Functional redundancy and/or ongoing pseudogenization among F-box protein genes expressed in Arabidopsis male gametophyte
Functional redundancy and/or ongoing pseudogenization among F-box protein genes expressed in Arabidopsis male gametophyte
复制标题
DOI：
10.1007/s00497-014-0243-1
复制
发表时间：
2014-06-01
影响因子：
3.4
通讯作者：
Bonhomme, Sandrine
中科院分区：
文献类型：
--
作者：
Ikram, Sobia;Durandet, Monique;Bonhomme, Sandrine
F-box蛋白基因家族是植物中最大的基因家族之一，在模式植物拟南芥中预测了近700个基因。F-box蛋白是泛素蛋白酶体系统的关键组成部分，它允许蛋白质的靶向降解。转录组分析表明，这些F-box蛋白基因中有一半在小孢子和/或花粉中表达，即在雄配子发生期间表达。为了评估F-box蛋白基因在这一关键发育阶段中的作用，我们选择了34个在花粉中高表达和特异表达的F-box蛋白基因，并分离出相应的插入突变体。我们通过RT-PCR检测了所选择的每个基因的表达水平，证实了25个基因在花粉中表达，但只有10个基因在34个F-box蛋白基因中特异表达。此外，我们还检测了24个突变株系中F-box蛋白基因的表达水平，发现其中11个为零突变。对这些突变传递给后代的分析表明，这些单一突变都不是配子体致死的。这些未受影响的传输效率表明F-box蛋白基因之间存在泄漏突变或功能冗余。对突变体配子体的细胞学观察证实了上述结果。来自同一亚家族的F-box蛋白基因的突变组合也没有导致传递缺陷，进一步突出了这些F-box蛋白基因中的功能冗余和/或高比例的假基因。
F-box protein genes family is one of the largest gene families in plants, with almost 700 predicted genes in the model plant Arabidopsis. F-box proteins are key components of the ubiquitin proteasome system that allows targeted protein degradation. Transcriptome analyses indicate that half of these F-box protein genes are found expressed in microspore and/or pollen, i.e., during male gametogenesis. To assess the role of F-box protein genes during this crucial developmental step, we selected 34 F-box protein genes recorded as highly and specifically expressed in pollen and isolated corresponding insertion mutants. We checked the expression level of each selected gene by RT-PCR and confirmed pollen expression for 25 genes, but specific expression for only 10 of the 34 F-box protein genes. In addition, we tested the expression level of selected F-box protein genes in 24 mutant lines and showed that 11 of them were null mutants. Transmission analysis of the mutations to the progeny showed that none of the single mutations was gametophytic lethal. These unaffected transmission efficiencies suggested leaky mutations or functional redundancy among F-box protein genes. Cytological observation of the gametophytes in the mutants confirmed these results. Combinations of mutations in F-box protein genes from the same subfamily did not lead to transmission defect either, further highlighting functional redundancy and/or a high proportion of pseudogenes among these F-box protein genes.