these cellular sequences ( c-erb ) were transcribed at low levels ( 1 to 2 rna copies per cell ) in chicken and quail fibroblasts , in which the two alleged domains of aev-specific sequences corresponding to the 75,000- and 40,000-molecular-weight proteins seemed to be conserved phylogenetically and transcribed at similar low rates .
C0007634
cell
C0016030
fibroblasts