scholarly journals Ultrastructural localization of fibronectin to different anatomic structures of human skin.

1984 ◽  
Vol 32 (3) ◽  
pp. 315-321 ◽  
Author(s):  
R Fleischmajer ◽  
R Timpl

Fibronectin was localized in fetal and adult human skin with affinity-purified antibodies, using a ferritin staining technique. The most common observation was a close association of this fibronectin with thin and thick cross-striated fibrils containing collagens types I and III. Deposits of fibronectin occurred in discrete spots, with some regular distribution, in agreement with a major binding site for this protein on collagen. Fibronectin was also detectable at the periphery of elastic fibrils and in amorphous, non-fibrillar regions of skin. The latter pattern included a close pericellular localization, indicating interactions between fibronectin and plasma membranes. Discrete deposits of fibronectin were also found on the lamina lucida of the basement membrane of the dermal-epidermal junction and around small blood vessels. This widespread distribution of fibronectin suggests that it has a multitude of biologic functions in situ.

2002 ◽  
Vol 118 (1) ◽  
pp. 180-184 ◽  
Author(s):  
Chunyan Zhao ◽  
Kari Hemminki ◽  
Erna Snellman ◽  
Christer T. Jansen
Keyword(s):  

1959 ◽  
Vol 37 (1) ◽  
pp. 65-72 ◽  
Author(s):  
G. Setterfield ◽  
H. Stern ◽  
F. B. Johnston

To provide a basis for relating biochemical findings on isolated cell fractions to cytological structure in situ, embryos of pea and wheat were fixed with osmic acid, sectioned, and observed in phase-contrast and electron microscopes. The nuclei of all cells were similar, showing nuclear membranes, chromosomes, and prominent nucleoli. The cytoplasm contained highly developed structure which presumably reflected the incipient growth condition of the cells. Several cytoplasmic components were common to both embryos: small dense granules, endoplasmic reticulum, mitochondria, presumed proplastids, amyloplasts, irregular bodies, plasma membranes, and plasmodesmata. The small dense granules, presumably ribonucleoprotein particles, occurred profusely, both free and in association with extensively developed endoplasmic reticulum. These particles are probably responsible for the microsomal fractions obtainable from embryos and seedlings. The mitochondria were usually relatively small (0.25−0.5 μ diameter) although groups of very long (5 μ) ones were occasionally found. Bodies resembling mitochondria in size and shape, but lacking cristae, were present and represent either immature mitochondria or proplastids. Reserve material occurred as starch in structurally complex amyloplasts and possibly as protein in the irregular bodies. In addition to these structures cells of the wheat embryos remote from the meristems contained prominent cytoplasmic bodies classified as "dense" and "thick-walled". The dense bodies probably represent stored lipids while the significance of the thick-walled bodies, which showed a variety of forms, is unknown.


2004 ◽  
Vol 166 (4) ◽  
pp. 559-570 ◽  
Author(s):  
Shin-ichiro Kitajiri ◽  
Kanehisa Fukumoto ◽  
Masaki Hata ◽  
Hiroyuki Sasaki ◽  
Tatsuya Katsuno ◽  
...  

Ezrin/radixin/moesin (ERM) proteins cross-link actin filaments to plasma membranes to integrate the function of cortical layers, especially microvilli. We found that in cochlear and vestibular sensory hair cells of adult wild-type mice, radixin was specifically enriched in stereocilia, specially developed giant microvilli, and that radixin-deficient (Rdx−/−) adult mice exhibited deafness but no obvious vestibular dysfunction. Before the age of hearing onset (∼2 wk), in the cochlea and vestibule of Rdx−/− mice, stereocilia developed normally in which ezrin was concentrated. As these Rdx−/− mice grew, ezrin-based cochlear stereocilia progressively degenerated, causing deafness, whereas ezrin-based vestibular stereocilia were maintained normally in adult Rdx−/− mice. Thus, we concluded that radixin is indispensable for the hearing ability in mice through the maintenance of cochlear stereocilia, once developed. In Rdx−/− mice, ezrin appeared to compensate for radixin deficiency in terms of the development of cochlear stereocilia and the development/maintenance of vestibular stereocilia. These findings indicated the existence of complicate functional redundancy in situ among ERM proteins.


2014 ◽  
Vol 1840 (8) ◽  
pp. 2635-2642 ◽  
Author(s):  
Andreas A. Armatas ◽  
Harris Pratsinis ◽  
Eleni Mavrogonatou ◽  
Maria T. Angelopoulou ◽  
Anastasios Kouroumalis ◽  
...  

1994 ◽  
Vol 107 (2) ◽  
pp. 463-475 ◽  
Author(s):  
M.C. Azum-Gelade ◽  
J. Noaillac-Depeyre ◽  
M. Caizergues-Ferrer ◽  
N. Gas

The distribution of the U3 small nuclear RNA during the cell cycle of the CHO cell line was studied by in situ hybridization using digoxigenin-labelled oligonucleotide probes. The location of the hybrids by immunofluorescence microscopy and at the ultrastructural level was correlated with the distribution of two nucleolar proteins, nucleolin and fibrillarin. The U3 snRNA molecules persist throughout mitosis in close association with the nucleolar remnant. U3 snRNA is present in the prenucleolar bodies (PNBs) and could participate in nucleologenesis in association with several nucleolar proteins such as nucleolin and fibrillarin. The interaction of U3 snRNP with the 5′ external spacer of pre-RNA newly synthesized by active NORs is proposed to be the promoting event of nucleologenesis.


2005 ◽  
Vol 36 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Wun-Ju Shieh ◽  
Cheng-Hsiang Hsiao ◽  
Christopher D. Paddock ◽  
Jeannette Guarner ◽  
Cynthia S. Goldsmith ◽  
...  

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