Phenotypic plasticity

Phenotypic plasticity is variation within an organism's phenotype. It is the ability for the phenotype of an organism to achieve variation in response to environmental triggers, rather than genes alone. This is a significant factor to consider within the field of epigenetics. The term phenotypic plasticity was originally put forth as a descriptor for morphogenesis of structures but is now more generally applied to include the changes that occur during the adult life of an organism as well.

Observation and Experimentation
Phenotypic plasticity can be seen in many different organisms but one specific case is how abdominal pigmentation changes in Drosophila melangaster females. These changes are seen to be the result of environmental fluctuations in temperature and light. Findings were published in the peer-reviewed journal PLoS Genetics in February of 2007 in a paper titled, Phenotypic Plasticity in Drosophila Pigmentation Caused by Temperature Sensitivity of a Chromatin Regulator Network.

These changes are caused by a homeotic gene that is called Abdominal-B (Abd-B). It is shown to be a major factor in the plasticity of pigmentation in the posterior abdomen. Abd-B causes both light and dark melanin production in Drosophila through disruption of the regulation of several pigmentation enzymes. Genes that are controlled by temperature affect the regulation of chromosome architecture, resulting in either a dark colored or light colored abdomen.