What does Mosaic mean in genetics?
Mosaicism is a condition in which cells within the same person have a different genetic makeup. This condition can affect any type of cell, including: Blood cells. Egg and sperm cells.
What type of mutation is mosaicism?
Mosaicism or genetic mosaicism is a condition in multi-cellular organisms in which a single organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized egg.
What does Mosaic mean in biology?
Mosaic: A person or a tissue that contains two or more types of genetically different cells. All females are mosaics because of X-chromosome inactivation (lyonization). Mosaic patterns can affect the way genetic disorders are expressed.
How does mosaicism affect a mutation?
Mosaicism happens because a mutation occurs at some point after the zygote is created. In general, the later in embryonic development that the mutation occurs, the more restricted in distribution the resulting phenotype is, because the cells derived from a mutated founding cell all carry its mutation.
What causes mosaic?
Mosaicism may be caused by an error in mitosis. Mitosis (my-TOH-sis) is the dividing of body cells. It’s how a baby in the womb grows. Mitosis causes the number of chromosomes to double to 92, and then split in half back to 46.
How does a mosaic occur?
Mosaicism occurs when a person has two or more genetically different sets of cells in his or her body. If those abnormal cells begin to outnumber the normal cells, it can lead to disease that can be traced from the cellular level to affected tissue, like skin, the brain, or other organs.
What is mosaic expression?
In genetics, a mosaic (or mosaicism) means the presence of two different genotypes in an individual which developed from a single fertilized egg. As a result, the individual has two or more genetically different cell lines derived from a single zygote.
How does mosaic trisomy occur?
Mosaic trisomy 9 appears to result from errors of chromosomal separation (nondisjunction) during meiosis, which is the division of reproductive cells (sperm or eggs) in the parents. It has also been shown to occur during cellular division after fertilization (mitosis).
What does a mosaic person mean?
Mosaicism is when a person has 2 or more genetically different sets of cells in their body. Chromosomes are stick-shaped structures in the middle of each cell in the body. Each cell has 46 chromosomes grouped in 23 pairs. A person with mosaicism may have some cells in their body with 46 chromosomes.
What is a mosaic blood type?
The D antigen is a mosaic consisting of several parts, e.g., DABCD. Most people who are D-positive inherit a gene which produces all parts of the D mosaic. Weak D people inherit a gene which produces only part of the mosaic, e.g., DAB , or DBC , etc.