Functional redundancy of the three insulin receptors of cockroaches.

Gene duplication is a fundamental evolutionary process which provides opportunities to acquire new gene functions. In the case of the insulin receptors (InRs) in cockroaches and close-related insects, two successive duplications determined the occurrence of three InR genes: InR2, InR1 and InR3, the last two forming a sister cluster to InR2. The biological role of each of the gene duplicates and whether they resulted from neofunctionalization or subfunctionalization is still unclear.

Investigating the origin of insect metamorphosis.

Experiments exploring the role of juvenile hormone during the life cycle of firebrat insects provide clues about the evolution of metamorphosis.

Reduction of embryonic expression as a hypothetical driver of the evolution of insect metamorphosis.

The early embryo of the cockroach exhibits high expression. In general, E93 triggers adult morphogenesis during postembryonic development. Here we show that E93 is also crucial in early embryogenesis in the cockroach, as a significant number of E93-depleted embryos are unable to develop the germ band under maternal RNAi treatment targeting .

Flight or protection: the genes and in the determination of membranous and sclerotized wings in insects.

Present-day pterygote insects have two pairs of wings, one in the mesothorax (T2), the other in the metathorax (T3), and both have diverged in structure and function in different groups. Studies in endopterygote and paraneopteran species have shown that the gene () specifies the identity and wing structure in T3, whereas the gene () significantly contributes to forming modified T2 wings. We wondered whether these and mechanisms operate in the lineage of polyneopterans.