polo¹/+ gwl^scant/+ double heterozygous females are nearly sterile. This phenotype is partially suppressed if the females are also heterozygous for either endos^EY01105 or endos^EY01103.

No adult progeny are recovered from polo¹¹/+ gwl^scant/+ double heterozygous females mated to wild-type males.

Heterozygosity for either tws^aar-1, tws^j11C8 or mts^XE-2202 enhances the reduced fertility phenotype of polo¹/+ gwl^scant/+ double heterozygous females, such that in each case the triple heterozygotes are completely sterile.

endos^+tRa enhances the reduced fertility phenotype of polo¹/+ gwl^scant/+ double heterozygous females, such that in each case the triple heterozygotes are completely sterile.

The embryos resulting from the cross between gwl^scant/+, Df(3R)ED5474/+ mothers and wild-type fathers fail to hatch.

Compared with wild-type controls, a lower than expected proportion of the embryos hatch resulting from the cross between gwl^scant/+, Df(2L)ED12527/+ mothers and wild-type fathers.

Compared with wild-type controls, a lower than expected proportion of the embryos hatch resulting from the cross between gwl^scant/+, Df(2L)ED1315/+ mothers and wild-type fathers.

Compared with wild-type controls, a lower than expected proportion of the embryos hatch resulting from the cross between gwl^scant/+, Df(3L)ED4483/+ mothers and wild-type fathers.

Compared with wild-type controls, a lower than expected proportion of the embryos hatch resulting from the cross between gwl^scant/+, Df(3L)ED4486/+ mothers and wild-type fathers.

Compared with wild-type controls, a lower than expected proportion of the embryos hatch resulting from the cross between gwl^scant/+, Df(3R)ED5330/+ mothers and wild-type fathers.

The embryos resulting from the cross between gwl^scant/+, mts^XE-2258/+ mothers and wild-type fathers fail to hatch.

The embryos resulting from the cross between gwl^scant/+, tws^j11C8/+ mothers and wild-type fathers fail to hatch.

polo¹ gwl^scant double heterozygous females produce 4% as many progeny as controls.

polo¹ gwl^scant mitotic nuclei exhibit centrosomal loss in just under approximately 60% of syncytial embryos.

polo¹ gwl^scant double heterozygous females produce embryos that frequently display centrosome disassociation from one pole. There is a slight but significant increase in defective spindles in embryos derived from polo¹ gwl^scant mutants compared to controls, indicating that a single mutant copy of these genes in mothers leads to mitotic defects at a low frequency. However, these embryos always hatch and develop fully, indicating that such low frequencies of defects can be tolerated.

Females heterozygous for both polo¹¹ and gwl^scant lay eggs that die during development. These females lay normal numbers of eggs that do not hatch but do begin to develop and turn brown.

polo¹¹ gwl^scant mitotic nuclei exhibit centrosomal loss in approximately 90% of syncytial embryos.

polo¹¹ gwl^scant double heterozygous females produce embryos that frequently display centrosome disassociation from one pole. There is a slight but significant increase in defective spindles in embryos derived from polo¹¹ gwl^scant mutants compared to controls, indicating that a single mutant copy of these genes in mothers leads to mitotic defects at a low frequency.

polo¹¹ gwl^scant double heterozygous-derived embryos show an initial detachment of one centrosome early in mitosis, before nuclear envelope breakdown. The free centrosome drifts away from the nucleus, and astral microtubule formation usually appears normal, though there is no asymmetric microtubule enhancement. A half-spindle is established by microtubules forming connections between the chromosomes and the centrosome still associated with the nuclear envelope. However, spindle bipolarity is often attained by microtubules growing from the chromosomes outwards. If a free centrosome is sufficiently close to this second half-spindle, it can reattach it to form a normal bipolar spindle containing two centrosomes and nuclear division completes normally. However, if the free centrosome drifts too far away from its spindle, it cannot be recaptured, and the monoastral spindle that forms initially is unfocussed at the pole lacking a centrosome. In some cases, monoastral bipolar spindles fuse with neighboring spindles and degenerate to give interconnecting arrays of microtubules. In other cases, the acentrosomal pole eventually focuses and anaphase occurs.