Investigation of chromatin folding patterns by atomic force microscopy

ZHANG Yi，

OUYANG Zhenqian，

HU Jun，

CHEN Shengfu，

LI Minqian，

ZHAO Hui，

QIAN Ruolan

Nuclear Science and Techniques

Vol.10, No.2

pp.96-99

Published in print 01 Mar 1999

31200

The chromatin folding patterns in air and liquid were studied by atomic force microscopy (AFM). A gentle water-air interface method was adopted to spread chromatin from interphase nucleus of chicken erythrocyte. The chromatin was absorbed on APS-mica surface and studied with AFM. Beads-on-a-string were observed and many higher-order structures such as superbeads with dimensions 40~60 nm in diameter and 4~7 nm in height were found to string together to make chromatin fibers. When sample spreading and absorbing time were shortened, higher-order chromatin fibers with 60~120 nm in width were observed in air as well as under water environment. These chromatin structures may reflect chromatin folding patterns in the living cells.

Chromatin folding patternsAtomic force microscopyChicken erythrocytes

References

Olins A L. Olins D E. Science, 1974, 183: 330~332

Finch J T. Noll M, Kornberg R D. Proc Natl Acad Sci USA, 1975. 72: 3320

Ouder P M, Gross-belland , Chambon P. Cell, 1975; 4: 281

Brasch K. Exp Cell Res, 1976, 5: 396

Belmont A S, Braunfeld M B, Sedat J W et al. Chromosoma, 1989, 98: 129~143

Belmont A S, Bruce K. J Cell Biol, 1994, 127, 2: 287~302

Finch J F, Klug A. Natl Acad Sci USA, 1976, 73, 6: 1897~1901

Woodcock C L F, L-L Y Frado, J B Rat-tner. J cell Biol, 1984, 99: 42~52

Horowitz R A, Agard D A, Sedat J W et al. J Cell Biol, 1994, 125, 1: 1~10

Thoma F, Koller T H, Klug A. J cell Biol, 1979, 83: 403~427

Zentgraf H, Frake W. J Cell Biol, 1984, 999: 272~286

Boy de la Tour E, Laemmli U K. Cell, 1988, 55: 937~944

James R. Paulson, U K Laemmli. Cell, 1977, 12: 817~828

Rattner J B, Lin C C. Cell, 1985, 42: 291~296

Binnig G, Quate C F, Gerber C. Phys Rev Lett, 1986, 56: 930~933

Allen M J, C Lee, J D Lee et al. Chromosoma. 1993, 102(9): 623~630

Allen M J, Dong X F, O'Neill T E et al. Biochemistry, 1993, 32: 8390~8396

Sanfold H L, Guoliang Y, C Robert et al. Proc Natl Acad Sci USA, 1994, 91: 11621~11625

Martin L D, Vesenka J P. Henderson E et al. Biochemistry, 1995, 34: 4610~4616

Qian R L, Liu Z X, Zhou M Y et al. Cell Research, 1997, 7: 143~150

Vesenka J, Hansma H, Siegerist C et al. SPIE Proc, 1992, 1639: 127

Fritzsche W, Schaper A, Jovin T V. Scanning, 1995, 17: 148~155

Zhu J D, Sun X P, Wang F. Biochim Bio-phys Acta, 1991, 1089(2): 158~165

Hanswalter Zentgraf, Ulrike Muller, Werner W Franke. Euro J Cell Biol, 1980, 23: 171~188