title: Mollusc models I. The snail Ilyanassa.
abstract: Ilyanassa obsoleta has been a model system for experimental embryology for over a century. Here we highlight new insight into early cell lineage specification in Ilyanassa. As in all molluscs and other spiralians, stereotyped cleavage patterns establish a homunculus of regional founder cells. Ongoing studies are beginning to dissect mechanisms of asymmetric cell division that specify these cells' fates. This is only part of the story: overlaid on intrinsic cell identities is a graded 'organizer' signal, and emerging evidence suggests wider roles for short-range intercellular signaling. Modern methods, combined with the intrinsic experimental advantages of Ilyanassa, offer attractive opportunities for studying basic developmental cell biology as well as its evolution over a wide range of phylogenetic scales.
authors: Division of Natural Science, Bethel University, McKenzie, TN 38201, United States. Electronic address: morganQgoulding@gmail.com.
authors: Morgan Q
authors: MQ
authors: Goulding
authors: Department of Biology, University of Rochester, Rochester, NY 14627, United States. Electronic address: dlamber2@mail.rochester.edu.
authors: J David
authors: JD
authors: Lambert
mesh_terms: D000818:Animals; D019070:Cell Lineage / Q000235:genetics; D047108:Embryonic Development / Q000235:genetics*; D010802:Phylogeny; D015398:Signal Transduction / Q000235:genetics; D012908:Snails / Q000235:genetics* / Q000254:growth & development