Abstract：
The evolution of major taxa is often associated with the emergence of new gene families. In all multicellular animals except sponges and comb jellies, the genomes contain Hox genes, which are crucial regulators of development. The canonical function of Hox genes involves colinear patterning of body parts in bilateral animals. This general function is implemented through complex, precisely coordinated mechanisms, not all of which are evolutionarily conserved and fully understood. We suggest that the emergence of this regulatory complexity was preceded by a stage of cooperation between more ancient morphogenetic programs or their individual elements. Footprints of these programs may be present in modern animals to execute non-canonical Hox functions. Non-canonical functions of Hox genes are involved in maintaining terminal nerve cell specificity, autophagy, oogenesis, pre-gastrulation embryogenesis, vertical signaling, and a number of general biological processes. These functions are realized by the basic properties of homeodomain protein and could have triggered the evolution of ParaHoxozoa and Nephrozoa subsequently. Some of these non-canonical Hox functions are discussed in our review.
摘要：
主要分类群的进化通常与新基因家族的出现有关。在所有多细胞动物中，除了海绵和梳子果冻，基因组中含有Hox基因,是发展的关键监管者。Hox基因的规范功能涉及双侧动物身体部位的共线模式。这个通用功能是通过复杂的，精确协调的机制，并非所有这些都是进化上保守和充分理解的。我们建议，这种监管复杂性的出现是在更古老的形态发生程序或其各个元素之间进行合作的阶段之前。这些程序的足迹可能存在于现代动物中以执行非规范的Hox函数。Hox基因的非经典功能参与维持终末神经细胞特异性，自噬,卵子发生，原肠胚形成前胚胎发生，垂直信号，和一些一般的生物过程。这些功能是通过同源域蛋白的基本特性实现的，并且可能随后触发了副Hoxozoa和肾动物的进化。在我们的评论中讨论了其中一些非规范的Hox函数。
