Warning: imagejpeg(C:\Inetpub\vhosts\kidney.de\httpdocs\phplern\25635041
.jpg): Failed to open stream: No such file or directory in C:\Inetpub\vhosts\kidney.de\httpdocs\pget.php on line 117 Genome+Biol+Evol
2015 ; 7
(3
): 642-5
Nephropedia Template TP
gab.com Text
Twit Text FOAVip
Twit Text #
English Wikipedia
An evolutionary classification of genomic function
#MMPMID25635041
Graur D
; Zheng Y
; Azevedo RB
Genome Biol Evol
2015[Jan]; 7
(3
): 642-5
PMID25635041
show ga
The pronouncements of the ENCODE Project Consortium regarding "junk DNA" exposed
the need for an evolutionary classification of genomic elements according to
their selected-effect function. In the classification scheme presented here, we
divide the genome into "functional DNA," that is, DNA sequences that have a
selected-effect function, and "rubbish DNA," that is, sequences that do not.
Functional DNA is further subdivided into "literal DNA" and "indifferent DNA." In
literal DNA, the order of nucleotides is under selection; in indifferent DNA,
only the presence or absence of the sequence is under selection. Rubbish DNA is
further subdivided into "junk DNA" and "garbage DNA." Junk DNA neither
contributes to nor detracts from the fitness of the organism and, hence, evolves
under selective neutrality. Garbage DNA, on the other hand, decreases the fitness
of its carriers. Garbage DNA exists in the genome only because natural selection
is neither omnipotent nor instantaneous. Each of these four functional categories
can be 1) transcribed and translated, 2) transcribed but not translated, or 3)
not transcribed. The affiliation of a DNA segment to a particular functional
category may change during evolution: Functional DNA may become junk DNA, junk
DNA may become garbage DNA, rubbish DNA may become functional DNA, and so on;
however, determining the functionality or nonfunctionality of a genomic sequence
must be based on its present status rather than on its potential to change (or
not to change) in the future. Changes in functional affiliation are divided into
pseudogenes, Lazarus DNA, zombie DNA, and Jekyll-to-Hyde DNA.
free
free
free
