Cellular carbon accumulation systems are a fundamental prerequisite for biomineralization to stabilize pH and to supply inorganic carbon for CaCO3 precipitation under changing environmental conditions.
Expression of two highly regulated subfamilies of the complex multigene family encoding IL-17 cytokines in the purple sea urchin are sequentially activated in a larval gut-associated inflammation model and modulate downstream gene expression in the gut epithelium.
Eph receptor signaling commonly excludes migrating embryonic cells from regions of high ligand density; however, in sea urchin embryos pigmented immunocytes are attracted to regions expressing high levels of Ephrin.
A gene duplication event has permitted the functional specialization of a homeodomain transcription factor through changes in exon-intron organization and these changes have supported the evolution of a major, phylum-level morphological novelty.
A conserved alternative splicing program is specific to planarian stem cells and is controlled by the highly conserved splicing factors CELF and MBNL; therefore, this mode of regulating stem cells is likely ancestral to all animals.