Molecular and functional characterization of the odorant receptor2 (OR2) in the tiger mosquito Aedes albopictus.

In mosquitoes, the olfactory system plays a crucial role in many types of behavior, including nectar feeding, host preference selection and oviposition. Aedes albopictus, known also as the tiger mosquito, is an anthropophilic species, which in the last few years, due to its strong ecological plasticity, has spread throughout the world. Although long considered only a secondary vector of viruses, the potential of its vector capacity may constitute a threat to public health.

Fruitless alternative splicing and sex behaviour in insects: an ancient and unforgettable love story?

Courtship behaviours are common features of animal species that reproduce sexually. Typically, males are involved in courting females. Insects display an astonishing variety of courtship strategies primarily based on innate stereotyped responses to various external stimuli.

The gene transformer of anastrepha fruit flies (Diptera, tephritidae) and its evolution in insects.

In the tephritids Ceratitis capitata and Bactrocera oleae, the gene transformer acts as the memory device for sex determination, via an auto-regulatory function; and functional Tra protein is produced only in females. This paper investigates the evolution of the gene tra, which was characterised in twelve tephritid species belonging to the less extensively analysed genus Anastrepha. Our study provided the following major conclusions.

Evolutionary conservation of Ceratitis capitata transformer gene function.

Transformer functions as a binary switch gene in the sex determination and sexual differentiation of Drosophila melanogaster and Ceratitis capitata, two insect species that separated nearly 100 million years ago. The TRA protein is required for female differentiation of XX individuals, while XY individuals express smaller, presumably nonfunctional TRA peptides and consequently develop into adult males. In both species, tra confers female sexual identity through a well-conserved double-sex gene.

The transformer gene in Ceratitis capitata provides a genetic basis for selecting and remembering the sexual fate.

The medfly Ceratitis capitata contains a gene (Cctra) with structural and functional homology to the Drosophila melanogaster sex-determining gene transformer (tra). Similar to tra in Drosophila, Cctra is regulated by alternative splicing such that only females can encode a full-length protein. In contrast to Drosophila, however, where tra is a subordinate target of Sex-lethal (Sxl), Cctra seems to initiate an autoregulatory mechanism in XX embryos that provides continuous tra female-specific function and act as a cellular memory maintaining the female pathway.