Whole-organ cell shape analysis reveals the developmental basis of ascidian notochord taper.

TitleWhole-organ cell shape analysis reveals the developmental basis of ascidian notochord taper.
Publication TypeJournal Article
Year of Publication2013
AuthorsVeeman MT, Smith WC
JournalDev Biol
Date Published2013 Jan 15
KeywordsAnimals, Cell Polarity, Cell Shape, Cell Size, Embryo, Nonmammalian, Larva, Models, Biological, Notochord, Organ Specificity, Tail, Time Factors, Urochordata

Here we use in toto imaging together with computational segmentation and analysis methods to quantify the shape of every cell at multiple stages in the development of a simple organ: the notochord of the ascidian Ciona savignyi. We find that cell shape in the intercalated notochord depends strongly on anterior-posterior (AP) position, with cells in the middle of the notochord consistently wider than cells at the anterior or posterior. This morphological feature of having a tapered notochord is present in many chordates. We find that ascidian notochord taper involves three main mechanisms: Planar Cell Polarity (PCP) pathway-independent sibling cell volume asymmetries that precede notochord cell intercalation; the developmental timing of intercalation, which proceeds from the anterior and posterior towards the middle; and the differential rates of notochord cell narrowing after intercalation. A quantitative model shows how the morphology of an entire developing organ can be controlled by this small set of cellular mechanisms.

Alternate JournalDev. Biol.
PubMed ID23165294
PubMed Central IDPMC3534886
Grant ListHD059217 / HD / NICHD NIH HHS / United States
R01 HD059217 / HD / NICHD NIH HHS / United States