The majority of Lam¹⁴ and Lam¹⁴/Df(2L)GpdhA mutants die at the pharate adult stage and the rest die throughout the pupal stage. Under 1% of these mutants eclose; such animals have severe defects in walking and flying and die within a few days. Lam¹⁴ mutants that fail to eclose remain alive in the puparium for at least 2 days after the onset of the pharate adult stage and show muscle contractions. Lam¹⁴/+ mutants fully eclose and exhibit no defects in walking or flying. 45% of Lam¹⁴/Lam^P transheterozygotes eclose and resulting adults show defects in walking and flying. Mitotic structures and overall nuclear shape are normal in larval and late pupal stages for Lam¹⁴ mutants. However, the nuclear envelope is abnormal in the larval CNS of these mutants; nucleoporins are clustered, although the structure of individual nucleoporins is normal. Clustering coincides with an absence of LamC protein. Developmental abnormalities occur during late pupal stages before Lam¹⁴ mutants die. For example, the ventral ganglia of Lam¹⁴ mutants is underdeveloped, with thoracic neuromeres showing incomplete expansion. Lam¹⁴ eyes show a nuclear migration defect and have an accumulation of red pigmented material. The ventral abdominal exoskeleton of mutants in late pupa is partially transparent. Egg chambers of Lam¹⁴ females fail to develop beyond stage 6 or 7 and by the pharate adult stage, Lam¹⁴ ovaries are smaller than wild type and contain cystocytes with unusually large nuclei. Male Lam¹⁴ gonads also arrest development at an unusually early stage. The ventriculus of Lam¹⁴ mutants in late pupal stages is ~3- to 5-fold larger than wild type. This phenotype appears to result from increased cell proliferation as the ventriculus of newly-eclosed Lam¹⁴ adults contain between 32 and 112 dividing cells, compared to ~3 dividing cells in the wild-type ventriculus at this stage. Muscle structure is similar to wild type in the Lam¹⁴ ventriculus, but longitudinal muscle fibers are slightly thicker and appear to contain less nuclei than wild type. The distribution of epithelial cells beneath the muscle layer is not different to wild type.

Lam¹⁴ has adult midgut phenotype, suppressible by EcR^B1.hs