Figure 5
From: Distinct genetic programs guide Drosophila circular and longitudinal visceral myoblast fusion
Longitudinal muscle development is disturbed in lmd, mbc, blow, and kette mutants. (A–C) lmdE202, (D–F) mbcC1/mbcD112, (G–I) blow2 and blow1/blow2, and (J–L) ketteJ-48/ketteG1–37 mutant embryos carrying the reporter construct HLH54F-lacZ and labeled with anti-β-Gal (green), anti-FasciclinIII (anti-FasIII, red in D–F and J–L, blue in I) and anti-β3-Tubulin (anti-β3Tub, blue in D, F, J–L and red in A–C, G, H). (A) Unfused longitudinal muscles in an lmdE202 mutant embryo at stage 14. (B and C) Properly oriented protrusions (arrows in B, inset) and initial midgut chambering (arrow in C) in an lmdE202 mutant embryo at late embryogenesis. (D) Longitudinal visceral muscle migration in a transheterozygous mbcC1/mbcD112 mutant embryo. Arrows point to aberrantly migrating longitudinal FCs. (E–F) Reduction of β-Gal- positive cells and abnormal protrusion formation (arrow in E, inset) in a transheterozygous mbcC1/mbcD112 mutant embryo at stage 16. Arrow in (F) points to region of the midgut not covered by longitudinal FCs. (G) Longitudinal FCs migrating all over the circular muscles in a blow2 mutant embryo during mid-embryogenesis. (H) Mononucleated longitudinal FCs forming protrusions in random directions (double arrow; inset is a magnification of the area) in a blow1/blow2 embryo. (I) blow2 embryo showing defects in constriction formation (arrow) and gaps (arrowheads) between the longitudinal cells; compare to less severe phenotype of blow2/blow1 transheterozygous embryo in (H). (J) Transheterozygous ketteJ4–48/ketteG1–37 mutant embryo with longitudinal FCs along circular muscles. Some cells were not attached to the circular visceral track (arrows). (K and L) ketteJ4–48/ketteG1–37 mutant embryo at the end of embryogenesis, with thin cell protrusions (double arrows in K; inset is a magnification) of the longitudinal FCs. Stretched, mononucleated longitudinal muscles at the end of embryogenesis in blow2(M) and ketteJ4–48(N) mutant embryos. Arrows point to nuclei of longitudinal muscles, marked by anti-DMef2 staining.