(040527 revised, 040527 created)
Umebachi Y, Osanai M.
Perturbation of the wing color pattern of a swallowtail
butterfly, Papilio xuthus, induced by acid
carboxypeptidase.
Zoolog Sci. 2003 Mar;20(3):325-31.
Hypodermal injection of Toughmac-E, a digestive mixture
composed of nine digestive components, or Molsin induced
perturbation of the wing color pattern in 0- to 2-day-old
pupae of Papilio xuthus, but had no effect on prepupae or
3- to 4-day-old pupae. The effective component in
Toughmac-E was identified as Molsin, an acid
carboxypeptidase of Aspergillus saitoi which specifically
liberates tyrosine and phenylalanine from the C-terminal
residues of proteins. The pattern perturbation occurred in
either side of the fore- and hindwings of both sexes. When
this enzyme was administered, stronger melanization than in the normal wings was found in the whole wings of most
butterflies, but in other butterflies, the yellow region
was enlarged. These findings suggest that the pattern
perturbation was caused by changes in the levels of
melanin and papiliochromes in scales. Melanin is a black
pigment and papiliochromes are yellow pigments; their
common precursor is dopamine. The normal pattern is formed
by a predetermined balance of melanin and papiliochromes,
whereas the deposit of an excess amount of tyrosine and/or
phenylalanine disturbs this balance and results in
perturbation of the color pattern. Administration of
L-dopa or dopamine had no effect on the wing pattern. When
the activity of an endogenous acid carboxypeptidase
similar to Molsin appears in the early pupa, the summed
activities of the endogenous and exogenous acid
carboxypeptidases must induce a pattern perturbation. The
relations between the endogenous acid carboxypeptidase and
its probable substrate, the reserve protein, and the
physiological roles of these relations in the regulation,
utilization and excretion of amino acids are discussed.
Papilio xuthus: English name: Chinese yellow swallowtail (Citrus swallowtail, Asian swallowtail). Japanese name: Ageha (Nami-ageha) ƒiƒ~ƒAƒQƒn.