Heterologous CpG island becomes extensively methylated in the genome of transgenic mice.
It is demonstrated that a heterologous (chicken) CpG island containing five Sp1 canonical recognition sequences becomes highly methylated in the genome of transgenic mice bearing one or several copies of the transgene. Similar levels of methylation of the chicken CpG island were observed in different tissues of transgenic mice except the brain where the level of methylation of this chicken CpG-rich fragment was significantly lower than in other tissues. Analysis of susceptibility of the "transgenic" CpG island to Hpa II and Msp I restriction nucleases revealed an unusual methylation pattern interfering with the action of both of these enzymes. A conclusion has been drawn that heterologous CpG island per se does not contain all necessary signals permitting to maintain its own non-methylated status in the genome of transgenic animals.
Ioudinkova
Elena
E
Laboratory of Structural and Functional Organization of Chromosomes, Institute of Gene Biology RAS, 119334 Moscow, Russia.
Verbovaia
Lilia
L
Kadulin
Sergey
S
Goldman
Igor
I
Razin
Sergey V
SV
D000818:Animals; D002645:Chickens / Q000235:genetics*; D018899:CpG Islands; D019175:DNA Methylation; D016678:Genome; D005914:Globins / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics
D005914:Globins