This glossary contains a number of definitions from the following publication:
J. M. Cock; Tessmar-Raible, K.; Boyen, C.; Viard, F. (Eds.), Introduction to Marine Genomics, vol. 1, 1st ed., Advances in Marine Genomics Vol. (Springer, 2010). Available from: http://www.springer.com/life+
Term | Definition |
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p-value |
The result of a statistical test can be summarised using a p-value as a measure of significance. It can be described as the confidence in the rejection of the null-hypothesis. In the case of microarrays, p-values are often used to assess whether a gene is differentially expressed. |
PAMP |
Pathogen-Associated Molecular Patterns; Small molecular motifs conserved within a class of microbes; LPS (see above) is considered to be the prototypical PAMP. |
Pangenome |
Unique set of proteins for a given species. In bacteria, the pangenome can be twice the size of the genomes of individual members of a species. |
Paralogue |
Homologous sequences that have been separated by a gene duplication event in an ancestral genome are called paralogous. Paralogous genes may mutate and acquire new functions because the original selective pressure is reduced. |
PCR |
Polymerase chain reaction. A technique for replicating a specific piece of DNA in-vitro. Oligonucleotide primers are added (which initiate the copying of each strand) along with nucleotides and Taq polymerase By cycling the temperature, the target DNA is repeatedly denatured and copied allowing it to be amplified in an exponential manner. |
PDB |
Protein Data Bank. A single worldwide repository for the processing and distribution of 3D biological macromolecular structure data. |
Phytoplankton |
The photosynthetic organisms present in the plankton. |
Picoeukaryotes |
Microscopic eukaryote species with a cell size of less than 3 µm. |
Primary endosymbiosis |
Used to describe the initial capture of a cyanobacterium by a eukaryotic cell that gave rise to the algae (see also endosymbiosis). |
Primer |
Small oligonucleotide (anywhere from 6 to 50 nucleotides long) used to prime DNA synthesis. |
Probe/Reporter |
An oligonucleotide attached to the surface of a microarray. |
Proteomics |
High-throughput analysis of the proteins present in a cell type, a tissue or an organism. |
Pseudogene |
A gene that is no longer functional either because its protein-coding sequence is disrupted or because it is no longer expressed. |
PTM |
Post-transcriptional modification. Alterations made to pre-mRNA before it leaves the nucleus and becomes mature mRNA. |
Pyrosequencing |
Massively parallel DNA sequencing technique without the requirement of a prior cloning of the DNA. |