Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Codominance vs Pleiotropism
Name: Rahul
Status: Other
Grade:  12+
Location: Outside U.S.
Country: United States
Date: Spring 2010


Question:
What is the difference between codominance and pleiotropism?



Replies:
Co-dominance is when you have two alleles that both are equally visible in the phenotype. The classic example is blood types-there are A type antigens and B type antigens that each alleles of the same gene. If you get A from Mom and B from Dad you have red blood cells with both types of antigens on them. Type O really means that that allele doesn't code for an antigen, so both A and B are dominant over O.

Pleiotropy is when a gene can be expressed as many different phenotypes throughout the body. Marfan syndrome is an example of a disease that exhibits pleiotropy. It is a disorder that affect collagen production, I believe, which can cause elongated limbs, a weak aorta, difficulties in the lens of the eye, etc. These appear to be unrelated but all owe their cause to a single gene. Here is a link to other phenotypes that are pleiotropic.

http://www.nature.com/scitable/topicpage/Pleiotropy-One-Gene-Can-Affect-Multiple-Traits-569

vanhoeck



Click here to return to the Molecular Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory