Table 1.

Summary of laminin α subunit gene expression, protein distribution and membrane morphology

Laminin α subunit gene expression Laminin α subunit distribution
Tissue/cellsBasement membrane/extracellular matrix*EmbryoLarvaeEmbryoLarvae
Sublateral nervesThinαAαA
Ventral nerve cordThinαAαA
Nerve ringThinαAαA
EpidermisThin lam-3 αBαB
Excretory canalThinαA, αBαA, αB
Pharyngeal epitheliumVery thick epi-1, lam-3 lam-3 αA, αBαA, αB
PharynxVery thick epi-1, lam-3 lam-3 αA, αBαA, αB
Pharyngeal-intestinal valveVery thickαA, αBαA, αB
IntestineThin epi-1, lam-3 epi-1 αA, αBαA, αB
Muscles
    Body wallVery thick/thin epi-1 epi-1 αA, αBαB
    VulvalVery thick/thin epi-1 epi-1 αBαB
    IntestinalVery thick/thin epi-1 αBαB
    Anal depressorVery thick/thin epi-1 epi-1 αBαB
    Male tail bursa, etc.Very thick/thinαBαB
Gonad
    Germ cellsThinαB
    Gonad sheathThin epi-1 αB
    Uterine epitheliumVery thick/thin epi-1 αB
    Spermatheca and valveThick epi-1, lam-3 αA, αB
    Distal tip cellsThick epi-1 αB
    OocytesThick
CoelomocytesNDαA, αB
  • ND, not determined.

  • * Although these measurements are fixation sensitive, thin membranes are typically 20 nm across, including the `lollypop' layer, thick membranes are typically 40 nm across and very thick membranes are typically 50-100 nm across (see Figs S4 and S5 at http://dev.biologists.org/supplemental/)

  • Thickened basement membrane facing the epidermis/cuticle and a thin membrane elsewhere (see Fig. S5 at http://dev.biologists.org/supplemental/)