EXPRESSION OF TROPOMYOSIN GENES DURING THE DEVELOPMENT OF THE RAT CEREBELLUM

Abstract: The expression of the tropomyosin genes in the rat nervous system was examined during the postnatal development of the cerebellum, using human‐specific α‐, β‐, γ‐, and d‐tropomyosin cDNA probes and rat‐specific α‐, β‐, and d‐tropomyosin oligonucleotide probes. The β‐ and γ‐genes do not seem to be expressed in the rat brain. The δ‐tropomyosin gene produces two mRNAs: a major one of 2.4 kb, which is highly concentrated during the first postnatal week and then decreases fourfold in level until the age of 35 days, and a minor one of 2 kb, with the same developmental profile as the 2.4‐kb mRNA. A 3‐kb mRNA is expressed by the α‐tropomyosin gene and is characteristic of the mature rat. The expression of the tropomyosin genes during the development of the rat cerebellum does not seem to be regulated through alternative splicing but rather implies the differential expression of two different isogenes. The multiple isoforms of tropomyosin produced during neuronal differentiation may be intimately involved in the regulation of the organization and function of actin microfilaments. Copyright © 1990, Wiley Blackwell. All rights reserved