Forma, Vol. 27 (Special Issue), pp. S1-S8, 2012

Essence of Shape Formation of Animals

Hisao Honda

Hyogo University, Kakogawa, Hyogo 675-0195, Japan
E-mail address:,

(Received January 23, 2012; Accepted March 16, 2012)

Abstract. Although the shapes of multi-cellular animals are diverse, they share the simple unifying principle that each of their bodies is completely enclosed by an envelope of epithelium. In the course of development, the envelope becomes highly convoluted, resulting in the variety of final animal forms. Furthermore, epithelial cells possess an intrinsic ability to form envelopes automatically in the absence of any extrinsic direction or information. This capacity is derived from the behaviors of ‘apical vesicles’, which are membrane structures created within epithelial cells. Epithelial cells are classified into six cell polarity types, type 0, type 1, type 2, type 3, cup type and tunnel type, which arise from behaviors of apical vesicles.

Keywords: Animal Shape, Apical Vesicle, Epithelial, Cell Polarity Type, Self-Construction

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