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Interspersed sequence organization and developmental representation of cloned poly(A) RNAs from sea urchin eggs

Posakony, James W. and Flytzanis, Constantin N. and Britten, Roy J. and Davidson, Eric H. (1983) Interspersed sequence organization and developmental representation of cloned poly(A) RNAs from sea urchin eggs. Journal of Molecular Biology, 167 (2). pp. 361-389. ISSN 0022-2836. doi:10.1016/S0022-2836(83)80340-4.

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A random primed complementary DNA (cDNA) clone library constructed from total maternal poly(A) RNA of sea urchin eggs was screened with two cloned genomic repetitive sequence probes. Sets of cDNA clones reacting with each of these repetitive sequences were recovered. Most of the cloned transcripts included both single copy and repeat sequence elements. Except for the shared repeat sequence element, both the repetitive and single copy regions of the members of each set of clones failed to crossreact. Single copy probes linked to the repeats on the cloned maternal RNAs are represented in an asymmetric manner. It follows that many different genomic members of a given dispersed repeat sequence family are represented in the maternal RNA. RNA gel blots carried out with several repeat probes display about 10 to 20 prominent maternal poly(A) RNAs containing transcripts of each repetitive sequence family. The interspersed maternal transcripts are 3000 to 15,000 bases in length. Maternal transcripts reacting with single copy probes derived from the cloned cDNAs persist during embryonic development, and in some cases appear to be augmented by similar, newly synthesized embryo transcripts. Two examples were found in which additional transcripts of different length appear at specific developmental stages. The transcribed single copy regions are highly polymorphic in the genomes of different individual sea urchins, and comparisons of closely related sea urchin species showed that both the prevalence and length of specific maternal transcripts change rapidly during evolution. Nucleotide sequences of two homologous repeat elements occurring on different cloned transcripts displayed translation stop codons in every possible reading frame. These repeat sequences display structural features suggesting that there has been evolutionary transposition into transcription units active during oogenesis. The repeat elements and their flanking single copy regions reside either in very long 3′ or 5′-terminal sequences, or in unprocessed intervening sequences in the maternal poly(A) RNA. These findings lead us to the proposal that the majority of the cytoplasmic poly(A) RNA in echinoderm eggs and early embryos is similar in form to RNAs that occur in the nucleus rather than to the messenger RNA of later cells.

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Additional Information:© 1983 Elsevier Ltd. Received 25 August 1982, and in revised form 9 February 1983. We are pleased to acknowledge the conscientious technical assistance of Ronald C. Wek in sequencing in this work. We thank Mr Gary Mockli, who was supported by a Summer Undergraduate Research fellowship, for his able assistance in mapping the cDNA clones. One of us (J.W.P.) was supported in the early phases of this work by a National Institutes of Health training grant (GM-07616). The research was supported by National Science Foundation grant PCM-8004072. We gratefully acknowledge the critical suggestions of Dr Norman Davidson and Dr Ellen Rothenberg of this Institute.
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Caltech Summer Undergraduate Research Fellowship (SURF)UNSPECIFIED
NIH Predoctoral FellowshipGM-07616
Issue or Number:2
Record Number:CaltechAUTHORS:20160513-111340734
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Official Citation:James W. Posakony, Constantin N. Flytzanis, Roy J. Britten, Eric H. Davidson, Interspersed sequence organization and developmental representation of cloned poly(A) RNAs from sea urchin eggs, Journal of Molecular Biology, Volume 167, Issue 2, 1983, Pages 361-389, ISSN 0022-2836, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67076
Deposited By: Tony Diaz
Deposited On:13 May 2016 18:41
Last Modified:11 Nov 2021 00:26

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