W-heterochromatin of chicken; its unusual DNA components, late replication, and chromatin structure.
About 65% of DNA in the chicken W chromosome has been shown to consist of XhoI and EcoRI family repetitive sequences. These sequences showed remarkable delay in the electrophoretic mobility at low temperature on a polyacrylamide gel. Three dimensional structures of the 0.7-kb XhoI and the 1.2-kb EcoRI family repeating units were estimated to be irregular solenoids using a computer program based on wedge angles of all the 16 dinucleotide steps. Fluorescence in situ hybridization demonstrated that these two family sequences were localized in a major heterochromatic body in an interphase nucleus. Incorporation of bromodeoxyuridine into the W chromosome in the synchronous culture of MSB-1 cells occurred about 1 h later than the peak of S phase. The chromatin structure formed along XhoI and EcoRI family sequences was suggested to be different from the total chromatin or chromatin containing the beta-actin gene sequence in that the linker DNA lengths of the former were significantly longer. Fractionation of the HaeIII-digested MSB-1 nuclei yielded a chromatin fraction in which XhoI family sequences were partially enriched. Several DNA-binding proteins showing higher affinity for the XhoI family sequence were present in this fraction.
Suka
N
N
Department of Applied Biological Science, Faculty of Agriculture, Tohoku University, Sendai, Japan.
Shinohara
Y
Y
Saitoh
Y
Y
Saitoh
H
H
Ohtomo
K
K
Harata
M
M
Shpigelman
E
E
Mizuno
S
S
D000199:Actins / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002478:Cells, Cultured; D002645:Chickens / Q000235:genetics*; D004247:DNA / Q000032:analysis*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D005796:Genes; D006570:Heterochromatin / Q000378:metabolism / Q000648:ultrastructure*; D017404:In Situ Hybridization, Fluorescence; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000648:ultrastructure; D012091:Repetitive Sequences, Nucleic Acid; D012730:Sex Chromosomes / Q000648:ultrastructure*
D000199:Actins; D004268:DNA-Binding Proteins; D006570:Heterochromatin; D009707:Nucleosomes; D004247:DNA