Association of DNA with nuclear matrix in in vitro assembled nuclei induced by rDNA from Tetrahymena shanghaiensis in Xenopus egg extracts.
The nuclei assembled from exogenous DNA or chromatin in egg extracts resemble their in vivo counterparts in many aspects. However, the distribution pattern of DNA in these nuclei remains unknown. We introduced rDNA from the macronuclei of Tetrahymena into Xenopus cell-free extracts to examine the association of specific DNA sequences with nuclear matrix (NM) in the nuclei assembled in vitro. Our previous works showed the 5'NTS (non-transcription sequences) of the rDNA specifically bind to the NM system in the macronuclei. We show now the rDNA could induce chromatin assembly and nuclear formation in Xenopus cell-free system. When we extracted the NM system and compared the binding affinity of different regions of rDNA with the NM system, we found that the 5'NTS still hold their binding affinity with insoluble structure of the assembled nuclei in the extracts of Xenopus eggs.
Chen
Y
Y
Department of Cell Biology and Genetics, College of Life Sciences, Peking University, Beijing.
Zhang
B
B
Li
X F
XF
Zhai
Z H
ZH
D000818:Animals; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002474:Cell-Free System; D016054:DNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D004275:DNA, Ribosomal / Q000235:genetics / Q000378:metabolism*; D015530:Nuclear Matrix / Q000378:metabolism; D009865:Oocytes; D012045:Regulatory Sequences, Nucleic Acid; D013768:Tetrahymena; D014981:Xenopus
D002457:Cell Extracts; D016054:DNA, Protozoan; D004275:DNA, Ribosomal