Résumé
The organization of 5′-proximal
c-myb exons in chicken DNA has been established by restriction enzyme mapping and nucleotide sequencing. Hybridization studies performed with cDNA probes revealed that yolk sac and thymic
c-myb RNAs differ in their 5′-termini. A comparison of the genomic
c-myb sequence with that of cDNAs isolated from normal thymic and lymphoma avian cells suggests that different promoter regions are used to initiate
c-myb transcription in hematopoietic cells of different origins.