Expression of novel alternatively spliced isoforms of the oct-1 transcription factor

Analysis of the alternatively spliced isoforms of the human and mouse oct-1 genes, combined with their exon-intron structure, show a high level of evo lutionary conservation between these two species; The differential expressi on of several oct-1 isoforms was examined by reverse transcription-polymera se chain reaction performed on the 3' region of the murine oct-1 cDNA. Vari ations in the relative levels and patterns of expression of the isoforms we re found among different tissues. Three novel isoforms originating from the 3'-distal region of oct-1, were isolated and sequenced: Two were derived f rom testis, and one from myeloma cells. Splicing out of different exons as revealed in the structure of these isoforms results in reading frameshifts that presumably lead to the expression of shortened Oct-1 proteins, with di stinct C-terminal tails. Altogether, six out of the eight known murine oct- 1 isoforms may have distinct C-termini, implying: that these multiple tails have different functional roles in cellular differentiation and physiology . (C) 1999 Elsevier Science B.V. All rights reserved.