"New Genome Comparison Finds Chimps, Humans Very Similar at the DNA Level
":
How are they
different?

   
    Caspases are a family of proteins that act as mediators of apoptosis (programmed cell-death), in which cells die as a normal part of tissue development and differentiation. In chimpanzees, a particular DNA sequence is recognizable as an open reading frame that includes a functional motif (the SHG box) common to other caspase genes. This locus is inferred to be a functional gene, designated Caspase-12.  In the human DNA sequence at the analogous chromosome position, this reading frame is interrupted by a nonsense mutation, and the SHG box is altered as well, such that there is no functional Caspase-12 gene. Absence of a functional protein has been implicated in Alzheimer Disease: analogous mutations in a mouse model interfere with normal amyloid-induced neuronal apoptosis and disrupt calcium homeostasis, both characteristics of the disease.


G. Spencer (2005). New Genome Comparison Finds Chimps, Humans Very Similar at the DNA Level. NIH News, 31 August 2005;
additional text ©2010 by Steven M. Carr