(Sauaia and Alves)-An Overview of a Model Organism in Genetics, with New Aspects in Morphology and Systematics.

(Sauaia & Alves, 1968) is a sciarid that has been continuously cultured in the laboratory for nearly 60 years. Studies on this species have contributed to the understanding of DNA puffs, which are characteristic of Sciaridae, and to the knowledge of more general aspects of insect biology, including cell death, nucleolar organization, and the role of the hormone ecdysone during molting. The genome of has now been sequenced, and it is the third publicly available sciarid genome. The aim of this work is to expand the current knowledge on . The morphology of the adults is revisited. The morphology of larvae and pupae is described, together with the behavior of immature stages under laboratory conditions. Cytogenetic maps of the salivary gland polytene chromosomes are presented, together with a comparative analysis of the mitotic chromosomes of six different sciarid species. was originally described as a species of and recently moved to We examine here the systematic position of in the latter genus. Our results extend the characterization of an unconventional model organism and constitute an important resource for those working on the cytogenetics, ecology, taxonomy, and phylogenetic systematics of sciarids.