Springer Nathan M, Danilevskaya Olga N, Hermon Pedro, Helentjaris Tim G, Phillips Ronald L, Kaeppler Heidi F, Kaeppler Shawn M
Department of Agronomy, University of Wisconsin, Madison, WI 53706, USA.
Plant Physiol. 2002 Apr;128(4):1332-45. doi: 10.1104/pp.010742.
Polycomb group (PcG) proteins play an important role in developmental and epigenetic regulation of gene expression in fruit fly (Drosophila melanogaster) and mammals. Recent evidence has shown that Arabidopsis homologs of PcG proteins are also important for the regulation of plant development. The objective of this study was to characterize the PcG homologs in maize (Zea mays). The 11 cloned PcG proteins from fruit fly and the Enhancer of zeste [E(z)], extra sex combs (esc), and Enhancer of Polycomb [E(Pc)] homologs from Arabidopsis were used as queries to perform TBLASTN searches against the public maize expressed sequence tag database and the Pioneer Hi-Bred database. Maize homologs were found for E(z), esc, and E(Pc), but not for Polycomb, pleiohomeotic, Posterior sex combs, Polycomblike, Additional sex combs, Sex combs on midleg, polyhometoic, or multi sex combs. Transcripts of the three maize Enhancer of zeste-like genes, Mez1, Mez2, and Mez3, were detected in all tissues tested, and the Mez2 transcript is alternatively spliced in a tissue-dependent pattern. Zea mays fertilization independent endosperm1 (ZmFie1) expression was limited to developing embryos and endosperms, whereas ZmFie2 expression was found throughout plant development. The conservation of E(z) and esc homologs across kingdoms indicates that these genes likely play a conserved role in repressing gene expression.
多梳蛋白组（PcG）蛋白在果蝇（黑腹果蝇）和哺乳动物的基因表达的发育调控和表观遗传调控中发挥着重要作用。最近的证据表明，PcG蛋白在拟南芥中的同源物对植物发育的调控也很重要。本研究的目的是鉴定玉米（玉米）中的PcG同源物。以从果蝇中克隆的11种PcG蛋白以及来自拟南芥的zeste增强子[E(z)]、额外性梳（esc）和多梳增强子[E(Pc)]同源物作为查询序列，对公共玉米表达序列标签数据库和先锋良种数据库进行TBLASTN搜索。发现了E(z)、esc和E(Pc)的玉米同源物，但未发现多梳、多同源异型、后性梳、类多梳、额外性梳、中腿性梳、多同源异型或多性梳的同源物。在所有测试组织中均检测到了三个玉米类zeste增强子基因Mez1、Mez2和Mez3的转录本，并且Mez2转录本以组织依赖的模式进行可变剪接。玉米受精独立胚乳1（ZmFie1）的表达仅限于发育中的胚胎和胚乳，而ZmFie2的表达在植物发育过程中均有发现。跨物种的E(z)和esc同源物的保守性表明这些基因可能在抑制基因表达中发挥保守作用。
