C. Steiner et Ta. Keil, MORPHOGENESIS OF THE ANTENNA OF THE MALE SILKMOTH, ANTHERAEA-POLYPHEMUS .6. EXPERIMENTAL DISTURBANCE OF ANTENNAL BRANCH FORMATION, Tissue & cell, 27(3), 1995, pp. 289-297
In the male silkmoth Antheraea polyphemus, the formation of the side b
ranches of the quadripectinate antennal flagellum was disturbed by an
experimental manipulation. Normally the side branches develop in the p
upa via deep incisions which proceed from the periphery towards the ce
nterline of the leaf-shaped antennal anlage. Local removal of the uppe
rmost, pigmented cuticular layers of the pupal antennal pocket ('cutic
ular window') led to a local standstill of branch formation in the man
ipulated region of the pocket, most probably caused by increased evapo
ration of water through the remaining layers of meso- and endocuticle.
These parts of the antenna retained an unbranched, plate-like shape.
This early morphogenetic stage was conserved by the secretion of anten
nal cuticle. Besides cuticle formation, development of sensilla is not
impeded by the manipulation. In the plate-shaped regions, the initial
pattern formed by the sensilla in the antennal epidermis is preserved
, because they maturate at their birthplaces. In the individual segmen
ts, the pattern of sensilla shows a mirror-like symmetry with respect
to the segmental midline. From the edge to the midline, we found large
s. trichodea, followed by small s. trichodea, s. basiconica, and s. c
oeloconica on the dorsal side whereas on the ventral side, there are o
nly large s. trichodea and s. campaniformia. We conclude that the deve
lopment of the featherlike antennal shape on the one hand and the deve
lopment of sensilla and cuticle on the other hand are independent proc
esses.