User:Kinchiu49/sandbox

The Indy gene (I'm Not Dead Yet) is a gene of the model organism Drosophila melanogaster. Indy codes for a protein in Drosophila similar to sodium dicarobxylate cotransporters in mammals. This protein is responsible for the uptake of Krebs cycle intermediates. Since its discovery, this gene has been under study to determine whether it plays a role in determining the lifespan of Drosophila.

The presence and activity of Indy has been discovered to play a critical role in determining the longevity of Drosophila mutants by Blanka Rogina and her colleagues in 2000. Rogina studied the effect of P element insertions in Indy and the subsequent decrease of Indy activity on Drosophila. Drosophila mutants homozygous for a P element insertion in Indy have exhibited an increase in both mean lifespan and maximal lifespan. Drosophila mutants with a single copy of Indy and a deletion in the Indy region in place of the other copy exhibited a decreased lifespan. While the mechanism by which Indy extends lifespan in Drosophila is currently under study, due to the gene's involvement in metabolic activity it has been hypothesized that Indy extends lifespan of Drosophila in a similar manner as caloric restriction in rodents.

Mechanism
While it is still unclear what the function of Indy is, evidence has been compiled from multiple studies to indicate its involvement in metabolism. The Indy protein is a transmembrane transporter of Krebs cycle intermediates, found predominantly in tissues involved with metabolism as well as nutrient uptake and storage. Mutations to Indy lead to decreased levels of activity of Indy. Due to its close relation to metabolic pathways, it has been hypothesized that the increase in lifespan of Drosophila mutants with P element insertions in Indy is similar in function to rodents undergoing caloric restriction.

Controversy
Not all studies have shown an increase in longevity of Drosophila as a result of mutation to Indy, leading to questioning about the importance of Indy gene activity in determining lifespan in Drosophila mutants. Several studies have been identified where mutations in Indy did not extend lifespan of Drosophila. Differences between results of these studies and Rogina's have been attributed to variation in genetic background in the Drosophila test subjects. Another source of variation between studies has been identified as nutritional conditions. It has been shown that dietary regime of Drosophila plays a role in regulating Indy expression. As variation exists in diets of Drosophila test subjects between studies, not all studies have reached the conclusion that Indy has a strong correlation with longevity in Drosophila. As of yet, there is no consensus as to whether Indy plays a role in determining Drosophila longevity.

Note
This work is all original, minus the very first sentence which came from the stub.