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We report the molecular cloning of cDNA copies of DBA/2 mouse submaxillary gland (SMG) renin mRNA, which were used to probe Southern transfers of mouse genomic DNA. The results suggested either that there is a single renin gene containing a large intron in that part of the gene corresponding to the probe, or that there are two distinct renin genes. We have shown that the latter is the case by cloning and isolating two similar but distinct renin genes from DBA/2 mouse DNA. Restriction maps of the regions containing the two renin genes are presented, together with nucleotide sequence data locating a complete exon coding for amino acids 268‐315 of mouse SMG renin.

Two cDNA libraries were constructed, using respectively the 12S and the 16S sucrose gradient fractions of polysomal poly (A)+ RNA from mouse C243 cells induced with Newcastle disease virus. Screening of a part of both libraries by mRNA selection hybridization assays revealed the presence of two plasmids hybridizing to an mRNA, whose translation product was characterized as mouse IFN-beta. Blot analysis of RNA indicated that mRNA hybridizing to the DNA from both plasmids could be detected in induced but not in uninduced C243 cells. The two cDNA inserts did not cross hybridize and had distinct restriction maps. Sequencing revealed that both inserts represented the end of the coding region and the entire 3' non coding region of two district mRNAs. Although different, the putative 39 AA and 65 AA carboxy termini of both Mu IFN-beta s display some homology to human IFN-beta 1. Thus there are at least two different murine IFN-beta genes.

cDNA libraries have been constructed from mRNAs isolated from mature male DBA/2 mouse submaxillary glands. Several recombinant plasmids have been assigned to particular mRNA species and their in vitro translation products by HART and hybrid selection. Clones containing copies of two abundant mRNA species that showed no sexual dimorphism were selected for detailed characterisation. Nucleotide sequences determined from one series of clones define an 850 nucleotide mRNA encoding a polypeptide of 16.5 kd having an N-terminal signal sequence, an acidic core and four glycosylation sites. A second family of clones correspond to an mRNA of 800 nucleotides, the sequence of which can be interpreted as coding for an intracellular protein of 14.7 kd. Computer searches of protein and nucleic acid sequences have not revealed the identity of either of these submaxillary gland products.

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