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Gene
| What it's not: |
Something blue and expensive made of cheap material. |
| What it is: |
Genes are both units of inheritance and encoded messages for the creation of a functional unit in a cell (usually a protein, but sometimes functional RNA). Anyway, these functional units determine, among other things, an organism’s appearance, its metabolism and sometimes even its behaviour. As far as the size of human genes goes, the average is around 3,000 base pairs, while the largest human gene, dystrophin, incorporates 2.4 million base pairs. (Mutated dystrophin leads to Duchenne and Becker muscular dystrophy.) |
Gene Expression
| What it's not: |
Phrases like, “Oooh, she’s got her mother’s eyes.” |
| What it is: |
This is the process that gets a gene’s information to the rest of the cell and/or world. When a gene is “expressed”, it is “on” and in RNA-production mode. Sometimes this RNA can be functional on its own but usually it’s converted into a protein. Either way, the gene’s information is out there to impact the individual’s phenotype. |
Gene Family
| What it's not: |
What Levis©, Wrangler© and Buffalo© belong to.. |
| What it is: |
A gene family is a set of genes similar in DNA sequence. Their similarity is presumably due to their evolution from a single ancestral gene that duplicated. Although these gene products gained or lost functions over time and became slightly different from their common ancestor, remnants of the ancestral gene are still present in all family members. |
Gene Knockout
| What it's not: |
A very attractive bit of DNA. |
| What it is: |
It’s possible to delete a particular gene in an organism without harming the surrounding cell. In a gene knockout mouse for example, scientists use this technique to study the physical phenotypic effects in mice of specific mutations similar to human ones. |
Gene Therapy
| What it's not: |
Very similar to 'shopping therapy', when you treat yourself to some new denim and feel better. |
| What it is: |
The aim is to be able to identify and replace ‘faulty’ genes involved in inherited diseases or defects in an embryo, or regular person (somatic therapy) foetus with ‘corrected’ versions. This is not as yet a practical possibility for most defects. Even though the developing techniques of gene therapy appear to hold some promise for diseases that result from changes in a single gene (cystic fibrosis & Duchenne muscular dystrophy being just two), the majority of diseases are the result of a bafflingly complex interplay of many genes and their interaction with environment. It will therefore be truly difficult to eliminate these conditions with the emerging principles of gene therapy. |
Genetic Counselor
| What it's not: |
Where genes go for therapy |
| What it is: |
Genetic counsellors are health professionals
that provide information and support to families at risk for or affected
by a genetic condition. Genetic counsellors translate complex genetic
information into everyday language to help people make informed decisions
about the issue at hand. They strive to discuss information and present
options in a non-biased way to encourage patients to make decisions
fitting with their own personal values and beliefs. |
Genetic Engineering
| What it's not: |
The process by which genes are made colours other than blue. |
| What it is: |
‘Genetic engineering’ is the manipulation of an organism’s genetic material by introducing new DNA into it, most often via viruses, which are most naturally accommodating for this kind of special assignment. The techniques of genetic engineering are used to produce new varieties of plants and bacteria that act as factories for the production human hormones & vaccines. For example, insulin for diabetics used to be isolated from horses and the “drug” was expensive [and not exactly perfect for humans]. Now, insulin is produced from the human gene engineered into bacteria that are grown in large vats. Because it is now easier to obtain, the “drug” is relatively inexpensive. (This also holds true for antibiotics – often the newer, expensive antibiotics are not yet cloned so they are expensive, whereas garden variety drugs like penicillin are grown in vats.) |
Genetic Testing
| What it's not: |
What they’ll never do at border crossings |
| What it is: |
These are any procedure to determine predisposition to disease or confirm diagnosis of genetic disease. The type of test can vary and different agencies or governing bodies interpret the term differently, where some say that it refers only to tests on DNA and others say that tests can include gene products. For example, instead of testing for the mutation in the DNA, you can test for the abnormal metabolite found in someone with that genetic disorder. Because other family members are tested in some types of testing, genetic tests can also be used to prove paternity. It is important that genetic counselling be part of the process to make sure that patients understand the test and the results. |
Genetically Modified Organisms (GMO)
| What it's not: |
A new rock band, originally from the
L.A. punk scene. |
| What it is: |
A GMO is an organism (plant, animal or
microorganisms) that has had its genetic material altered in order to
give the organism new characteristics that are not naturally found in
the organism. For example, the DNA from food crops may be genetically
modified to increase the crop’s resistance to insects or disease,
or to improve taste. |
Genome
| What it's not: |
A tiny person; a garden statue of a tiny person. |
| What it is: |
The genome is the entire genetic information content of an
organism. In other words, the human genome is the genetic content of humans
and the chimpanzee genome refers to…wait for it…the genetic
material of chimpanzees. When we hear that a ‘genome has been
sequenced’, it means that all the base pairs (A, T, C, and G) have been
determined for an organism. |
Genomics
| What it's not: |
The science that studies tiny people; science done by scientists of diminutive stature. |
| What it is: |
Genomics aims to decipher and understand the entire genetic information content of an organism. As such, this science is fundamental to all biological (and biotech) research. It differs from classical biological research in its large scale, broad scope and intense reliance on data collection, analysis and information technology (bioinformatics). Genomics is consequently recognized as genormously important to the future of the biotechnology industry. |
Genotype
| What it's not: |
Having the nature of a diminutive scientist, but not necessarily the appearance of one. |
| What it is: |
The specific set of alleles contained in the DNA of a specific organism. You can’t see your genotype in the mirror– or anybody else’s, either– without special scientific tools. As to what you can see some of in the mirror, see phenotype. |
Genotype-phenotype correlation
| What it's not: |
A scientific principle describing the
relationship between the pants people buy and their body type
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What it is:
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Genotype phenotype correlation is when
a particular genotype seems to be linked to (or can predict) what the
phenotype is. For example, say it was determined that a person who has
red hair, always has the genotype rr at a particular locus, where as
the genotypes bb and ww are not seen with red hair. You could say that
there appears to be a link (or correlation) between rr (the genotype)
and red hair (the phenotype). In medical genetics a genotype phenotype
correlation would be when a particular gene mutation is known to cause
a genetic disorder.
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Germ Line
| What it's not: |
A ring around the bathtub |
| What it is: |
The cells that give rise to gametes (sperm or eggs). Mutations in these cells can be passed onto future generations. Although gene therapy is essentially still experimental (and contentious), its use underscores the distinction between the somatic and germ lines. Some believe that instead of treating genetic disorders with somatic gene therapy, the mutated gene should be permanently fixed by removing the mutation forever. To do this, the mutation must be replaced in the germ line so the “correct” version of the gene is given to the next generation. |
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