Kinesin-directed secretion of basement membrane proteins to a subdomain of the basolateral surface in Drosophila epithelial cells

Three morphologically distinct major cell types were observed in primary cultures obtained from the mammary parenchyma of glands from virgin rats. These cell types consisted of small cuboidal epithelial cells, larger epithelioid cells and elongated cells. We have investigated the distribution of the basement membrane proteins laminin and type IV collagen, and the intermediate filament proteins vimentin and prekeratin, in these three cell types using immunofluorescence techniques. Antisera to the basement membrane proteins stain the large epithelioid cells and the elongated cells, but do not stain the small cuboidal cells. Polyclonal antiserum to keratin stains all the small cuboidal and large epithelioid cells, but only a small subpopulation of the elongated cells. However, a monoclonal antibody to keratin, LP34, stains only the large cuboidal and a proportion of the elongated cells. Vimentin antiserum fails to stain the small cuboidal cells but stains all the large epithelioid and elongated cells. In addition, peanut lectin, which binds only to ductal lining epithelial cells in the virgin rat mammary gland in vivo after their treatment with neuraminidase, binds to the small cuboidal cells after neuraminidase treatment but not to the other cell types. However, Griffonia simplicifolia agglutinin I, which specifically stains myoepithelial cells in vivo, binds to the large epithelioid and elongated cells but not to the small cuboidal cells. These results suggest that the small cuboidal cells are related to mammary ductal epithelial cells whereas the large epithelial and elongated cells have some characteristics of myoepithelial cells.

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Synthesis of basement membrane proteins by rat mammary epithelial cells

Developmental Biology ◽

10.1016/0012-1606(83)90328-7 ◽

1983 ◽

Vol 96 (1) ◽

pp. 269-275 ◽

Cited By ~ 31

Author(s):

E.Jane Ormerod ◽

Michael J. Warburton ◽

Christine Hughes ◽

Philip S. Rudland

Keyword(s):

Membrane Proteins ◽

Epithelial Cells ◽

Basement Membrane ◽

Mammary Epithelial Cells ◽

Mammary Epithelial ◽

Basement Membrane Proteins

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Distribution of myoepithelial cells and basement membrane proteins in the resting, pregnant, lactating, and involuting rat mammary gland.

Journal of Histochemistry & Cytochemistry ◽

10.1177/30.7.6179984 ◽

1982 ◽

Vol 30 (7) ◽

pp. 667-676 ◽

Cited By ~ 141

Author(s):

M J Warburton ◽

D Mitchell ◽

E J Ormerod ◽

P Rudland

Keyword(s):

Mammary Gland ◽

Membrane Proteins ◽

Epithelial Cells ◽

Connective Tissue ◽

Basement Membrane ◽

Myoepithelial Cells ◽

Type I ◽

Continuous Layer ◽

Basement Membrane Proteins ◽

Rat Mammary Gland

Using antisera to specific proteins, the localization of the rat mammary parenchymal cells (both epithelial and myoepithelial), the basement membrane, and connective tissue components has been studied during the four physiological stages of the adult rat mammary gland, viz. resting, pregnant, lactating, and involuting glands. Antisera to myosin and prekeratin were used to localize myoepithelial cells, antisera to rat milk fat globule membrane for epithelial cells, antisera to laminin and type IV collagen to delineate the basement membrane and antisera to type I collagen and fibronectin as markers for connective tissue. In the resting, virgin mammary gland, myoepithelial cells appear to form a continuous layer around the epithelial cells and are in turn surrounded by a continuous basement membrane. Antiserum to fibronectin does not delineate the basement membrane in the resting gland. The ductal system is surrounded by connective tissue. Only the basal or myoepithelial cells in the terminal end buds of neonatal animals demonstrate cytoplasmic staining for basement membrane proteins, indicating active synthesis of these proteins during this period. In the secretory alveoli of the lactating rat, the myoepithelial cells no longer appear to form a continuous layer beneath the epithelial cells and in many areas the epithelial cells appear to be in contact with the basement membrane. The basement membrane in the lactating gland is still continuous around the ducts and alveoli. In the lactating gland, fibronectin appears to be located in the basement membrane region in addition to being a component of the stroma. During involution, the alveoli collapse, and appear to be in a state of dissolution. The basement membrane is thicker and is occasionally incomplete, as also are the basket-like myoepithelial structures. Basement membrane components can also be demonstrated throughout the collapsed alveoli.

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