script defer="defer" id="snap_preview_anywhere" type="text/javascript" src="">

Mechanisms of Evolution

Beyond Darwin and Neo-Darwinism


The deletion mutation eliminates one or more nucleotides from a DNA sequence, and may produce a non-functional protein. If the number of deleted bases is not a multiple of 3, then the deletion will cause frameshift, with potentially serious consequences.

Deletion and insertion mutations often occur in repetitive sequences, such as deletion of "AT" from the sequence "ATAT" in the CFTR gene. Such mutations are most often caused by a "replication slippage", where the new strand mispairs with the template strand at repetitive sequences. Slippage can cause mispairing of several repeats. Forward slippage results in deletion mutations, while backward slippage results in insertions.

Replication slippage is mainly responsible for microsatellite polymorphisms, which are also called short tandem repeats (STR). In microsatellites, the repeat unit comprises only 1 to 6 bp and the whole repetitive region spans less than 150 bp, while minisatellites range from 1 to 20 kb, and satellites span from 100 kb to more than 1 Mb.

 Table Mechanisms of Biological Evolution :  Gene Regulation in E.coli :

External : Tandem repeats and morphological variation


Anonymous Anonymous said...

Blue terms hyperlink to explanatory items. Linked items can also be found by way of the 'Links to this post' list at the base of some posts (once Blogger catches up!). Use the "back" function to return to the departure item.

Items occur within Sections. When visiting an item, the site title changes to purple – click on the title or “Home” to return to the main page. Topics are listed in the Site Map (click on arrow at top of sidebar). The site is searchable – once Blogger catches up – by way of the 'Search this blog' window at upper left.

When the number before the “Guide-Glossary” link (below each item) is greater than 0, the link provides a glossary of terms. Displayed as a pop-up when reading within a Section, or as sub-script when visiting an Item.

12:08 PM  

Post a Comment

<< Home

. . . evolving since 10/06/06