Volume 17, Number 9,
Issue of May 1, 1997
pp. 3148-3156
Copyright ©1997 Society for Neuroscience
Maternally Derived Immunoglobulin Light Chain Is Present in the
Fetal Mammalian CNS
Received Feb. 10, 1997; accepted Feb. 19, 1997.
Joshua A. Weiner1 and
Jerold Chun2
1 Neurosciences Graduate Program and
2 Neurosciences and Biomedical Sciences Graduate Programs,
Department of Pharmacology, School of Medicine, University of
California, San Diego, La Jolla, California 92093-0636
Toward identifying molecules involved in cell-cell interactions
during cerebral cortical development, we have investigated the nature
of immunoglobulin-like immunoreactivity (Ig-ir) in the murine cortex.
Immunohistochemistry using several antisera recognizing IgG revealed
intense immunoreactivity in the subplate and marginal zone of embryonic
day 16 cortex, as well as in the hindbrain and spinal cord,
particularly within ventral fiber tracts. In three independently
derived mouse strains lacking the recombination activating genes RAG-1
or RAG-2, which are essential for Ig production, Ig-ir was absent from
the fetal CNS. Western blot analyses of wild-type brains from embryonic
day 12 through birth identified a 25 kDa protein that co-migrated with
Ig light chain and was absent from RAG-1 or RAG-2
/
brain samples.
This result could be replicated with an antiserum specific for Ig
light chain, but not with antisera specific for Ig
or µ heavy
chain. No Ig-ir was detected in the brains of RAG-1 +/
embryos
carried by a
/
female, suggesting a maternal source of the
immunoreactive molecule. In confirmation of this, Ig-ir could be
partially reproduced by intraperitoneal injection of pregnant RAG-1
/
females with normal mouse serum. We conclude that maternally
derived Ig light chain is present in the fetal murine CNS. This may
represent a novel maternal contribution to fetal neural development and
implicates Ig molecules as potential mediators of cortical
developmental events.
Key words:
subplate;
cortex;
immunoglobulin;
RAG;
development;
light
chain