title: DNA degradation in terminally differentiating lens fiber cells from chick embryos.
abstract: During the terminal differentiation of lens fiber cells, nuclear DNA is known to accumulate free 3'-OH ends and is progressively lost from the nucleus. Toward the end of this process, nuclei undergo pycnosis and disappear. The size of the DNA in the epithelia and in early and late stages of fiber cell development was examined by electrophoresis on nondenaturing agarose/polyacrylamide gels. Low molecular weight DNA of discrete sizes appears only at the final stages of nuclear degeneration in central fiber cells and persists after the disappearance of the nuclei. These low molecular weight DNA fragments appear as multiples of a monomeric unit and are similar to the fragments produced by the digestion of epithelial cell nuclei by micrococcal nuclease. The data indicate that in lens fiber nuclei the double-strand breaks in vivo affect the chromatin during nuclear degeneration, and the data suggest that the DNA of these cells is organized into chromatin composed of discrete subunits.
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D002642:Chick Embryo; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D007908:Lens, Crystalline / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D008836:Micrococcal Nuclease / Q000378:metabolism; D008970:Molecular Weight
chemical_list: D002843:Chromatin; D004247:DNA; D008836:Micrococcal Nuclease
references.citation: FEBS Lett. 1976 Dec 31;72(2):271-4
references.pmid: 16386038
references.citation: Proc Natl Acad Sci U S A. 1977 Jan;74(1):79-83
references.pmid: 319461
references.citation: J Mol Biol. 1977 Feb 15;110(1):119-46
references.pmid: 845942
references.citation: Exp Cell Res. 1972 Dec;75(2):307-13
references.pmid: 4566303
references.citation: Dev Biol. 1973 Oct;34(2):334-45
references.pmid: 4596973
references.citation: Eur J Biochem. 1976 Jan 2;61(1):119-38
references.pmid: 173549
references.citation: Eur J Biochem. 1976 Jan 2;61(1):101-17
references.pmid: 173548
references.citation: Biochem Biophys Res Commun. 1973 May 15;52(2):504-10
references.pmid: 4711166
references.citation: Exp Cell Res. 1970 Jan;59(1):43-56
references.pmid: 4915191
references.citation: Exp Cell Res. 1970 Oct;62(2):421-32
references.pmid: 4924612
references.citation: Biochemistry. 1968 Feb;7(2):668-74
references.pmid: 4868544
references.citation: Proc Natl Acad Sci U S A. 1976 Feb;73(2):505-9
references.pmid: 1061151
references.citation: Nucleic Acids Res. 1976 Apr;3(4):1101-10
references.pmid: 1272805
references.citation: Nucleic Acids Res. 1976 Jan;3(1):117-27
references.pmid: 1250693
references.citation: Biochemistry. 1975 Jul;14(13):2915-20
references.pmid: 1148184
references.citation: Exp Cell Res. 1971 Feb;64(2):473-6
references.pmid: 5100760
references.citation: Exp Eye Res. 1970 Jan;9(1):144-51
references.pmid: 5417906
references.citation: Exp Cell Res. 1969 Jul;56(1):105-13
references.pmid: 5793042
references.citation: Dev Biol. 1968 May;17(5):544-61
references.pmid: 5658458