BioScience Dictionary

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Ot.

Found Expression 48 times.

Displaying results 1 to 10.

1. Ambisense expression strategy
The coding of viral protein s in both the sense (coding) and antisense (noncoding) strands of complementary mRNA , so that the viral proteins are produced no matter which strand gets translated .

2. Attenuator
An RNA sequence that regulates the expression of certain gene s by terminating transcription .

3. Caenorhabiditis elegans
This is a free-living (non parasitic) species of nematode which makes a good model organism for biological study because it has a small genome of only six chromosome s. It also has a short generation time of about three days (at room temperature), and is easy to grow at high densities (up to 10,000 worms on one Petri dish). C. elegans has been thoroughly studied by geneticist s, developmental biologist s and neurologists. The worms can be used to study genetic manipulation , gene therapy , and the molecular basis of differentiation during development. Much of the world's knowledge about aging, inheritance, and the factors which control gene expression during development comes from studying this and other nematodes. The full taxonomic classification of C. elegans is: kingdom Animalia, phylum Nematoda, class Secernentea, subclass Rhabditia, order Rhabditida, family Rhabditidae.

4. Carcinoembryonic antigen (CEA)
This is an antigen in blood which is elevated in certain cancers of epithelial origin, notably colon, breast, lung and stomach. CEA is a molecule expressed on surfaces of epithelial cells during embryogenesis but is later confined to only the apical surface. Its function is related to cell adhesions. Tumor formation is accompanied with elevated expression of CEA. Blood CEA levels is a tumor marker to detect the recurrence of cancer or residual activity of cancer after surgery. However, CEA is a non-specific marker of cancer, and may be elevated in noncancerous conditions such as cigarette smoking, ulcerative colitis, liver disease, and lung infection. Therefore, CEA is not useful as a screening test. (Normal levels of serum carcinoembryonic antigen are 0 to 2.5 ug/L.)

5. Coordinate regulation
The expression of many different gene s at once.

6. CpG-rich islands
Areas of DNA which consist mostly of the base pair sequence CGCGCGCG... (alternating cytosine and guanine nucleotide base s) that are usually found upstream of many gene s and are thought to help regulate gene expression . They are often methylated (have methyl group s attached to the DNA segments).

7. Dominance
The property of one of a pair of alleles that suppresses the expression of the other member of the pair in heterozygotes .

8. Down promoter mutation
A mutation (a change in base pair sequence) in a promoter region; this results in lower gene expression (less transcription of the gene occurs).

9. Early genes
The gene s of a virus which are expressed first, soon after the virus infects its host . Generally, they replicate the viral genome and signal expression of the late genes of the virus at a later point in the viral life cycle.

10. Ecdysone
Any of several insect hormone s that triggers the expression of critical gene s during larval development; these hormones are being researched as safer alternatives to pesticide s.

View web definitions »

Learn more about Expression »