Seminiferous tubule basement membrane. Composition and organization of type IV collagen chains, and the linkage of alpha3(IV) and alpha5(IV) chains.

Seminiferous tubule basement membrane (STBM) plays an important role in spermatogenesis. In the present study, the composition and structural organization of type IV collagen of bovine STBM was investigated. STBM was found to be composed of all six alpha-chains of type IV collagen based upon immunocytochemical and biochemical analysis.

Goodpasture syndrome: selective removal of anti-alpha 3 (IV) collagen autoantibodies. A potential therapeutic alternative to plasmapheresis.

Anti-alpha 3(IV) collagen autoantibodies have been implicated in the pathogenesis of Goodpasture syndrome, an autoimmune disorder causing glomerulonephritis and pulmonary hemorrhage. Currently treatment involves removal of the entire IgG fraction of plasma by plasmapheresis or adsorption to protein A. The present study shows that the anti-alpha 3(IV)NC1 autoantibodies can be removed from plasma specifically and quantitatively by affinity chromatography utilizing either alpha 3 NC1 domain of bovine type IV collagen or recombinant alpha 3 NC1 domain of human type IV collagen immobilized to agarose beads.

Developmental changes in seminiferous tubule extracellular matrix components of the mouse testis: alpha 3(IV) collagen chain expressed at the initiation of spermatogenesis.

The temporal expression of type IV collagen, laminin, and entactin in the basal laminae of the seminiferous tubule during development of the mouse testis was determined. Northern blot analysis was used to examine changes in testicular mRNA for alpha 1-alpha 5 type IV collagen (IV) chains in mice ranging in age from newborn to adult (60 days). Levels for mRNA alpha 1(IV) and alpha 2(IV) chains were highest in newborns through Day 5 and remained elevated through Day 10, but then sharply declined to adult values by Day 30.

Structure and function of the photoreceptor stentorins in Stentor coeruleus. I. Partial characterization of the photoreceptor organelle and stentorins.

The unicellular ciliary protozoan, Stentor coeruleus, exhibits photophobic and phototactic responses to visible light stimuli. The pigment granule contains the photoreceptor chromoproteins (stentorins). Stentorin localized in the pigment granules of the cell serves as the primary photoreceptor for the photophobic and phototactic responses in this organism.