Journal of Neuroscience, Vol 8, 296-307, Copyright © 1988 by Society for Neuroscience
Monoclonal antibodies reveal cell-type-specific antigens in the sexually dimorphic olfactory system of Manduca sexta. I. Generation of monoclonal antibodies and partial characterization of the antigens
A Hishinuma, S Hockfield, R McKay and JG Hildebrand
Department of Biological Sciences, Columbia University, New York, New York 10027.
The olfactory system of the moth Manduca sexta is sexually dimorphic. Male
moths possess a male-specific olfactory "subsystem," comprising olfactory
receptor cells (ORCs) and CNS neurons and synaptic areas associated with
the detection of female sex pheromones, in addition to elements common to
males and females. In order to explore the molecular differences between
cells that subserve the sexual dimorphism and odor- specificity of
components of the olfactory system, we generated monoclonal antibodies
(Mabs) against tissue of the olfactory system of the moth. In 2 fusions, we
screened 1105 hybridoma lines and obtained 272 lines that secreted
antibodies against Manduca nervous tissue, as assayed immunocytochemically
on sections of the primary olfactory center (the antennal lobe) in the
brain of Manduca. We describe here 3 classes of Mabs exemplifying the
several cell-type-specific antibodies obtained through the screening
procedure. Seven hybridoma lines secrete antibodies that specifically
recognize cell bodies, axons, and initial segments of dendrites of many or
all ORCs of both males and females (classified as olfactory-specific
antibodies, OSAs). Electron- microscopic studies of 2 of the Mabs in this
class showed that they recognize antigens associated with the cell membrane
and that the immunoreactive ORC axons are bundled together in fascicles in
the antennal nerve. On immunoblots, one of the OSA Mabs recognizes 3
distinct protein bands of apparent Mrs 42,000, 59,000, and 66,000 Da. When
tissue samples enriched in either receptor cell bodies, dendrites, and
initial segments of axons or in distal segments of axons and their
terminals and synapses were extracted separately, different patterns of
bands were detected--42,000 and 59,000 Da bands from cell bodies and
initial segments of axons and dendrites, and 42,000 and 66,000 Da bands
from distal segments of axons and their terminals--suggesting that the
59,000 Da protein is modified to the 66,000 Da protein during axonal
transport. The second Mab we describe here, the male olfactory-specific
antibody (MOSA), selectively recognizes the sexually dimorphic ORCs that
are present only in males. The antigen recognized by this antibody is found
in cell bodies, dendrites, axons, and axon terminals. By
electron-microscopic immunocytochemistry, the MOSA immunoreactivity is
found in the cytoplasm and appears not to be associated with particular
subcellular organelles. This antibody demonstrates that male-specific ORCs
are molecularly distinct from other types of ORCs.(ABSTRACT TRUNCATED AT
400 WORDS)