PhD, Research Professor at the CSIC.
Passeig Maritim 37, 08003 Barcelona
E-mail: xavier.belles [at] ibe.upf-csic.es
Telephone: +34 93 230 96 36
Fax: +34 93 221 10 11
The historical antecedents
Historically, our goals and interests have been traditionally diverse, trying to embrace a number subjects around the physiology of the insect. In general, research has focused on physiological processes regulated by hormones. Therefore, we have studied the biochemical and regulatory aspects of the hormones themselves (juvenile hormone, ecdysteroids and regulatory peptides), and also the processes dependent on them, like metamorphosis and vitellogenesis (especially in connexion with juvenile hormone and ecdysteroids), molting, oogenesis and chorion formation (in connexion with ecdysteroids) and food intake and growth (in connexion with peptides and proteins). .
The present research
The endocrine regulation of insect metamorphosis has been a long term theme of research and training in the Belles group, which started in the late 1970's. We are interested in the regulation of metamorphosis not only from a developmental point of view but also from an evolutionary perspective. As most information has been obtained in holometabolan species (mainly in the fly Drosophila melanogaster and the beetle Tribolium castaneum), we focus our research on the cockroach Blattella germanica, a phylogenetically basal species showing a gradual metamorphosis that might be close to the ancestral hemimetaboly. We aim at elucidating the mechanisms that regulate metamorphosis in B. germanica and then to compare them with those operating in holometabolan species. The idea is to infer the evolutionary history and the molecular mechanisms underlying the transition from hemimetaboly to holometaboly.
Insect metamorphosis is a complex process, and we concentrate on three main subjects: 1) qualitative metamorphic changes, 2) transcription factors involved, 3) small RNAs, and 4) complex networks.