CNRS-UMR 5548, Université de Bourgogne, 6 Bd Gabriel, 21000 Dijon, France.
Chemosensory functions and especially the taste are important for foraging and for mating in the Blattaria. In behavioural tests, we showed that the mating success was significantly reduced by the ablations of differents female organs like antennae, maxillary and labial palps. We deduced that the antennae play a role in the contact recognition and that maxillary and labial palps have an important function in the sensorial evaluation prior to the licking of the male tergal secretions, which is the last step before mating. Recent molecular studies revealed in sensory organs the presence of highly conserved small carrier proteins with a specific cystein motif (Cx8Cx18Cx2C). Many sequences have already been found in different species of insects (Coackroaches, Drosophila, Cactoblastis, Schistocerca, Eurycantha). Those carrier proteins have been located in organs used in chemoreception (antennae, tarses, palps). This suggests that this protein family has a chemosensory function certainly very close to that of Olfactory and/or Pheromone Binding Proteins (carriers or solubilizing helpers for chemosensory signals). In order to find cDNAs corresponding to such proteins in L. maderae, a RT-PCR approach with degenerate primers was performed. A 220bp fragment was cloned and the deduced protein sequence showed a high homology with this chemosensory protein family. The transcript was detected in the antennae, maxillary palps and in the labium of the females.