Evolution
Splicing occurs in all the kingdoms or domains of life, however, the extent and types of splicing can be very different between the major divisions. Eukaryotes splice many protein-coding messenger RNAs and some non-coding RNAs. Prokaryotes, on the other hand, splice rarely and mostly non-coding RNAs. Another important difference between these two groups of organisms is that prokaryotes completely lack the spliceosomal pathway.
Because spliceosomal introns are not conserved in all species, there is debate concerning when spliceosomal splicing evolved. Two models have been proposed: the intron late and intron early models (see intron evolution).
Eukaryotes | Prokaryotes | |
---|---|---|
Spliceosomal | + | − |
Self-splicing | + | + |
tRNA | + | + |
Read more about this topic: RNA Splicing
Famous quotes containing the word evolution:
“The evolution of humans can not only be seen as the grand total of their wars, it is also defined by the evolution of the human mind and the development of the human consciousness.”
—Friedrich Dürrenmatt (19211990)
“Analyze theory-building how we will, we all must start in the middle. Our conceptual firsts are middle-sized, middle-distanced objects, and our introduction to them and to everything comes midway in the cultural evolution of the race.”
—Willard Van Orman Quine (b. 1908)
“The evolution of a highly destined society must be moral; it must run in the grooves of the celestial wheels.”
—Ralph Waldo Emerson (18031882)