Condensation of DNA in the oocyte nucleus to form the karyosome is aberrant in homozygous egg chambers. In some cases the DNA forms an ellipsoidal shape that is larger than normal, and in other cases the DNA is present in clumps that line the inside of the nuclear membrane.
Maternal effect mutation similar to spn-A. Embryos sometimes hatch.
spn-Dunspecified is rescued by spn-D+Aa