Capicua maintains anterior-posterior axis in Blattella germanica ovaries

The establishment of the symmetry axis is crucial for the development of all organisms. In insects, this process begins early in oogenesis with the correct distribution of the mRNAs and proteins in the oocyte. One of the proteins that contribute to organizing this distribution is Capicua (Cic). Cic has been studied in Drosophila melanogaster oogenesis and embryo development, it is maternally expressed and is required to establish the dorso-ventral axis, acting as a repressor transcription factor. Although the sequence of Cic is conserved across species, its function in other types of insect ovaries is still unknown. We wondered whether the function of Cic in insects has been maintained through evolution despite the ovary type or if it has been modified in parallel to the ovary evolution. To address this, we studied the Cic function in a phylogenetically basal insect, the cockroach Blattella germanica , a species with panoistic ovaries. The Cic sequence of B. germanica shares 80% identity with D. melanogaster Cic. Our findings indicate that Cic is essential for oocyte development as it is involved in establishing the anterior- posterior axis.