Females heterozygous for tlk^Δ14 exhibit normal mitotic spindle morphology.

At 25^oC females with mutant germ-line clones are sterile, layoing a small number of eggs that collapse shortly after deposition. At 18^oC these females lay eggs that look normal, but a substantial portion of them appear to be shorter than wild type. Mutant embryos fail to hatch, and about two-thirds die during the first nine nuclear divisions. These embryos are usually devoid of DNA - those that do appear to be undergoing apoptosis. The other embryos form a syncitial blastoderm and only 12.5% of total embryos initiate gastrulation. these embryos harbour a number of distinct defects: The early nuclear divisions are asynchronous, as revealed by the appearance of both interphase and anaphase nuclei that is rarely observed in wild-type embryos. Furthermore, nuclei are connected by elongated DNA bridges indicating incomplete chromosomal segregation. Moreover, nuclei are heterogeneous in size and the DNA of the enlarged nuclei have a uniform cloudy appearance with some strongly stained DNA spots. When clones of tlk^Δ14 cells are made in the imaginal disc, they are able to form clones of up to eight cells, and then dissappear from the growing tissue.