Cell lineage specificity of expression of the murine transforming growth factor beta 3 and transforming growth factor beta 1 genes.

Abstract

We have cloned a murine transforming growth factor (TGF) beta 3 complementary (cDNA) from normal tissue by low stringency screening of a testicular cDNA library with a TGF beta 1 probe. The coding domain of this TGF beta 3 cDNA agrees completely with the sequence reported for the TGF beta 3 cDNA isolated from the AKR-2B cell line, but the testicular clone uses a distinct and unusual polyadenylation signal resulting in an altered 3' untranslated domain. Northern blot hybridization analysis of gonadal tissues showed that both TGF beta 3 and TGF beta 1 mRNAs are detectable in the mouse testis and ovary. A detailed analysis of TGF beta 3 and TGF beta 1 gene expression in normal and germ cell-deficient male mice showed that the somatic cell compartment of the mouse testis expresses the usual-sized transcripts for both genes. However, a smaller (1.8-kilobase) TGF beta 1 mRNA is expressed selectively in male germ cells, and expression of this transcript was constitutive throughout the spermatogenic stages examined. This result demonstrates a new pattern of TGF beta 1 gene expression, consistent with cell lineage-specific transcriptional regulation during spermatogenesis.