Question

What is a heterochronic mutation? How does it affect the phenotypic outcome of an organism? What phenotypic effects would you expect if a heterochronic mutation affected the cell lineage that determines the fates of intestinal cells?

Short answer

A heterochronic mutation is a genetic change that alters the timing or rate of an organism's development, leading to various potential phenotypic outcomes. If such a mutation were to affect the cell lineage that determines the fate of intestinal cells, it could lead to significant changes in the structure and functionality of the intestines.

Step-by-step solution

Define a Heterochronic Mutation

A heterochronic mutation is a genetic mutation that affects the timing or rate of developmental processes within an organism. It can lead to modifications in body plan and different phenotypes across species.

Explain the Impact on the Phenotypic Outcome

The timing of events in an organism's development is critical. Changes in this schedule, due to a heterochronic mutation, could make significant changes to the organism's final form (phenotype). For example, if a heterochronic mutation caused a developmental process to occur earlier than usual, the organism might become larger or mature sooner than others of its species.

Predict the effect on intestinal cell lineage

If a heterochronic mutation affected the cell lineage that determines the fates of intestinal cells, it could lead to significant alterations in the structure and function of the intestines. For example, it could lead to more rapid cell division, leading to an unusually large intestine. Alternatively, it could disrupt the normal differentiation of cells, leading to a lack of necessary functional cell types in the intestine.