Diseases, Conditions, Syndromes

New proof of link between obesity and disease

The University of South Australia's Australian Centre for Precision Health researchers examined links between body mass index (BMI) and more than 925 diseases in 337536 UK volunteers, confirming the link between obesity and ...

Genetics

Researchers report the function of reverse-twisting DNA

Normally, the two strands of the DNA double helix wind around each other in a right-handed spiral. However, there is another conformation called Z-DNA in which the strands twist to the left. The function of Z-DNA has remained ...

Genetics

Does genetic testing pose psychosocial risks?

For the last quarter century, researchers have been asking whether genetic information might have negative psychosocial effects. Anxiety, depression, disrupted relationships, and heightened stigmatization have all been posited ...

Genetics

A noncoding RNA may play an important role in memory formation

You could call this a neat discovery. Researchers at the University of Alabama at Birmingham have found that a tissue-specific, non-coding RNA called NEAT1 has a major, previously undescribed role in memory formation. The ...

page 1 from 23

DNA sequence

A DNA sequence or genetic sequence is a succession of letters representing the primary structure of a real or hypothetical DNA molecule or strand, with the capacity to carry information as described by the central dogma of molecular biology.

The possible letters are A, C, G, and T, representing the four nucleotide bases of a DNA strand — adenine, cytosine, guanine, thymine — covalently linked to a phosphodiester backbone. In the typical case, the sequences are printed abutting one another without gaps, as in the sequence AAAGTCTGAC, read left to right in the 5' to 3' direction. Short sequences of nucleotides are referred to as oligonucleotides and are used in a range of laboratory applications in molecular biology. With regard to biological function, a DNA sequence may be considered sense or antisense, and either coding or noncoding. DNA sequences can also contain "junk DNA."

Sequences can be derived from the biological raw material through a process called DNA sequencing.

In some special cases, letters besides A, T, C, and G are present in a sequence. These letters represent ambiguity. Of all the molecules sampled, there is more than one kind of nucleotide at that position. The rules of the International Union of Pure and Applied Chemistry (IUPAC) are as follows:

This text uses material from Wikipedia, licensed under CC BY-SA