Abstract
The structure of lipid-depleted retinal rod photoreceptor membranes was studied by means of electron microscopy. Aldehyde-fixed retinas were exhaustively extracted with acetone, chloroform-methanol, and acidified chloroform-methanol. The effect of prefixation on the extractability of lipids was evaluated by means of thin-layer chromatography and fatty acid analysis. Prefixation with glutaraldehyde rendered 38% of the phospholipids unextractable, while only 7% were unextractable after formaldehyde fixation. Embedding the retina in a lipid-retaining, polymerizable glutaraldehyde-urea mixture allows a comparison of the interaction of OsO4 with lipid-depleted membranes and rod disk membranes which contain all their lipids. A decrease in electron density and a deterioration of membrane fine structure in lipid-depleted tissue are correlated with the extent of lipid extraction. These observations are indicative of the role of the lipid bilayer in the ultrastructural visualization of membrane structure with OsO4. Negatively stained thin sections of extracted tissue reveal substructures in the lipid-depleted rod membranes. These substructures are probably the opsin molecules which are the major protein component of retinal rod photoreceptor membranes.
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Selected References
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- Anderson R. E., Feldman L. S., Feldman G. L. Lipids of ocular tissues. II. The phospholipids of mature bovine and rabbit whole retina. Biochim Biophys Acta. 1970 Mar 10;202(2):367–373. [PubMed] [Google Scholar]
- Anderson R. E., Maude M. B., Feldman G. L. Lipids of ocular tissues. I. The phospholipids of mature rabbit and bovine lens. Biochim Biophys Acta. 1969 Oct 28;187(3):345–353. [PubMed] [Google Scholar]
- Borovjagin V. L., Ivanina T. A. An ultrastructural study of the frog retinal rod photreceptor membranes phagocyted by pigment epithelium cells after aldehyde fixations and organic solvents treatments. Vision Res. 1973 Apr;13(4):753–757. doi: 10.1016/0042-6989(73)90039-4. [DOI] [PubMed] [Google Scholar]
- Bownds D., Gordon-Walker A., Gaide-Huguenin A. C., Robinson W. Characterization and analysis of frog photoreceptor membranes. J Gen Physiol. 1971 Sep;58(3):225–237. doi: 10.1085/jgp.58.3.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chapman D., Fluck D. J. Physical studies of phospholipids. 3. Electron microscope studies of some pure fully saturated 2,3-diacyl-DL-phosphatidyl-ethanolamines and phosphatidyl-cholines. J Cell Biol. 1966 Jul;30(1):1–11. doi: 10.1083/jcb.30.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eichberg J., Hess H. H. The lipid composition of frog retinal rod outer segments. Experientia. 1967 Dec 15;23(12):993–994. doi: 10.1007/BF02136402. [DOI] [PubMed] [Google Scholar]
- Falk G., Fatt P. Distinctive properties of the lamellar and disk-edge structures of the rod outer segment. J Ultrastruct Res. 1969 Jul;28(1):41–60. doi: 10.1016/s0022-5320(69)90005-7. [DOI] [PubMed] [Google Scholar]
- Fleischer S., Fleischer B., Stoeckenius W. Fine structure of lipid-depleted mitochondria. J Cell Biol. 1967 Jan;32(1):193–208. doi: 10.1083/jcb.32.1.193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gigg R., Payne S. The reaction of glutaraldehyde with tissue lipids. Chem Phys Lipids. 1969 Sep;3(3):292–295. doi: 10.1016/0009-3084(69)90021-8. [DOI] [PubMed] [Google Scholar]
- Godfrey A. J. A study of the ultrastructure of visual cell outer segment membranes. J Ultrastruct Res. 1973 May;43(3):228–246. doi: 10.1016/s0022-5320(73)80035-8. [DOI] [PubMed] [Google Scholar]
- Hall M. O., Bok D., Bacharach A. D. Biosynthesis and assembly of the rod outer segment membrane system. Formation and fate of visual pigment in the frog retina. J Mol Biol. 1969 Oct 28;45(2):397–406. doi: 10.1016/0022-2836(69)90114-4. [DOI] [PubMed] [Google Scholar]
- Hirosawa K. A preliminary note on the fine structure of the chloroform-methanol treated outer segment of frog retina. Arch Histol Jpn. 1971 Oct;33(4):341–349. doi: 10.1679/aohc1950.33.341. [DOI] [PubMed] [Google Scholar]
- Korn E. D., Weisman R. A. I. Loss of lipids during preparation of amoebae for electron microscopy. Biochim Biophys Acta. 1966 Apr 4;116(2):309–316. doi: 10.1016/0005-2760(66)90013-0. [DOI] [PubMed] [Google Scholar]
- LUFT J. H. Improvements in epoxy resin embedding methods. J Biophys Biochem Cytol. 1961 Feb;9:409–414. doi: 10.1083/jcb.9.2.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MORRISON W. R., SMITH L. M. PREPARATION OF FATTY ACID METHYL ESTERS AND DIMETHYLACETALS FROM LIPIDS WITH BORON FLUORIDE--METHANOL. J Lipid Res. 1964 Oct;5:600–608. [PubMed] [Google Scholar]
- Mason W. T., Fager R. S., Abrahamson E. W. Lipid and fatty acid composition of frog photoreceptor outer segments. Biochemistry. 1973 May 22;12(11):2147–2150. doi: 10.1021/bi00735a021. [DOI] [PubMed] [Google Scholar]
- Napolitano L., Lebaron F., Scaletti J. Preservation of myelin lamellar structure in the absence of lipid. A correlated chemical and morphological study. J Cell Biol. 1967 Sep;34(3):817–826. doi: 10.1083/jcb.34.3.817. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nir I., Pease D. C. Chloroplast organization and the ultrastructural localization of photosystems I and II. J Ultrastruct Res. 1973 Mar;42(5):534–550. doi: 10.1016/s0022-5320(73)80025-5. [DOI] [PubMed] [Google Scholar]
- Pease D. C., Peterson R. G. Polymerizable glutaraldehyde-urea mixtures as polar, water-containing embedding media. J Ultrastruct Res. 1972 Oct;41(1):133–159. doi: 10.1016/s0022-5320(72)90043-3. [DOI] [PubMed] [Google Scholar]
- Peterson R. G., Pease D. C. Myelin embedded in polymerized glutaraldehyde-urea. J Ultrastruct Res. 1972 Oct;41(1):115–132. doi: 10.1016/s0022-5320(72)90042-1. [DOI] [PubMed] [Google Scholar]
- Rouser G., Siakotos A. N., Fleischer S. Quantitative analysis of phospholipids by thin-layer chromatography and phosphorus analysis of spots. Lipids. 1966 Jan;1(1):85–86. doi: 10.1007/BF02668129. [DOI] [PubMed] [Google Scholar]