The daf-2 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

 encodes an insulin

Insulin

Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....

-like receptor

Receptor (biochemistry)

In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...

 in the worm C. elegans

Caenorhabditis elegans

Caenorhabditis elegans is a free-living, transparent nematode , about 1 mm in length, which lives in temperate soil environments. Research into the molecular and developmental biology of C. elegans was begun in 1974 by Sydney Brenner and it has since been used extensively as a model...

. Mutation

Mutation

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

s in daf-2 have been shown by Cynthia Kenyon

Cynthia Kenyon

Cynthia Jane Kenyon is an American molecular biologist and biogerontologist known for her genetic dissection of aging in a tiny worm, Caenorhabditis elegans.-Career:...

 to double the lifespan of the worms. The gene is known to regulate reproductive development, aging, resistance to oxidative stress

Oxidative stress

Oxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...

, thermotolerance, resistance to hypoxia

Hypoxia (medical)

Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...

, and also resistance to bacterial pathogens.

DAF-2 is the only insulin/IGF-1 like receptor in the worm. Insulin/IGF-1-like signaling is conserved from worms to human

Human

Humans are the only living species in the Homo genus...

s. Unlike in higher eukaryotes, however, both human insulin as well as some insulin orthologs coded for by C. elegans ins genes antagonize

Receptor antagonist

A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...

 the DAF-2 receptor leading to inhibition of the pathway as opposed to activation of DAF-2 signaling. DAF-2 acts to negatively regulate the forkhead transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

 Daf-16

Daf-16

DAF-16 is part of a group of genes that drive the biological processes involved in ageing, immunity and responses to physical or environmental stresses...

 through a phosphorylation

Phosphorylation

Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....

 cascade. Genetic analysis reveals that DAF-16 is required for daf-2-dependent lifespan extension and dauer

Dauer

Dauer may refer to:* Jochen Dauer, a former German race car driver, leather magnate, and proprietor of Dauer Sportwagen GmbH, notable for converting Porsche 962 race cars for use on the road as Dauer 962 Le Mans...

 formation. When not phosphorylated, DAF-16 is active and present in the nucleus

Cell nucleus

In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

.