Fig. 4. Localization of Laminin B. Wild-type animals were stained using Laminin B antibodies. (A) The Laminin B protein is detected in the late gastrula between the rows of intestinal (i) and pharyngeal (p) precursor cells, the flanking myoblast cells (m), and the epidermal cells (e). Mid-plane optical section. (B) Laminin B is localized to the muscle and epidermis basement membranes in late stage embryos, larvae and adults. The protein has different distribution patterns in the pseudocoelom/epidermis (p/e) and muscle/epidermis (m/e) basement membranes. Lateral view showing two muscle quadrants, each two cells wide. The muscle cells are anchored to the epidermis through connections involving the muscle/epidermis basement membrane. The lateral epidermal ridge separates the quadrants. (C) In L3 and L4 larvae, Laminin B is localized to the gonad basement membrane and is associated with the distal tip cell (dtc), a migratory cell that helps form the gonad (g). (D) In late stage embryos, larvae and adults, Laminin B is localized to the basement membranes that separate the intestine (i), rectal epithelium (a; anus), epidermis and pseudocoelom. (E) Laminin B is localized to the basement membrane that encloses the gonad (g) primordium cells in the L1 and L2 larval stages. (F) Laminin B is detected in the basement membranes associated with intestinal muscle (im) and anal depressor muscle (am). (G) Laminin B is detected in vulval muscle (vm) basement membrane and somatic gonad (g; uterine epithelium and/or uterine muscle). Staining of all specialized muscles is asymmetric: stronger near their anchorage to bodywall or other epithelia. (H) Laminin B is associated with coelomocytes (cc). Scale bars: 20 µm for A-E.