Brain-specific tropomyosins TMBr-1 and TMBr-3 have distinct patterns of expression during development and in adult brain.
In this study we report on the developmental and regional expression of two brain-specific isoforms of tropomyosin, TMBr-1 and TMBr-3, that are generated from the rat alpha-tropomyosin gene via the use of alternative promoters and alternative RNA splicing. Western blot analysis using an exon-specific peptide polyclonal antibody revealed that the two isoforms are differentially expressed in development with TMBr-3 appearing in the embryonic brain at 16 days of gestation, followed by the expression of TMBr-1 at 20 days after birth. TMBr-3 was detected in all brain regions examined, whereas TMBr-1 was detected predominantly in brain areas that derived from the prosencephalon. Immunocytochemical studies on mixed primary cultures made from rat embryonic midbrain indicate that expression of the brain-specific epitope is restricted to neurons. The developmental pattern and neuronal localization of these forms of tropomyosin suggest that these isoforms have a specialized role in the development and plasticity of the nervous system.
Stamm
S
S
Cold Spring Harbor Laboratory, NY 11724.
Casper
D
D
Lees-Miller
J P
JP
Helfman
D M
DM
D000375:Aging / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D001483:Base Sequence; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D017931:DNA Primers; D005314:Embryonic and Fetal Development; D000939:Epitopes / Q000032:analysis; D005091:Exons; D005786:Gene Expression Regulation / Q000502:physiology*; D005865:Gestational Age; D015151:Immunoblotting; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D009928:Organ Specificity; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D016133:Polymerase Chain Reaction; D051381:Rats; D017207:Rats, Sprague-Dawley; D014335:Tropomyosin / Q000032:analysis / Q000096:biosynthesis*
D000906:Antibodies; D017931:DNA Primers; D000939:Epitopes; D010455:Peptides; D014335:Tropomyosin