Homozygous chb⁶ germline cells transplanted into female hosts with a non-functional germline and wild-type soma result in chimeric females that are sterile. Wild-type germline cells transplanted into chb⁶ homozygous females result in chimeric females that produce wild-type offspring. These experiments suggest that chb⁶ affects only the female germline and not the soma.

chb⁵/chb⁶ and chb⁶/Df(3L)Pc-MK females have small ovaries and only a few egg chambers are found in about one-fifth of the mutant ovaries. Oogenesis never proceeds beyond mid-oogenesis.

Homozygous females have small ovaries and only a few egg chambers are found in about one-fifth of the mutant ovaries. The egg chambers contain fewer than 16 germline cells. They show no oocyte differentiation with all the germline cells adopting the nurse cell fate.

Defects in the structure of the ovariole niche are seen in homozygous females; fusome-containing stem cells that are associated with the terminal filament and cap cells in the ovariolar niche can be recognised in about 50% of germaria in newly emerged and 1 day old females and some cysts develop branched fusomes of normal appearance at later stages. The remaining 50% of germaria of newly emerged and 1 day old females have no fusome material in the ovariolar niche, and thus appear not to contain any stem cells, despite the presence of both terminal filament and cap cells. These ovarioles often contain either aggregates or fragments of fusome material often contacting irregular microtubule bundles located in more distal cysts, suggesting that at one time they contained stem cells. The abnormal germaria predominate in 2-3 day old homozygous females.

The structure of the cystoblast and/or cystocyte spindles is severely affected in the germaria of newly eclosed homozygous females; the spindles are much shorter than those observed in wild-type 2- or 4- cell cysts and are sometimes monopolar. The mitotic index of homozygous cystoblasts-cystocytes is dramatically reduced compared to wild type (0.35 versus 2.7). When spindles do form, they never make contact with the fusome (in contrast to wild type).

Homozygous egg chambers show a range of ring canal defects, the severity of the defects increasing with the age of the female. Many mutant egg chambers have 7 ring canals and 8 nurse cell nuclei, suggesting that the fourth round of mitotic division might have failed in these egg chambers. In other egg chambers, the number of ring canals and nurse cells do not correlate, suggesting a more extensive failure in cell division. Many egg chambers contain between one and six nurse cells and no ring canals, suggesting that germline cyst mitoses had occurred but that cytokinesis had not been completed correctly. The microtubule network of homozygous egg chambers is severely disrupted or completely abolished. The egg chambers of younger females have reduced numbers of microtubules in irregular bundles. A body equivalent to the microtubule-organising centre (MTOC) can be seen in these females, and its position is variable. Microtubule bundles and MTOCs can not be detected in the egg chambers of older females.