Molecular cloning and expression of nanos in the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae)

• Ceratitis capitata nanos (Ccnos) gene structure differs from other dipterans.
• Ccnos expression starts late during oogenesis.
• Ccnos mRNA can be detected until germ band elongation at the primordial germ cells.
• Ccnos expression similar to cyclorrhaphan but not to non-cyclorrhaphan dipterans.

The gene nanos (nos) is a maternal-effect gene that plays an important role in posterior patterning and germ cell development in early stage embryos. nos is known from several diverse insect species, but has so far not been described for any Tephritid fruit fly. Here, we report the molecular cloning and expression pattern of the nos orthologous gene, Ccnos, in the Mediterranean fruit fly Ceratitis capitata, which is a destructive pest of high agricultural importance. CcNOS contains 398 amino acids and has a C-terminal region with two conserved CCHC zinc-binding motifs known to be essential for NOS function. Transcripts of Ccnos were confirmed by in situ hybridization to be maternally-derived and localized to the posterior pole of early stage embryos. Regulatory regions of nos have been employed in genetic engineering in some dipterans such as Drosophila and mosquitoes. Given the similarity in spatial and temporal expression between Ccnos and nos orthologs from other dipterans, its regulatory regions will be valuable to generate additional genetic tools that can be applied for engineering purposes to improve the fight against this devastating pest.