In tum^DH15/tum^DH15 embryos, VL1, DT1, LO1 and VT1 muscles are missing, or show attachment or elongation defects.

Homozygous embryos show defects in muscle morphology and muscle attachment site selection. These defects are not limited to a specific subset of muscles. Muscles are often curved compared to wild type, and myotubes with ectopic extensions that often attach to the wrong tendon cell or fail to extend towards their normal attachment site are seen. Tendon cells are present, differentiated and in their proper locations in the mutant embryos and mutant muscles do form stable attachments with the tendon cells, as occurs in wild type. Muscle specification and myoblast fusion are not impaired in the mutant embryos. Actin accumulates normally at the sites of muscle attachment in mutant embryos, even when attachments are formed at incorrect locations. The mutant muscles no longer show uniform microtubule polarity at stages 14/15 and 16, in contrast to wild type.

Homozygous embryos have an excess of naked cuticle at the expense of denticles. Most denticles in the mutant belts are similar in size to the smaller denticles normally found in rows 1-4 of the wild-type belt pattern.

Binucleate cells are found in the embryonic epithelium of homozygous tum^DH15 and trans-heterozygous tum^DH15/Df(2R)Exel7128 embryos from stage 11 (extended germ band) onward.

The prominent feature of tum^DH15 mutant embryos is a failure of cell division. A transient loss of tissue integrity during germ band retraction can is noted in some embryos. Late-stage tum^DH15 mutant embryos show defects in nervous system and muscle organisation.

Mitosis in homozygous tum^DH15 embryos is indistinguishable from heterozygous sibling embryos up to until mid-to-late stage 11 (extended germ band), when aberrant telophase figures and a few binucleate cells are observed in the dividing epithelial cells of some of the embryos. Older embryos (stage 12) have binucleate cells and aberrant telophase figures in the epithelium. In many cases, some cells sow no evidence of furrowing at a time in late anaphase when wild-type cells are constricting. However, some cells progress further in cytokinesis than others. The many examples of aberrant microtubule organisation seen in anaphase and telophase cells indicate that cell division is failing after chromosome separation. These tum^DH15 mutant cells have variable microtubule morphologies, ranging from relatively few detectable microtubules with no apparent central spindle, to multiple microtubule bundles.

tum^DH15 has dorsal transverse muscle cell | embryonic stage phenotype, non-enhanceable by polo¹/polo¹

tum^DH15 has muscle cell of lateral oblique muscle 1 | embryonic stage phenotype, non-enhanceable by polo¹/polo¹

tum^DH15 has muscle cell of ventral transverse muscle 1 | embryonic stage phenotype, non-enhanceable by polo¹/polo¹

tum^DH15 has embryonic hypodermal muscle cell | embryonic stage phenotype, non-enhanceable by pav^B200/pav^B200

tum^DH15/tum[+] is a suppressor of wing disc phenotype of Csk^GD9345, Scer\GAL4^ptc-559.1

tum^DH15 is a suppressor of embryonic/first instar larval cuticle phenotype of wg^l-12

tum^DH15 is a suppressor of denticle phenotype of wg^l-12