(050627 revised, 050627 created)
Ono H, Ozaki K, Yoshikawa H. (2005)
Identification of cytochrome P450 and
glutathione-S-transferase genes preferentially expressed
in chemosensory organs of the swallowtail butterfly,
Papilio xuthus L.
Insect Biochem Mol Biol. 2005 Aug;35(8):837-46.
JT Biohistory Research Hall, 1-1, Murasaki-cho, Takatsuki,
Osaka 569-1126, Japan.
The swallowtail butterfly, Papilio xuthus L., feeds
exclusively on members of the plant family, Rutaceae.
Female butterflies lay eggs in response to specific
chemicals contained in their host plants. They perceive a
variety of polar compounds as oviposition stimulants
through the tarsal chemosensilla of the foreleg by
drumming upon the leaf surface. We undertook an expressed
sequence tag (EST) analysis to identify the
chemosensory-related genes that are expressed in
chemosensilla on the tarsus of P. xuthus. Several genes
that showed similarity with biotransformation enzymes were
identified from the ESTs. Among them, a cytochrome P450
and a glutathione-S-transferase (GST) were preferentially
expressed in the chemosensory organs. We have determined
the structure of both cDNA and genomic sequences encoding
these enzymes and designated the P450 as CYP341A2, a novel
member of CYP341A subfamily, and the GST as GST-pxcs1,
respectively. We observed a localized expression of
CYP341A2 at the base of tarsal chemosensilla by in situ
hybridization. These results suggest that these degrading
enzymes play a role in the chemosensory reception for host
plant recognition.