Meeting Abstract

P1.57  Friday, Jan. 4  Determining the putative source of a morphogen underlying black spot development in Pieris rapae butterflies WALKER, J.F.*; MONTEIRO, A; Purdue University; Yale University jfwalker@purdue.edu

Presented here is the outcomes involved in disrupting putative sources of morphogen underlying black spot development in the pupal wings of the butterfly Pieris rapae and a protocol for methods of measuring alterations to the resulting adult color pattern. Morphogens are signaling molecules that once secreted by the producing cells typically travel through tissues to affect the regulation of genes in surrounding cells in a concentration-dependent manner. Eyespot patterns in lineages of nymphalid butterflies (one of the five major butterfly families) are induced by one or more morphogens produced by central cells, as disruption of these cells eliminates or reduces eyespots, and their transplantation to novel locations on the wing induces eyespot patterns. Little is known, however, about the developmental mechanisms underlying the differentiation of the simpler spot patterns in the earlier splitting lineage of pierid butterflies. This study examines the formation of wing spots in P. rapae, which we hypothesize to be the result of one central source of morphogen. We tested whether one or more sources of morphogen positioned at the center or just off-center to P.rapae slightly dumbbell shaped spots underlies their differentiation. To test this, wings at the spot location were pierced at several time points after pupation, and the resultant right and left (control) wing spot patterns were photographed. We performed comparative image analysis to determine whether the experimental spots have been altered in shape and size. Our results suggest that there is a single source of morphogen, located in the center of the future spot pattern, responsible for spot differentiation in P. rapae.