Biomaterial Database

The evolution of repetitive DNA sequences in sea urchins. 1977

M M Harpold, and S P Craig

Molecular hybridization of nuclear DNAs has been employed to study the evolution of the repetitive DNA sequences in four species of sea urchin. The data show that relative to S. purpuratus there has been approximately 0.1% sequence divergence per million years in the repetitive DNA sequences of S. droebachiensis, S. franciscanus, and L. pictus. These results confirm that repetitive DNA sequences are strongly conserved during evolution. However, comparison of the extent of base pair mismatch in the repetitive DNA heteroduplexes formed at Cot 20 with those formed at Cot 200 during the hybridization of S. purpuratus and L. pictus DNAs reveals that highly repetitive sequences of sea urchins may diverge more rapidly than do the more moderately repetitive sequences.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009693	Nucleic Acid Hybridization	Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)	Genomic Hybridization,Acid Hybridization, Nucleic,Acid Hybridizations, Nucleic,Genomic Hybridizations,Hybridization, Genomic,Hybridization, Nucleic Acid,Hybridizations, Genomic,Hybridizations, Nucleic Acid,Nucleic Acid Hybridizations
D009695	Nucleic Acid Renaturation	The reformation of all, or part of, the native conformation of a nucleic acid molecule after the molecule has undergone denaturation.	Acid Renaturation, Nucleic,Acid Renaturations, Nucleic,Nucleic Acid Renaturations,Renaturation, Nucleic Acid,Renaturations, Nucleic Acid
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D005075	Biological Evolution	The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.	Evolution, Biological
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012617	Sea Urchins	Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.	Echinoidea,Sand-Dollar,Clypeasteroida,Sand Dollars,Clypeasteroidas,Dollar, Sand,Dollars, Sand,Echinoideas,Sand Dollar,Sand-Dollars,Sea Urchin,Urchin, Sea,Urchins, Sea
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures