NUMBER AND STRUCTURE OF BALBIANI RING 75-S RNA-TRANSCRIPTION UNITS IN CHIRONOMUS TENTANS

被引:40
作者
WIESLANDER, L
机构
关键词
D O I
10.1016/0022-2836(79)90039-1
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The number and structure of the Balbiani ring (BR) 75 S RNA transcription units in Chironomus tentans have been studied in DNA-RNA hybridization experiments. Using DNA excess hybridization it was shown that BR 2 RNA is complementary to highly repetitive DNA sequences (4000 to 5000 times per haploid genome) as well as to sequences with a low degree of repetition (6 to 8 times). Available information indicates that BR 2 RNA represents growing RNA molecules from a single 75 S RNA transcription unit, and it is therefore concluded that the two types of sequences are present in one and the same 75 S RNA transcript. BR 1 RNA, known to consist of nascent 75 S RNA with different nucleotide sequence from that of BR 2 RNA, was also found to be complementary to highly repetitive DNA sequences (1300 to 1600 times) as well as to sequences with a low degree of repetition (13 to 16 times). Cellular 75 S RNA was analysed in order to determine the number of the corresponding BR transcription units. As demonstrated by in situ hybridization, cellular 75 S RNA consists of RNA generated in BR 1 and BR 2. The hybridization properties of cellular 75 S RNA with excess DNA were found to be in agreement with such a conclusion. The cellular 75 S RNA was used to titrate the amount of complementary DNA. A saturation level of 0.043% was reached, corresponding to between four and five 75 S RNA transcription units. Since the distribution of these units between BR 1 and BR 2 is not known, it is concluded that each BR may contain from one to four 75 S RNA transcription units per chromatid. The major part (60 to 75%) of each unit consists of highly repeated sequences and the rest consists of sequences present once or a few times per unit. The functional significance of the repeated structure of the 75 S RNA transcription units is discussed. © 1979.
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页码:347 / 367
页数:21
相关论文
共 69 条
[21]   BASE COMPOSITION OF NUCLEIC ACIDS IN CHROMOSOMES, PUFFS, NUCLEOLI, AND CYTOPLASM OF CHIRONOMUS SALIVARY GLAND CELLS [J].
EDSTROM, JE ;
BEERMANN, W .
JOURNAL OF CELL BIOLOGY, 1962, 14 (03) :371-&
[22]   BALBIANI RING RNA-CONTENT AND HALF-LIFE IN NUCLEUS AND CYTOPLASM OF CHIRONOMUS-TENTANS SALIVARY-GLAND CELLS [J].
EDSTROM, JE ;
LINDGREN, S ;
LONN, U ;
RYDLANDER, L .
CHROMOSOMA, 1978, 66 (01) :33-44
[23]   INHIBITION OF BALBIANI RING RNA-SYNTHESIS AT INITIATION LEVEL [J].
EGYHAZI, E .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1975, 72 (03) :947-950
[24]   TENTATIVE INITIATION INHIBITOR OF CHROMOSOMAL HETEROGENEOUS RNA-SYNTHESIS [J].
EGYHAZI, E .
JOURNAL OF MOLECULAR BIOLOGY, 1974, 84 (01) :173-183
[25]   DETERMINATION OF MULTIPLICITY OF SILK FIBROIN GENE AND DETECTION OF FIBROIN GENE-RELATED DNA IN GENOME OF BOMBYX-MORI [J].
GAGE, LP ;
MANNING, RF .
JOURNAL OF MOLECULAR BIOLOGY, 1976, 101 (03) :327-348
[26]   STUDIES ON NUCLEIC-ACID REASSOCIATION KINETICS - RETARDED RATE OF HYBRIDIZATION OF RNA WITH EXCESS DNA [J].
GALAU, GA ;
SMITH, MJ ;
BRITTEN, RJ ;
DAVIDSON, EH .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1977, 74 (06) :2306-2310
[27]   AN IMPROVED DIPHENYLAMINE METHOD FOR ESTIMATION OF DEOXYRIBONUCLEIC ACID [J].
GILES, KW ;
MYERS, A .
NATURE, 1965, 206 (4979) :93-&
[28]   CHROMOSOME PUFFS AND GENE-EXPRESSION IN POLYTENE CELLS [J].
GROSSBACH, U .
COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY, 1973, 38 :619-627
[29]   CHROMOSOME ACTIVITY AND BIOCHEMICAL CELL DIFFERENTIATION IN SALIVARY GLANDS OF CAMPTOCHIRONOMUS [J].
GROSSBACH, U .
CHROMOSOMA, 1969, 28 (02) :136-+
[30]  
GROSSBACH U, 1976, BIOCH DIFFERENTIATIO, P147