OMMOCHROME PIGMENTATION OF THE LINEA AND ROSA SEASONAL FORMS OF PRECIS-COENIA (LEPIDOPTERA, NYMPHALIDAE)

Precis coenia exhibits a seasonal color polyphenism. Animals reared un der long-day conditions develop a pale tan pigmentation on their ventr al hind wing (the linea form), whereas animals reared under short-day conditions develop a dark reddish-brown pigmentation (the rosa form). This developmental switch is mediated by a shift in the timing of ecdy steroid secretion at the outset of adult development. In addition, a s ingle recessive gene mimics the effect of short-day conditions and, wh en homozygous, produces a constitutive rosa phenotype. This article an alyzes the pigment composition of the ventral hind wing pattern of the linea and rosa forms. It presents a new thin layer chromatography sys tem that separates ommochromes with high resolution. The linea pigment ation was found to be due to xanthommatin, while the rosa pigmentation is due to a mixture dihydro-xanthommatin and ommatin-D. Induction of the rosa form thus requires the synthesis of a new pigment (ommatin-D is a sulfate of dihydro-xanthommatin) and the stabilization of the red uced form of xanthommatin. (C) 1997 Wiley-Liss Inc.