Pleiotropy
Pleiotropy
Pleiotropy is the manifestation of several traits present in an organism, which are caused by a single Gene. [1]
The outcome of these crosses stray from the normal Mendelian Ratios. This is due to lethal alleles resulting in some crosses producing a lethal genotype. An example of this is known in Manx cats. Manx cats carry a Dominant mutation which affects spinal formation in cats. This leads to the tail of the cat being shorter, or not developing at all. The ratio of genotypes produced when two manx cats are crossed is 2:1, this is not the expected Mendelian ratio of 3:1. This is because the Homozygous Dominant genotype is lethal, meaning the embryo does not develop. The Phenotypic ratio produced is therfore1 normal: 2 Manx. [2]
References:
- ↑ http://www.nature.com/scitable/topicpage/pleiotropy-one-gene-can-affect-multiple-traits-569
- ↑ Reference to the book: Genetics: Ananlysis and Principles, Robert J. Brooker, Granite hill publishers 2009.