Jumping genes

Article Abstract:

Jumping genes were originally thought to exist only in plants and bacteria, but they also may play a role in human disease. Barbara McClintock won the Nobel prize in 1983 for discovering that genes are not permanently fixed on chromosomes, but can and do move around. Genes are often recombined during meiosis, the process by which the male and female sex cells are formed. However, transposition of genes can also occur in somatic, or body, cells. Some jumping genes called transposons insert themselves into DNA in much the same way some viruses do. When this happens, the disruption of the existing gene can cause the expression of altered proteins that can cause disease. Hemophilia A, familial hypercholesterolemia and retinitis pigmentosa are examples of diseases that may be caused by jumping genes. Certain cancers are caused by an exchange of material between two chromosomes, which can also disrupt the normal function of the existing genes.

Health aspects, Transposons, Familial diseases

---

Molecular medicine: jumping genes and the immunoglobulin V gene system

Article Abstract:

The immune system can produce a tremendous variety of B cells by assembling different combinations of variable region genes (V genes) that code for antigen receptors. Each kind of B cell produces a specific immunoglobulin which is placed in the cell membrane and acts as an antigen receptor. An immature B cell cuts and splices DNA to generate specific Y-shaped receptors. The arms of the Y are variable and coded for by different V genes. The stem of the Y consists of 1 of 5 types of immunoglobulins. After cutting and splicing V genes, the B cell can alter the gene further by cutting ar adding nucleotides to the ends. The B cells that match an antigen that is present in the body will reproduce much more than other B cells. Labelling for specific receptors can be used to identify B cells that have multiplied too much and caused leukemia or lymphoma. Specific antibodies can also be produced artificially for patients, by manipulating V genes.

Physiological aspects, Molecular genetics

---

Agammaglobulinemia and insights into B-cell differentiation

Article Abstract:

A group of children with agammaglobulinemia reveals that the mu chain of immunoglobulin is necessary for B cell development. Agammaglobulinemia is characterized by an absence of gamma globulins, which are antibodies produced by B cells. These children have persistent bacterial infections because their B cells cannot create antibodies. Many patients with this disease have mutations in the gene for an enzyme called tyrosine kinase. However, a 1996 study revealed that a group of children with agammaglobulinemia had mutations in the mu chain, which is expressed on the surface of B cells during their development.

Editorial, Gene mutations, Gene mutation, Identification and classification, Agammaglobulinemia

Similar abstracts:

• Abstracts: Teasing out the tangles. AIDS meeting spotlights pills to prevent infection. The amyloid code
• Abstracts: Improving practice in wound care for patients with dementia
• Abstracts: Disentangling mild traumatic brain injury and stress reactions. Combat duty in Iraq and Afghanistan, mental health problems, and barriers to care
• Abstracts: Early interactions between drug-involved mothers and infants: within-group differences. What is important about a study of within-group differences of 'cocaine babies?'(Editorial)
• Abstracts: Reproducibility of a food frequency questionnaire and stability of dietary habits determined from five annually repeated measurements

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.