An Epigenetic Role for Disrupted Paternal Gene Expression in Postzygotic Seed Abortion in Arabidopsis Interspecific Hybrids  

作　　者：Ryan C. Kirkbride Helen Hong Yu Gyoungju Nah Changqing Zhang Xiaoli Shi Z. Jeffrey Chen 

机构地区：[1]Department of Molecular Biosciences, Center for Computational Biology and Bioinformatics, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA [2]These authors contributed equally to this article. [3]present address: Department of Plant Science, Research Institute of Agriculture and Life Sciences, Seoul National University, Seou1151-921, South Korea [4]present address: Plants for Human Health Institute, North Carolina State University, 600 Laureate Way, Kannapolis, NC 28081, USA [5]present address: Institute of Theoretical Physics, Chinese Academy of Sciences, PO Box 2735, Beijing 100080, China

出　　处：《Molecular Plant》2015年第12期1766-1775,共10页分子植物（英文版）

摘　　要：Interspecific hybrids often increase the levels of heterozygosity and hybrid vigor, but some interspecific hybrid seeds are aborted shortly after fertilization. The mechanism behind this postzygotic seed abortion is poorly understood. Here, we report genome-wide analysis of allelic expression changes in developing siliques and seeds in three F1 interspecific crosses between Arabidopsis thaliana （Col, Ler, or C24） and Arabidopsis arenosa. The majority of maternally expressed genes （MEGs） were shared among all three F1 interspecific crosses, whereas ~90% of 272 paternally expressed genes （PEGs） were found only in one or two F1 crosses, suggesting a role for disrupted paternal gene expression in seed abortion that varies in different crosses. Consistent with this notion, 12 PEGs in the infertile interspecific hybrids matched MEGs in fertile intraspecific hybrids. This disruption of PEGs in the interspecific hybrids was consistent with the upregulation of the genes in the paternal-excess interploidy cross （2X6） between a diploid mother and a hexaploid father, leading to the seed abortion. Moreover, a subset of PEGs in the interspecific crosses were also upregulated in the intraspecific hybrid metlXWT or meaXWT, in which the mutant of MET1 （DNA METHYL TRANSFERASE1） or MEDEA, a Polycomb Repressive Complex2 gene, was used as the maternal parent. These data suggest that maternal epigenetic factors and paternal gene expression play important roles in the postzygotic seed abortion in interspecific hybrids or neo-allopolyploids.Interspecific hybrids often increase the levels of heterozygosity and hybrid vigor, but some interspecific hybrid seeds are aborted shortly after fertilization. The mechanism behind this postzygotic seed abortion is poorly understood. Here, we report genome-wide analysis of allelic expression changes in developing siliques and seeds in three F1 interspecific crosses between Arabidopsis thaliana （Col, Ler, or C24） and Arabidopsis arenosa. The majority of maternally expressed genes （MEGs） were shared among all three F1 interspecific crosses, whereas ~90% of 272 paternally expressed genes （PEGs） were found only in one or two F1 crosses, suggesting a role for disrupted paternal gene expression in seed abortion that varies in different crosses. Consistent with this notion, 12 PEGs in the infertile interspecific hybrids matched MEGs in fertile intraspecific hybrids. This disruption of PEGs in the interspecific hybrids was consistent with the upregulation of the genes in the paternal-excess interploidy cross （2X6） between a diploid mother and a hexaploid father, leading to the seed abortion. Moreover, a subset of PEGs in the interspecific crosses were also upregulated in the intraspecific hybrid metlXWT or meaXWT, in which the mutant of MET1 （DNA METHYL TRANSFERASE1） or MEDEA, a Polycomb Repressive Complex2 gene, was used as the maternal parent. These data suggest that maternal epigenetic factors and paternal gene expression play important roles in the postzygotic seed abortion in interspecific hybrids or neo-allopolyploids.

关 键 词：epigenetics IMPRINTING paternal gene expression POLYPLOIDY hybrid incompatibility seeddevelopment 

分 类 号：U469.11[机械工程—车辆工程] X53[交通运输工程—载运工具运用工程]