What is a cell?

A cell is the most basic building block of multicellular life. It contains all the elements necessary to carry out life. (NB some specialised cells in multicellular organisms can't carry out everything, relying on other cells to perform certain functions for them).

Top

What is a protein?

A protein is a molecule made up of smaller subunits called amino acids. A number of amino acids joined together is a polypeptide chain (amino acids are sometimes called "peptides"). The chemical nature of these amino acids gives each particular arrangement of a amino acids unique properties; the polypeptide chain will often become folded into a special shape through the properties of the amino acids making them up; certain amino acids are positively or negatively charged, and will attract or repel certain other amino acids, helping to form this pattern. Very complex arrangements of one or more polypeptide chains can form enzymes, the machines which carry out the "work" of life, or they may be structural components of cells, or products of cells.

Top

What is an enzyme?

An enzyme can be thought of as a biological machine; they control or enable most of the chemical reactions of life. Enzymes are frequently described as "biological protein catalysts" which means they are composed of proteins and catalyse (enable or speed up) chemical reactions. All life is made up of thousands of chemical reactions occuring inside of cells - these chemical reactions are more properly called "biochemical" and the study of these reactions is known as "biochemistry".

Top

What are genes and genomes?

The chromosomes are made up a double strand of deoxyribonucleic acid (DNA), consisting of four building blocks, the nucleotides adenine (A), guanine (G), cytosine (C) and thymine (T) - the genetic alphabet. The information is encoded in the sequence of the nucleotides making up DNA (Genes). The information encoded by a gene within the DNA is transcribed into a second type of nucleic acid consisting of ribonucleotides (RNA), which in turn is translated into proteins.

Protein synthesis
Proteins are made from DNA in the following way:
A) The DNA double helix "encodes" proteins by certain arrangements of nucleotides "coding" for certain amino acids. There are 4 nucleotides, and groups of 3 of them (called a "triplet") are "letters" of the protein "alphabet". There are 24 possible combinations of A, C, T and G; most of these stand for particular amino acids; some amino acids are coded for by more than one combination, and some combinations have special "meanings" like Start Here or Stop.
B) A special enzyme, called RNA polymerase travels along the DNA strand, making a strand of mRNA (messenger RNA) (C) which is a mirror image of the DNA. This process is called transcription. This mRNA leaves the nucleus, and travels out into the cell.
A ribosome (D), a very large molecule attaches to the mRNA. This ribosome travels along the mRNA, and allows tRNA (transfer RNA) molecules with amino acids attached to them to bind to the mRNA molecule. The ribosome "checks" that the tRNA that has bound to the mRNA is the correct one, and then joins the amino acids carried on the tRNA together, forming a polypeptide chain (E) (this is the simplest kind of protein). This process is known as translation.

A ribosome is the "machine" that creates polypeptide chains from the raw materials of mRNA and tRNA with attached amino acids.

Genomics is the study of the genome in terms of its structure (nucleotide sequence) and function - the regulation of gene expression (production of proteins and their activity in the cell).

Top

What is a genome resource?

For the coelcanth programme, this includes all the genetic material in the cell including:

DNA - Nuclear and mitochondrial chromosomes. DNA will be extracted from tissue e.g. muscle, blood, skin etc.

Messenger RNA - messages from active genes expressed in specific tissues e.g. brain, spinal column, gonads, muscle, liver, blood etc.

Tissue culture cell lines These will be established from skin samples associated with scales and will be either primary or immortalized cell lines.

Top

What will the genome resource be used for?

Primary objectives:

Extracted DNA will be used to construct "libraries" which will be used to determine the nucleotide sequence of selected genes and gene clusters on the coelacanth genome. These genes include those encoding cell stress and cytoprotection-related proteins and proteins involved in developmental regulation.

Tissue culture cell lines will be used to develop an in vitro (test tube) biological system for styling the expression of coelacanth genes in the laboratory. They may also serve as a potential source of mRNA and DNA.