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A novel arrangement of the 18S and 28S sequences in a repeating unit of drosophila melanogaster rDNA

Glover, David M. and Hogness, David S. (1977) A novel arrangement of the 18S and 28S sequences in a repeating unit of drosophila melanogaster rDNA. Cell, 10 (2). pp. 167-176. ISSN 0092-8674. doi:10.1016/0092-8674(77)90212-4.

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The sequences corresponding to the 18S and 28S rRNAs have been mapped within a cloned 17 kilobase (kb) fragment formed by Eco R1 cleavage of Drosophila melanogaster rDNA. This fragment, Dm103, represents the longer of two major types of repeating units that are present in the rDNA of this fly, and was cloned as a hybrid plasmid, pDm103, consisting of Dm103 inserted at the Eco R1 site of the pSC101 vector (Glover et al., 1975). Mapping of the 18S and 28S rDNA in Dm103 was accomplished by quantitative determination of the amount of these rDNAs in each member of an ordered set of restriction fragments obtained by Hind III and Eco R1 cleavage of pDm103. The amounts of 18S and 28S rDNAs were determined by hybridization of the rRNAs to fragments that were purified by cloning, and an unambiguous order of the fragments within pDm103 was established by heteroduplex mapping and from the stoichiometry of the fragment lengths. The resulting map revealed that the 4 kb of 28S rDNA within the long repeating unit represented by Dm103 is divided into two blocks that are separated by 5.4 kb of DNA of unknown function. It is this unusual arrangement of the 28S rDNA that distinguishes the long repeating units (17 kb) from the short units (11.5 kb), whose 4 kb of 28S rDNA is confined to a single block, as is shown in the accompanying paper ((White and Hogness, 1977)). The remainder of the DNA in this long unit appears to be typically arranged, with the 2 kb of 18S rDNA confined to a single block that is separated by about 1 kb from the closest block of 28S rDNA.

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Glover, David M.0000-0003-0956-0103
Additional Information:© 1977 MIT. Received 13 September 1976, Revised 22 October 1976. This work was supported by research grants from the NSF and the NIH. D.M.G. was a Damon Runyon fellow.
Funding AgencyGrant Number
Damon Runyon Cancer Research FoundationUNSPECIFIED
Issue or Number:2
Record Number:CaltechAUTHORS:20200806-163116690
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Official Citation:David M. Glover, David S. Hogness, A novel arrangement of the 18S and 28S sequences in a repeating unit of drosophila melanogaster rDNA, Cell, Volume 10, Issue 2, 1977, Pages 167-176, ISSN 0092-8674,
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104798
Deposited By: George Porter
Deposited On:10 Aug 2020 17:43
Last Modified:16 Nov 2021 18:35

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