Expression of c-myc in canine mammary tumours

The expression of the protooncogene c-myc was examined in twelve canine mammary tumours of different histological type. Only in one tumour--a poorly differentiated carcinoma--was the amount of RNA that hybridized with our cDNA probe for the myc gene significantly increased. Restriction fragment length analysis of genomic DNA from this tumour did not reveal any amplification or other rearrangements in this gene locus.