Homozygous γTub23C^PI/γTub37C¹ mutant females are agametic with rudimentary ovaries. The addition of γTub23C^+tLa or γTub37C^+t7.2 rescues these phenotypes.

In homozygous γTub23C^PI/γTub37C¹ mutant embryos, germ cells form, migrate and populate the gonads as wild-type. Ovaries of mutant second instar larvae are also indistinguishable from wild-type. By the third instar larval stage the number of germ cells is slightly reduced. At prepupa stage, germ cells are found scattered throughout the mutant ovary, their total number is dramatically reduced. From this stage on germ cells degenerate and steadily disappear from the mutant, so that in adult ovaries the germaria are empty.

In homozygous γTub23C^PI/γTub37C¹ mutant third instar larval females, half of the germ-line mitotic figures have centrosomes that are not aligned along the axis of the condensed chromosome plate. The condensation of the chromosomes is too high. Correspondingly, mitotic spindles are composed of shirt, often disorganised, microtubules associated with the chromosomes.

Homozygous γTub37C¹², γTub23C^PI females are sterile but lay a few eggs. Their ovaries are reduced in size and contain only a few egg chambers. Some of the ovaries are completely empty or contain only one or two degenerating egg chambers, whereas others contain some egg chambers at various stages of development, including mature oocytes. These phenotypes are rescued by the addition of either γTub37C^+t7.2 or γTub23C^+tLa.

In γTub37C¹², γTub23C^PI females there are no significant differences between mutant and control in the average number of ovarioles per ovary. However more than half of the ovarioles are empty, and the average number of egg chambers per ovary in the mutant is about eight times less than in heterozygous flies and about half of them are abnormal. Within the egg chambers that develop, about 50% show abnormalities. Most abnormal egg chambers present one of three major phenotypes: degenerating egg chambers with pycnotic DNA, egg chambers with 14 nurse cells and two oocyte-like nuclei and compound egg chambers that contain >16 cells. the remaining abnormal egg chambers show a variety of phenotypes, which occur at a lower frequency. These include egg chambers with <16 germ cells, egg chambers with misplaced oocyte or abnormally shaped oocyte nucleus, oocytes containing endoreplicated nuclei, reduced oocyte growth, abnormal positioning of the dorsal appendages, and egg chambers containing 16 nurse cells and no oocyte.

A high percentage of the abnormal egg chambers found in γTub37C¹², γTub23C^PI double mutant females contain 14 nurse cell nuclei and two oocyte-like nuclei. In these cases, one of the two oocyte-like nuclei is always located posteriorly and within one of the four ring-canal cells of the cyst, like a wild-type oocyte. The second oocyte-like nucleus, on the other hand, can be found anywhere within the egg chamber, in cells with any number of ring canals. Thus, the ectopic oocyte-like nucleus does not belong to the second pro-oocyte. The level of endoreduplication of the ectopic oocyte-like nucleus is variable. The 14 + 2 egg chamber phenotype was never observed after stage 10.

γTub23C^PI ; asl^unspecified double mutant spermatocytes lack organised spindles.