A 5.1 kilobase-pair segment of rabbit chromosomal beta-globin DNA was joined to pJDB219, a plasmid consisting of pMB9, the 2-mu yeast plasmid and the yeast leu-2 gene. Saccharomyces cerevisiae transformed with the globin DNA-containing hybrid produced beta-globin-specific RNA. As compared to mature beta-globin mRNA, these transcripts lacked 20-40 nucleotides from the 5' end, contained all of the small intron and extended to about the middle of the large intron. Thus, no splicing of the primary beta-globin transcript could be detected in the yeast cells.