Fig. 6. Laminin A and Laminin B segregate to different basement membranes. Immunofluorescence micrograph of embryos co-stained with Laminin A (red) and Laminin B (green) antibodies. (A) By late gastrulation, both subunits are deposited between the germ layers. While staining for Laminin A is intense around the pharyngeal precursors (p), both subunits are detected between the muscle (m), intestinal (i) and epidermal (e) precursor cells. (B) As the embryo elongates, areas of distinct Laminin A and Laminin B composition can be distinguished between the developing pharynx/intestine (arrowheads) and body wall muscle (arrows). (C) Co-staining of a late stage mnDf90 embryo, in which the pharynx and intestine has detached from the body wall muscle. Laminin A associates with the pharynx and intestine (large arrows) and Laminin B associates with the body wall muscles (arrowheads), suggesting that these basement membranes, which are juxtaposed in wild-type animals, each retain a unique subunit composition. Juxtaposed muscle/epidermis associated membranes appear yellow (small arrows). Anterior is towards the left, dorsal towards the top. Scale bars: 10 µm.