Methylation of hen erythrocyte DNA.

We have analysed the 5-methylcytosine content of hen erythrocyte DNA and found it to be lower than that of DNA from other chick tissues analysed. Erythrocyte DNA is also a better substrate for DNA methylase having a five-fold lower Km than DNA from white blood cells. This is probably because it contains a large number of hemimethylated sites. Thus the inverse correlation between methylation and gene expression does not apply to the chick red blood cell.