Melanin-synthesis enzymes coregulate stage-specific larval cuticular markings in the swallowtail butterfly, <Emphasis Type="Italic">Papilio xuthus</Emphasis> |
| |
Authors: | Ryo?Futahashi Email author" target="_blank">Haruhiko?FujiwaraEmail author |
| |
Institution: | (1) Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Bioscience Bldg. 501, Kashiwa, Chiba 277-8562, Japan |
| |
Abstract: | Like the adult wing, butterfly larvae are unique in their coloring. However, the molecular mechanisms underlying the formation
of insect larval color patterns are largely unknown. The larva of the swallowtail butterfly Papilio xuthus changes its color pattern markedly during the 4th ecdysis. We investigated its cuticular color pattern, which is thought
to be composed of melanin and related pigments derived from tyrosine. We cloned three enzymes involved in the melanin-synthesis
pathway in P. xuthus: tyrosine hydroxylase (TH), dopa decarboxylase (DDC), and ebony. Whole-mount in situ hybridization showed that the expression of both TH and DDC is strongly correlated with the black markings. ebony is strongly expressed only in the reddish-brown area. The expression pattern of each enzyme coincides with the cuticular
color pattern of the subsequent instar. We also investigated the uptake of melanin precursors into cultured integument. Inhibition
of either TH or DDC activity prevents in vitro pigmentation completely. Addition of dopamine to integuments in the presence
of TH inhibitor causes overall darkening without specific markings. From these results, specific larval cuticular color patterns
are regulated by stage-specific colocalization of enzymes in epidermal cells rather than by the differential uptake of melanin
precursors into individual epidermal cells. Epidermal cells expressing TH and DDC, but not ebony, produce the black cuticle, and epidermal cells expressing TH, DDC, and ebony produce the reddish-brown cuticle. |
| |
Keywords: | Papilio xuthus Butterfly Color formation Melanin Larval markings |
本文献已被 PubMed SpringerLink 等数据库收录! |
|