A primary object of this invention is to provide a method which will enable to
coexpress simultaneously two (or more) desired genes in plant, animal or yeast
cells, in transgenic plants and animals, or in vitro, in plant cell-derived or
animal cell-derived translation systems. This objection is to be accomplished by
utilizing sequence elements derived from RNAs of a tobamovirus upstream of MP gene
or CP gene termed here as IRESMP and IRESCP , respectively.
The method of this invention involves the construction of a recombinant nucleic
acid sequence which comprises a specific transcriptional promoter, a first gene
expressible in eukaryotic cells linked to said transcriptional promoter, IRESMP
or IRESCP located 3 to the first gene and a second gene
expressible in eukaryotic cells, located 3 to IRES sequence such that the
second gene is placed under the transcriptional control of IRES sequence originated
from tobamovirus genome. The primary chimeric RNA transcript in positive sense
polarity is produced by the transformed cells from the said promoter. The expression
of the first gene occurs by direct translation whereas the translation of the 5-distal
gene(s) of bicistronic (or polycistronic) mRNA will be promoted by IRESMP
or IRESCP.
