Homozygotes die at the end of embryogenesis.

LanB2^knod, LanB2^knod/LanB2^d5A1 and LanB2^knod/Df(3L)Exel6114 stage 16 embryos have a one-chambered, "dumpling-shaped" midgut and often have local accumulations and gaps in the visceral muscles.

LanB2^knod/LanB2^d5A1 embryos lack single somatic muscles at random positions. The ventral oblique muscles in the four anterior segments are not attached to their tendon sites or are completely missing.

The contact between the pericardial cells and the heart tube is lost in mutant embryos, resulting in the dissociation of pericardial cells.

The fat body shows local disruptions in late stage embryos and partially fails to attach to the tip of the incorrectly migrate salivary gland.

The extracellular matrix that surrounds the midgut is scattered in late LanB2^knod embryos and appears only loosely attached to the midgut surface (in contrast to the close association seen in wild type).

Stage 13 LanB2^knod/LanB2^d5A1 embryos show disordered stretching of visceral myotubes.

Stage 13 LanB2^knod embryos show a delay in the fusion of the anterior and posterior midgut primordia.

The migration of longitudinal visceral muscles along the visceral mesoderm is reduced compared to wild type in stage 12 LanB2^knod embryos and the mutant migrating muscle cells have an aberrant shape.

Mutants show defects in visceral mesoderm development.