Meloe

Abstract: These parasites get into bees' nests by fooling males into trying to mate with them. The life cycles of parasites often involve complex behavioural and morphological adaptations in order to find a host. Here we report a remarkable mode of host-finding by the blister beetle Meloe franciscanus, in which young larvae aggregate together on vegetation to mimic the appearance of a female bee, luring male bees to land on them and collect the aggregation as a unit for transmitting to females during real matings. Although cooperative behaviour is common among highly social insects, particularly bees1,2,3, to our knowledge it has not been reported before in blister beetles, nor has it been associated with mimicry.

Abstract: Our previous studies on melanoma antigens identified two new polypeptides, named MELOE-1 and MELOE-2, that are involved in immunosurveillance. Intriguingly, these antigens are coded by distinct open reading frames (ORF) of the meloe mRNA which is significantly expressed only in the melanocytic lineage. In addition, MELOE-1 and -2 specific T cell clones recognized melanoma cells but very poorly normal melanocytes suggesting differential translation of meloe in normal vs tumor cells. This prompted us to elucidate the mechanisms of translation of these antigens in melanoma cells. We first demonstrated that no splicing event or cryptic promoter could generate shorter meloe transcripts containing only one of the two ORFs. Triggering meloe RNA degradation with a siRNA close to the ORF coding for MELOE-2 abrogated expression of both MELOE-1 and MELOE-2, thus confirming that the two ORFs are always associated. Next we showed, in a bicistronic reporter system, that IRES activities could be detected upstream of MELOE-1 and MELOE-2 and finally confirmed their translation from full length meloe cDNA in melanoma cells with eGFP constructs. In conclusion, meloe is a polycistronic mRNA that generates both MELOE-1 and MELOE-2 antigens through IRES-dependent translation in melanoma cells and that may explain their tumor specificity.

Abstract: Meloe majalis Linne, a west Mediterranean species of Meloidae, is referred to the Lyttini instead of the Meloini on the basis of larval morphology and biology. The new genus Berberomeloe is established for this species. Berberomeloe differs from Trichomeloe, a wingless and brachyelytrous east Mediterranean genus of Lyttini, particularly in the shape of the antennae, pronotum, abdomen and genitalia, and in body pubescence. The first instar larva of Berberomeloe is non‐phoretic and parasitizes Apoidea; the larva shows some primitive morphological characters. The systematic affinities of Berberomeloe are not yet recognizable. The geographic distribution and bionomics of B. majalis are also discussed.