The Journal of Neuroscience, September 1, 1998, 18(17):6928-6938
Retroviral Transfer of Antisense Integrin
6 or
8 Sequences
Results in Laminar Redistribution or Clonal Cell Death in Developing
Brain
Zhiqiang
Zhang and
Deni S.
Galileo
Department of Cellular Biology and Anatomy, Medical College of
Georgia, Augusta, Georgia 30912-2000
To assess the roles of two integrin
subunits (
6 and
8) in
the developing chicken optic tectum, progenitors were infected with
retroviral vectors that contained the marker gene lacZ plus antisense
sequences from either the
6 or
8 integrin subunit cDNAs. On
embryonic day 3 (E3), the vector was injected into tectal ventricles of
chicken embryos. On E6, E7.5, E9, or later, chicken embryos were
killed, and optic tecta were dissected and processed for histochemical
detection of lacZ-positive cells. The antisense-bearing cell clones
(descendants of a single infected progenitor) were analyzed for
proliferation and migration patterns and were compared with lacZ-only
vector-infected control clones. At E6, both
6 and
8 integrin
antisense-containing cell clones were similar to controls. At E7.5,
integrin
8 antisense-containing clones exhibited a cell number
reduction in upper laminae (intermediate zone and tectal plate), and at
E9, they exhibited a reduction in the ventricular zone as well.
Integrin
6 antisense-containing cell clones exhibited no difference
in total cell number at E9 but had a net laminar redistribution of more
cells in the ventricular zone and less cells in the tectal plate. Our
data show that different integrins play different roles during brain
development:
6 integrin is essential for migration of tectal cells
into specific laminae, and
8 integrin is essential for the survival
of optic tectum cells. Also
8 integrin-substrate interactions may
suppress early programmed cell death in premigratory and migratory
neuroblasts.
Key words:
integrin; antisense; neuronal migration; apoptosis; retroviral vector; chicken embryo
Copyright © 1998 Society for Neuroscience 0270-6474/98/18176928-11$05.00/0