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Evolutionary divergence and length of repetitive sequences in sea urchin DNA

Britten, Roy J. and Graham, Dale E. and Eden, Francine C. and Painchaud, Denise M. and Davidson, Eric H. (1976) Evolutionary divergence and length of repetitive sequences in sea urchin DNA. Journal of Molecular Evolution, 9 (1). pp. 1-23. ISSN 0022-2844. doi:10.1007/BF01796119.

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The organization of repetitive and single copy DNA sequences in sea urchin DNA has been examined with the single strand specific nuclease Sl fromAspergillus. Conditions and levels of enzyme were established so that single strand DNA was effectively digested while reassociated divergent repetitive duplexes remained enzyme resistant. About 25% of sea urchin DNA reassociates with repetitive kinetics to form Sl resistant duplexes of two distinct size classes derived from long and short repetitive sequences in the sea urchin genome. Fragments 2,000 nucleotides long were reassociated to Cot 20 and subjected to controlled digestion with Sl nuclease. About half of the resistant duplexes (13% of the DNA) are short, with a mode size of about 300 nucleotide pairs. This class exhibits significant sequence divergence, and principally consists of repetitive sequences which were interspersed with single copy sequences. About one-third of the long duplexes (4% of the DNA) are reduced in size after extensive Sl nuclease digestion to about 300 nucleotide pairs. About two-thirds of the long resistant duplexes (8% of the DNA) remains long after extensive SI nuclease digestion. These long reassociated duplexes are precisely base paired. The short duplexes are imprecisely paired with a melting temperature about 9°C below that of precisely paired duplexes of the same length. The relationship between length of repetitive duplex and precision of repetition is confirmed by an independent method and has been observed in the DNA of a number of species over a wide phylogenetic area.

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Additional Information:© 1976 Springer. Received July 26, 1976. This research was supported by grants from the National Science Foundation. D.E.G. was supported by fellowship grants from the Damon Runyon-Walter Winchell Cancer Fund and the Carnegie Institution of Washington, and F.C.E. was supported by a fellowship grant from the american Cancer Society.
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Damon Runyon-Walter Winchell Cancer FundUNSPECIFIED
Carnegie Institution of WashingtonUNSPECIFIED
American Cancer SocietyUNSPECIFIED
Subject Keywords:Evolution; Repetitive DNA; SI Nuclease; Sequence Organization
Issue or Number:1
Record Number:CaltechAUTHORS:20151216-172822557
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Official Citation:Britten, R.J., Graham, D.E., Eden, F.C. et al. Evolutionary divergence and length of repetitive sequences in sea urchin DNA. J Mol Evol 9, 1–23 (1976).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:63014
Deposited By: George Porter
Deposited On:29 Jan 2016 15:43
Last Modified:10 Nov 2021 23:10

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