Molecular cloning, by a novel approach, of a cDNA encoding a putative olfactory protein in the labial palps of the moth Cactoblastis cactorum.
We have used the CapFinder technology, without the library construction step, to amplify and clone full-length cDNAs expressed in the labial palps (CO2-sensing organs) of the moth Cactoblastis cactorum. The validity of our approach is exemplified by the sequence analysis of a 597-bp cDNA clone, designated CLP-1, that contains a 390-bp open reading frame (ORF) flanked by motifs characteristic to a full-length cDNA. The ORF in CLP-1 encodes a predicted polypeptide that is 47% identical to a novel protein, OS-D, found exclusively in the olfactory antennal segment of Drosophila melanogaster. Both CLP-1 and OS-D have primary structures that do not bear sequence similarity to any previously characterised proteins including odorant-binding proteins (OBPs) in vertebrates and pheromone-binding proteins (PBPs) in moths. Although they share features common to OBPs and PBPs, such as the presence of signal peptides and cysteine motifs, they clearly belong to a distinct class of olfactory proteins that appear to be unique to insects. The relative abundance of the CLP-1 message in the labial palps of females leads to the suggestion that this protein is involved in the CO2-sensing cascade. Our results suggest that the experimental procedure can be used as an alternative, rapid method to identify genes expressed in a particular organ, or tissue, especially in situations when the amount of available tissue is a limiting factor.
Maleszka
R
R
Visual Sciences, Research School of Biological Sciences, The Australian National University, Canberra, ACT. maleszka@rsbs-central.anu.edu.au
Stange
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification*; D029721:Drosophila Proteins; D005260:Female; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D009036:Moths / Q000235:genetics*; D012679:Sense Organs / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
C109782:CLP-1 protein, Cactoblastis cactorum; D002352:Carrier Proteins; D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; C109787:a10 protein, Drosophila