Biohistory Research Hall, 1-1 Murasaki-cho, Takatsuki-shi, Osaka 569, Japan
(Received July 31, 1993; Accepted August 30, 1993)
Keywords: competition, lateral inhibition, cellular pattern, cell number ratio, insects
Abstract. In the early phase of development in the pupal wing epidermis of a butterfly, Pieris rapae, scale precursor cells are differentiated and evenly-distributed in the wing epidermis. This cellular pattern is developed from an ensemble of homogeneous undifferentiated epidermal cells. The developmental mechanism of the spatial pattern and the number ratio of differentiated cells to the total ones are explained by the model under competition and lateral inhibition of neighboring cells. This model is also applicable to the early neurogenesis in the fly and grasshopper embryos.