Section of Plant Biology, University of California, Davis.
Mol Biol Evol. 2013 Oct;30(10):2347-65. doi: 10.1093/molbev/mst132. Epub 2013 Jul 27.
Class IV homeodomain leucine zipper (C4HDZ) genes are plant-specific transcription factors that, based on phenotypes in Arabidopsis thaliana, play an important role in epidermal development. In this study, we sampled all major extant lineages and their closest algal relatives for C4HDZ homologs and phylogenetic analyses result in a gene tree that mirrors land plant evolution with evidence for gene duplications in many lineages, but minimal evidence for gene losses. Our analysis suggests an ancestral C4HDZ gene originated in an algal ancestor of land plants and a single ancestral gene was present in the last common ancestor of land plants. Independent gene duplications are evident within several lineages including mosses, lycophytes, euphyllophytes, seed plants, and, most notably, angiosperms. In recently evolved angiosperm paralogs, we find evidence of pseudogenization via mutations in both coding and regulatory sequences. The increasing complexity of the C4HDZ gene family through the diversification of land plants correlates to increasing complexity in epidermal characters.
IV 类同源域亮氨酸拉链（C4HDZ）基因是植物特异性转录因子，根据拟南芥的表型，它们在表皮发育中起着重要作用。在这项研究中，我们对所有主要现存的谱系及其最接近的藻类近亲进行了 C4HDZ 同源物采样，并进行了系统发育分析，结果得到的基因树反映了陆地植物的进化，有许多谱系中基因复制的证据，但基因丢失的证据很少。我们的分析表明，一个祖先的 C4HDZ 基因起源于陆地植物的藻类祖先，而在陆地植物的最后共同祖先中存在一个单一的祖先基因。独立的基因复制在包括苔藓植物、石松类植物、真蕨类植物、种子植物在内的几个谱系中很明显，尤其是在被子植物中。在最近进化的被子植物旁系同源物中，我们通过编码和调节序列的突变发现了假基因化的证据。C4HDZ 基因家族通过陆地植物的多样化而变得越来越复杂，这与表皮特征的日益复杂化相关。
