Gulonolactone oxidase

L-gulonolactone oxidase is an enzyme that catalyzes the reactions needed to produce ascorbic acid (vitamin c). This gene is present in most animals however it has been inactivated due to mutation in some. Animals that can no longer synthesize vitamin c include: simians, guinea pigs, and several species of fruit bats. Since these organisms consume a large portion of their diet in fruit the inactivation of the gene was not a significant detriment. Humans that fail to eat sources of vitamin c can develop scurvy.

The mutation that causes the inactivation of the L-gulonolactone oxidase gene is different depending on the group the organism is in. Guinea pigs share the same inactivation mutation, as do all simians. The likelihood of two different species sharing the same inactivation mutation is statistically impossible and is actually shared due to common inheritance. The most recent common ancestor of all extant guinea pigs developed the mutation in the gene, the same for simians including humans.

There are multiple examples of these kinds of inactivated genes across all extant species, the term pseudogenes is used to label all of these.

References

• http://www.ihop-net.org/UniPub/iHOP/gismo/88910.html GLUOP from IHOP