Extensive maternal DNA hypomethylation in the endosperm of Zea mays.
A PCR-based genomic scan has been undertaken to estimate the extent and ratio of maternally versus paternally methylated DNA regions in endosperm, embryo, and leaf of Zea mays (maize). Analysis of several inbred lines and their reciprocal crosses identified a large number of conserved, differentially methylated DNA regions (DMRs) that were specific to the endosperm. DMRs were hypomethylated at specific methylation-sensitive restriction sites upon maternal transmission, whereas upon paternal transmission, the methylation levels were similar to those observed in embryo and leaf. Maternal hypomethylation was extensive and offers a likely explanation for the 13% reduction in methyl-cytosine content of the endosperm compared with leaf tissue. DMRs showed identity to expressed genic regions, were observed early after fertilization, and maintained at a later stage of endosperm development. The implications of extensive maternal hypomethylation with respect to endosperm development and epigenetic reprogramming will be discussed.
Lauria
Massimiliano
M
Plant Biochemistry Laboratory, Department of Plant Biology, Royal Veterinary and Agricultural University, DK-1871 Frederiksberg C, Denmark.
Rupe
Mary
M
Guo
Mei
M
Kranz
Erhard
E
Pirona
Raul
R
Viotti
Angelo
A
Lund
Gertrud
G
D001665:Binding Sites / Q000235:genetics; D015139:Blotting, Southern; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D019175:DNA Methylation; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019003:Deoxyribonuclease HpaII / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D012150:Polymorphism, Restriction Fragment Length; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D003313:Zea mays / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D018744:DNA, Plant; D019003:Deoxyribonuclease HpaII