The discovery of millions of PIWI-interacting RNAs revealed a fascinating and unanticipated
dimension of biology. The PIWI–piRNA pathway has been commonly perceived as germline …

The textbook view of cell division terminates with the final separation of the two daughter
cells in the process called abscission. However, in contrast to this classical view, a variety of …

Planarians are members of the Platyhelminthes (flatworms). These animals have evolved a
remarkable stem cell system. A single pluripotent adult stem cell type (“neoblast”) gives rise …

Animal evolution is often presented as a march toward complexity, with different living
animal groups each representing grades of organization that arose through the progressive …

The topipotency of the germline is the full manifestation of the pluri-and multipotency of
embryonic and adult stem cells, thus the germline and stem cells must share common …

In most animals, pluripotency is irreversibly lost post gastrulation. By this stage, all
embryonic cells have already committed either to one of the somatic lineages (ectoderm …

The origin of animals, one of the major transitions in evolution, remains mysterious. Many
key aspects of animal evolution can be reconstructed by comparing living species within a …

Whole-body regeneration is widespread in the Metazoa, yet little is known about how
underlying molecular mechanisms compare across phyla. Acoels are an enigmatic phylum …

In animals, stem cell populations of varying potency facilitate regeneration and tissue
homeostasis. Notably, germline stem cells in both vertebrates and invertebrates express …

PIWI proteins and their bound PIWI-interacting RNAs (piRNAs) are found in animal
germlines and are essential for fertility, but their functions outside of the gonad are not well …