Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 1978 | public
Journal Article

Characteristics of individual repetitive sequence families in the sea urchin genome studied with cloned repeats

Abstract

Cloned repetitive sequences from the S. purpuratus genome a few hundred to approximately 1000 nucleotides long were used to investigate the characteristics of individual repetitive sequence families. They were terminally labeled by the kinase procedure and reacted with sheared S. purpuratus DNA. Repetition frequencies were measured for 26 individual families and were found to vary from a few to several thousand copies per genome. Estimates of sequence divergence were made for 18 cloned repeat families by measuring thermal stability of the heteroduplexes formed between the genomic DNA and the cloned fragments, compared with that of the renatured cloned fragments. The difference was <4°C for three of the 18 families, and <10°C for 13 of the 18 families. These 13 repetitive sequence families lack any detectable highly divergent sequence relatives, and the results reported are shown not to change when the renaturation criterion is lowered below 55°C in 0.18 M Na^+. Five of the 18 cloned families displayed greater sequence divergence. The average sequence divergence of the total short repetitive sequence fraction of S. purpuratus DNA was found to match closely the average of the divergences of the cloned repeat sequences.

Additional Information

© 1978 MIT. Received February 28, 1978; revised May 1, 1978. This research was supported by a grant from the National Institute of General Medical Sciences. W.H.K. is the recipient of a Lievre Fellowship from the American Cancer Society, California Division, and T.L.T. is the recipient of an NIH postdoctoral fellowship. R.H.S. is a predoctoral fellow on an NIH training grant. The P2 facilities used in this work were equipped with the aid of funds from a Biomedical Research Support Grant. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023