What is a pleiotropic mutation?

A mutation that affects expression of several characteristics, e.g. the effect of mutation of a promoter on structural genes regulated by it.

What is pleiotropy give an example?

One of the most widely cited examples of pleiotropy in humans is phenylketonuria (PKU). This disorder is caused by a deficiency of the enzyme phenylalanine hydroxylase, which is necessary to convert the essential amino acid phenylalanine to tyrosine.

What are the diseases caused by pleiotropy?

One example of pleiotropy is Marfan syndrome, a human genetic disorder affecting the connective tissues. This disease commonly affects the eyes, heart, blood vessels, and skeleton. Marfan Syndrome is caused by a mutation in a human gene resulting in pleiotropy.

Why is pleiotropy so common?

We have known for decades that pleiotropy is widespread because in plant and animal breeding, and in laboratory selection experiments, when selection is applied to one trait, the mean of other traits also changes from generation to generation.

Is a polymorphism a mutation?

A mutation is defined as any change in a DNA sequence away from normal. This implies there is a normal allele that is prevalent in the population and that the mutation changes this to a rare and abnormal variant. In contrast, a polymorphism is a DNA sequence variation that is common in the population.

What is the difference between pleiotropy and epistasis?

The basic difference between epistasis and pleiotropy is that epistasis is the phenomenon in which a gene at one site changes the phenotypic expression of a gene at another location whereas pleiotropy explains the phenomenon in which a single gene affects several phenotypic traits.

Is pleiotropy a disorder?

Pleiotropy refers to disorders where multiple, seemingly unrelated organ systems are affected. For example, one individual in a pedigree may exhibit cardiac arrhythmia, whereas another individual with the same disorder in either the same or different pedigree shows muscle weakness and deafness.

Why is pleiotropy not surprising?

Bottom: Pleiotropy is often considered ‘spurious’ when the multiple affected traits cannot be connected directly to a single gene. For example, two genes may be strongly linked, resulting in the observation of a single genetic locus influencing multiple phenotypes.

What is the difference between an allele and a mutation?

Mutations Are Recessive or Dominant Different forms of a gene (e.g., normal and mutant) are referred to as alleles. Since diploid organisms carry two copies of each gene, they may carry identical alleles, that is, be homozygous for a gene, or carry different alleles, that is, be heterozygous for a gene.

How does DNA mapping work?

To produce a genetic map, researchers collect blood or tissue samples from members of families in which a certain disease or trait is prevalent. DNA markers don’t, by themselves, identify the gene responsible for the disease or trait; but they can tell researchers roughly where the gene is on the chromosome.

Why does a mutation in a pleiotropic gene cause multiple traits?

Pleiotropy. Such a gene that exhibits multiple phenotypic expression is called a pleiotropic gene. Mutation in a pleiotropic gene may have an effect on several traits simultaneously, due to the gene coding for a product used by a myriad of cells or different targets that have the same signaling function.

How does pleiotropy limit the rate of multivariate evolution?

Pleiotropic gene action can limit the rate of multivariate evolution when natural selection, sexual selection or artificial selection on one trait favors one allele, while selection on other traits favors a different allele. Some gene evolution is harmful to an organism.

Which is an example of a pleiotropic phenotype?

Phenotypes are traits that are physically expressed such as color, body shape, and height. It is often difficult to detect which traits may be the result of pleitoropy unless a mutation occurs in a gene. Because pleiotropic genes control multiple traits, a mutation in a pleiotropic gene will impact more than one trait.

Which is the underlying mechanism of pleiotropy?

Mechanism. Pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is genes that code for a product that is either used by various cells or has a cascade-like signaling function that affects various targets.

What is a pleiotropic mutation? A mutation that affects expression of several characteristics, e.g. the effect of mutation of a promoter on structural genes regulated by it. What is pleiotropy give an example? One of the most widely cited examples of pleiotropy in humans is phenylketonuria (PKU). This disorder is caused by a deficiency of…