Biomaterial Database

Polypyrimidine sequences found in eukaryotic DNA have been conserved during evolution. 1976

N A Straus, and H C Birnboim

L-cell DNA contains an unexpectedly large amount of long pyrimidine tracts. Hydroxyapatite chromatography has been employed to show that these polypyrimidines hydridize extensively to the reiterated DNA of a large number of eukaryotes but fail to hybridize to prokaryotic DNA. This reaction is sequence specific and not the result of a special property of polypyrimidines since random 3H-labelled poly(dC-dT) shows poor hybridization to eukaryotic DNA. The hybrids formed by L-cell polypyrimidines and heterologous repeated sequences have a higher thermal stability than the corresponding hybrids of total repeated DNA indicating that sequences related to these polypyrimidines have been conserved during evolution. Furthermore, at least some of these tracts are transcribed because they are capable of reacting extensively with total cellular RNA. Although the function of these sequences is not yet known, the fact that they are widely conserved in evolution and also transcribed leads us to speculate that they play an an important role in eukaryotic cells.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007739	L Cells	A cultured line of C3H mouse FIBROBLASTS that do not adhere to one another and do not express CADHERINS.	Earle's Strain L Cells,L Cell Line,L Cells (Cell Line),L-Cell Line,L-Cells,L-Cells, Cell Line,L929 Cell Line,L929 Cells,NCTC Clone 929 Cells,NCTC Clone 929 of Strain L Cells,Strain L Cells,Cell Line L-Cell,Cell Line L-Cells,Cell Line, L,Cell Line, L929,Cell Lines, L,Cell, L,Cell, L (Cell Line),Cell, L929,Cell, Strain L,Cells, L,Cells, L (Cell Line),Cells, L929,Cells, Strain L,L Cell,L Cell (Cell Line),L Cell Lines,L Cell, Strain,L Cells, Cell Line,L Cells, Strain,L-Cell,L-Cell Lines,L-Cell, Cell Line,L929 Cell,Strain L Cell
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
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
D011089	Polydeoxyribonucleotides	A group of 13 or more deoxyribonucleotides in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.	Polydeoxyribonucleotide
D011743	Pyrimidines	A family of 6-membered heterocyclic compounds occurring in nature in a wide variety of forms. They include several nucleic acid constituents (CYTOSINE; THYMINE; and URACIL) and form the basic structure of the barbiturates.
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