The evolution of nervous systems in animals has always fascinated biologists, and thus
multiple evolutionary scenarios have been proposed to explain the appearance of neurons …

The so-called extra-embryonic tissues are important for embryonic development in many
animals, although they are not considered to be part of the germ band or the embryo proper …

Twenty years after its proposal, the monophyly of molting protostomes—Ecdysozoa—is a
well-corroborated hypothesis, but the interrelationships of its major subclades are more …

For more than a century, the origin and evolution of the arthropod head and brain have
eluded a unifying rationale reconciling divergent morphologies and phylogenetic …

The radula is the central foraging organ and apomorphy of the Mollusca. However, in
contrast to other innovations, including the mollusk shell, genetic underpinnings of radula …

Paired box genes are conserved across animals and encode transcription factors playing
key roles in development, especially neurogenesis. Pax6 is a chief example for functional …

The paired box (PAX) family of transcription/developmental genes plays a key role in
numerous stages of embryonic development, as well as in adult organogenesis. There is …

Abstract Onychophorans, or “velvet worms”(Fig. 4.1), are multi-legged, terrestrial
invertebrates that inhabit decaying logs, soil, and leaf litter of tropical and temperate forests …

The diverse and complex developmental mechanisms of segmentation have been more
thoroughly studied in arthropods, vertebrates and annelids—distantly related animals …

Background One set of the developmentally important Doublesex and Male-abnormal-3
Related Transcription factors (Dmrt) is subject of intense research, because of their role in …