A search for c-myb gene regulatory sequences: cloning and restriction analysis of the 18-kb BamHI fragment of chicken chromosomal DNA, containing the 5' part of the c-myb gene.

The 18-kb BamHI fragment of the chicken chromosomal DNA derived from the 5' end of the myb proto-oncogene has been cloned. The 5' part of this clone represented by a 7.2-kb BamHI-EcoRI fragment has been analysed by means of restriction mapping, which revealed the existence of about 2.5 kb of the CpG dinucleotide-rich sequence within this fragment. A short probe prepared from the CpG-rich sequence hybridizes with the 3.6-kb c-myb mRNA. Based on our results and published c-myb cDNA sequence, we conclude that the cloned fragment contains c-myb promoter.