Generation of "iro" mutant clones (araDFM3 caupDFM3 mirrDFM3 mutants) in the eye results in dorsal axons projecting to the ventral lamina in 32.4% of cases. In "iro" fz2C1 double mutant clones, 'dorsal-to-ventral' R axon misroutings are observed in 3.5% of the cases. Instead, abnormal bundles of dorsal axons are found.
Homozygous Df(3L)iro-DFM3 clones generate ectopic equators in the dorsal compartment of the eye. These ectopic equators re-pattern eye polarity, such that mirror image ommatidia are seen at the interface between the clonal and wild-type tissue.
Clones homozygous for Df(3L)iro-DFM3 induced during the first larval instar stage show conspicuous transformations of the dorsal head capsule. The most common transformation is a dorsal enlargement of the eye at the expense of the head capsule, or the appearance of ectopic eyes on the head capsule. Many of the clones that give rise to ectopic or enlarged eyes also show additional transformations of the dorsal cuticle to ventral structures, namely, ptilinum, suborbital bristles and prefrons and ectopic antenna and maxillary palpus structures (these structures also form a series, so that a clone displaying a given ventral structure in this series generally also shows those structures preceeding it in the series). The ectopic structures always appear as mirror images of the endogenous ones with a conserved dorsoventral arrangement. This causes the ventralmost ectopic structure, the maxillary palpus, to arise on the back of the head. The appearance of ectopic structures is accompanied by loss of dorsal capsule elements such as ocellar bristles and ocelli. Ectopic prefrons, antenna, rostral membrane and maxillary palpus structures formed in head capsules containing clones homozygous for Df(3L)iro-DFM3 consist exclusively of mutant tissue, while non-autonomous effects are seen in the wild-type head cuticle located between the endogenous and ectopic eye (the cuticle shows duplicate sets of supraorbital bristles in mirror-image arrangements), and in the ectopic eyes themselves. Transformations of head capsule are also seen in clones homozygous for Df(3L)iro-DFM3 that are not associated with ectopic or enlarged eyes and are restricted to one or two types of ectopic ventral structure (ectopic ptilina and prefrons). These transformations are the most common in later-induced clones (induced 48-72 and 72-96 hours after egg laying). These late clones can also give rise to suborbital bristles or the most proximal part of the antenna. Clones homozygous for Df(3L)iro-DFM3 in the eye/antenna disc can be grouped into two categories. Firstly, clones where the general morphology of the disc is not affected and their size is roughly similar to that of their twin wild-type clone. Secondly, clones that show extra proliferation and form large outgrowths of mutant tissue. These clones arise from anterior/dorsal regions of the eye disc and always reach the disc margin. In the most extreme cases, these outgrowths can be recognised as complete or near complete duplications of the ventral parts of the eye disc and antenna disc.
Homozygous Df(3L)iro-DFM3 (containing araDFM3, mirrDFM3 and removing caup) clones cause a series of phenotypes, adding progressively more 'ventral-type' tissue in the following order: dorsal eye overgrowth or ectopic dorsal eyes, overgrowth of ventral type of cuticle (ptilinum and rostral membrane) ectopic antennal pouches, antenna and maxillary palps. The extra head structures are produced autonomously, but the eyes can be composed of both mutant and wild-type ommatidia. The ectopic ventral structures, all grow from the orbital region of the head. The rest of the dorsal head is displaced by the over-grown tissue.
Clones homozygous for Df(3L)iro-DFM3 (a deficiency for ara, caup and mirr) in the dorsal part of the eye which abut the eye disc margin are often associated with extensive outgrowths, which include both mutant and adjacent wild-type cells. A subset of these clones develop a clearly independent eye consisting of both mutant and wild-type cells. These mosaic eyes contain an ectopic equator, with wild-type ommatidia as far as 7 ommatidial rows away from the clonal border being repolarised towards it. Clones homozygous for Df(3L)iro-DFM3 in the dorsal head capsule cause autonomous transformations to ventral cuticle structures. Mutant cells in clones homozygous for Df(3L)iro-DFM3 in the dorsal part of the eye differentiate ommatidia normally, but they form compact patches with smooth borders, as if to minimise contact with surrounding cells. Clones in the ventral part of the eye disc have wiggly contours. Clones of dorsal origin are found in the ventral part of the eye disc. Such clones form straight boundaries with dorsal cells, but wiggly boundaries with ventral cells.