEs) late in development. Distinct sensillum types differ in cuticle morphology, number of neurons and the branched state of the neuronal dendrites, as well as the combinatorial expression of sets of olfactory genes [ref 20], [64], [65]. 1C. Tissue dissection. A scalpel incision was made through the pupal cuticle along the inside perimeter of the developing antenna. For pre-apolysis animals, the underlying presumptive sensory epithelium was attached to the cuticle; cuticle with epithelium attached was processed for histological and tissue culture studies. For post-apolysis animals, removal of the pupal cuticle allows access and removal of the developing antennal tissue within.