A test for a metastable epigenetic component of heterosis using haploid induction in maize
A test for a metastable epigenetic component of heterosis using haploid induction in maize
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DOI：
10.1007/s00122-003-1521-8
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发表时间：
2004-04-01
影响因子：
5.4
通讯作者：
Birchler, JA
中科院分区：
文献类型：
--
作者：
Auger, DL;Ream, TS;Birchler, JA
我们进行了一项测试，以检测是否有一个可遗传的表观遗传的组成部分，杂种优势和/或近交衰退。这项工作的动力是一个经典的研究纯合性的玉米红色（r1）基因座的表达的影响。研究表明，在几代中保持R1斑驳等位基因的纯合状态会导致其父系印记表达的逐渐减少。这种效应被R1/R1等位基因杂合性逆转。如果这种行为是许多调控基因的特征，那么这种现象可能有助于近交衰退和杂种优势。为了检验这个问题，Mo 17和B73的近交系以及两个杂交产生的杂种与原种6杂交以产生四类母本单倍体。对成熟的单倍体植株进行了几个数量性状的测定。如果近交衰退是由积累的遗传效应引起的，而这种遗传效应又被杂交状态所逆转，那么人们会期望来自杂交种的单倍体比来自近交系的单倍体表现得更好。杂交衍生的单倍体没有表现出比近交衍生的单倍体更高的平均性能。这些数据不能支持近交衰退和杂种优势具有亚稳定表观遗传成分的假设。
We conducted a test to detect if there is a heritable epigenetic component to hybrid vigor and/or inbreeding depression. The impetus for this work was a classical study of the effect of homozygosis on the expression of the maize red color (r1) locus. It had been shown that maintaining R1 mottling alleles in the homozygous state over several generations produces a progressive decrease of their paternally imprinted expression. This effect is reversed by R1/r1 allele heterozygosity. If this behavior were characteristic of many regulatory genes, then such a phenomenon could contribute to inbreeding depression and heterosis. To examine this question, inbreds of Mo17 and B73 and the two reciprocally produced hybrids were crossed by Stock 6 to generate four classes of maternal haploids. The mature haploid plants were measured for several quantitative traits. If inbreeding depression results from an accumulating heritable effect that is reversed by the hybrid state, one would expect the haploids derived from the hybrids to perform better than those derived from the inbred lines. The hybrid-derived haploids did not exhibit greater average performance than the inbred-derived haploids. These data fail to support the hypothesis that inbreeding depression and heterosis have a metastable epigenetic component.