Evolução dos genes Hox anteriores e a diversidade dos arquétipos metazoários

Abstract

Metazoan phylogenies based on genes involved with specification of body plans provides a powerful alternative to those based on morphological traits and/or classical molecular markers. They give clues not only on animal evolutionary history, but also on associated changes in their molecular architecture. Here, we use publicly available sequences of Hox gene clusters involved with anterior region patterning (Hox1-Hox4), to reconstruct the evolutionary history of metazoans. We show that information harbored by these genes reflects the evolution and diversification of most animal archetypes. Moreover, our findings reveal that evolution of Hox genes (and clusters) as a multigene family is consistent to a birth-and-death model constrained by development, where there is a trade-off between a relatively fast gene turnover and their central developmental roles. Our findings provide both a strongly supported broad phylogeny of metazoans and an evolutionary model to explain the evolution of Hox genes – a multigene family that is fundamental to animal development and which is likely to have influenced the diversification of animal archetypes.