Neural development during embryonic and metamorphic development in
insects
L. P. Tolbert
ARL Division of
Neurobiology, Univ. of Arizona, P.O. Box 210077, Tucson, AZ
85721-0077, USA
Why study the
development of insect nervous systems? Beyond satisfying sheer
curiosity, knowledge of insect neural development holds the hope
of revealing novel and specific paths for biologically sensitive
intervention to protect or to control specific populations of
insects. Furthermore, for developmental biologists, insects offer
a rich source of material. The development of the nervous system
in insects follows different paths, depending on the life history
of the species, yet many of the cellular and molecular mechanisms
underlying neural development appear to be common across disparate
insect species, and even common between insects and mammals (see
Arendt & Nubler-Jung 1999). Individual species variations confer
particular experimental advantages to the investigator using
insects. For all of these reasons, recent years have seen a huge
research effort to understand neural development in insects.
Unable to review all of insect nervous system development in a
one-hour presentation, I will provide a very selective review. I
will focus on the growing understanding of the importance and
nature of cellular interactions in insect neural development. The
nervous systems of certain insects have been excellent systems in
which to study these interactions. Drosophila melanogaster,
a superb organism for genetic studies, has been used to great
advantage to reveal the cellular and molecular bases for
developmental influences in the peripheral and central nervous
systems. Large holometabolous insects, such as the hawkmoth
Manduca sexta, have different advantages; for instance,
developing sensory and central neural structures are readily
accessible throughout a major postembryonic wave of development
(during the metamorphosis of the larva to the adult), when the
animal is large and hardy, readily amenable to surgical
manipulations. Manduca, besides being useful for cellular
studies, also has been especially useful for studies of the
molecular bases of hormone action, a special type of long-range
cellular interaction, in neural development (Levine et al. 1995).
Insect nervous systems develop along widely differing timetables,
depending on the life stages of the species. In this review, I
will provide background on embryonic development and metamorphosis
of the nervous system, but will focus mostly on intercellular
interactions that play key roles no matter what the timetable, no
matter what the extent of postembryonic reorganization, of the
developing nervous system. I will go into most depth on
intercellular interactions during development of the antennal
system in Manduca.
Copyright: The copyrights of
this original work belong to the authors (see right-most box in
title table). This abstract appeared in Session 13 – INSECT
PHISIOLOGY, NEUROSCIENCES, IMMUNITY AND CELL BIOLOGY Symposium
and Poster Session, ABSTRACT BOOK II – XXI-International
Congress of Entomology, Brazil, August 20-26, 2000.
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