ALLELE-SPECIFIC PARENTAL IMPRINTING OF DZR1, A POSTTRANSCRIPTIONAL REGULATOR OF ZEIN ACCUMULATION

Parental imprinting describes the phenomenon of unequivalent gene func tion based on transmission from the female or male parent. We have dis covered parental imprinting of an allele of the dzr1 locus that posttr anscriptionally regulates the accumulation of 10-kDa zein in the maize endosperm. The imprinted allele of MO17 inbred origin, dzr1+MO17, con ditions low accumulation of the 10-kDa zein and is dominant when trans mitted through the female but recessive when transmitted through the m ale. Analyzing endosperms with equal parental contributions of dzr1+MO 17 ruled out the possibility that the unequivalent phenotype of dzr1+M O17 was due to parental dosage imbalance in the triploid endosperm. Se cond-generation studies show that the dominant or recessive phenotype of dzr1+MO17 is determined at every generation based on immediate pare ntal origin with no grandparental effect.